def __init__(self, target=None, listeners=None, name=None, service=None, cleanup_method=None, **kwargs):
"""
Constructs an ION process.
You don't create one of these directly, the IonProcessThreadManager run by a container does this for
you via the ProcManager interface. Call the container's spawn_process method and this method will run.
@param target A callable to run in the PyonThread. If None (typical), will use the target method
defined in this class.
@param listeners A list of listening endpoints attached to this thread.
@param name The name of this ION process.
@param service An instance of the BaseService derived class which contains the business logic for
an ION process.
@param cleanup_method An optional callable to run when the process is stopping. Runs after all other
notify_stop calls have run. Should take one param, this instance.
"""
self._startup_listeners = listeners or []
self.listeners = []
self.name = name
self.service = service
self._cleanup_method = cleanup_method
self.thread_manager = ThreadManager(failure_notify_callback=self._child_failed) # bubbles up to main thread manager
self._ctrl_queue = Queue()
self._ready_control = Event()
PyonThread.__init__(self, target=target, **kwargs)
def __init__(self,
target=None,
listeners=None,
name=None,
service=None,
cleanup_method=None,
heartbeat_secs=10,
**kwargs):
"""
Constructs an ION process.
You don't create one of these directly, the IonProcessThreadManager run by a container does this for
you via the ProcManager interface. Call the container's spawn_process method and this method will run.
@param target A callable to run in the PyonThread. If None (typical), will use the target method
defined in this class.
@param listeners A list of listening endpoints attached to this thread.
@param name The name of this ION process.
@param service An instance of the BaseService derived class which contains the business logic for
an ION process.
@param cleanup_method An optional callable to run when the process is stopping. Runs after all other
notify_stop calls have run. Should take one param, this instance.
@param heartbeat_secs Number of seconds to wait in between heartbeats.
"""
self._startup_listeners = listeners or []
self.listeners = []
self._listener_map = {}
self.name = name
self.service = service
self._cleanup_method = cleanup_method
self.thread_manager = ThreadManager(
failure_notify_callback=self._child_failed
) # bubbles up to main thread manager
self._dead_children = [] # save any dead children for forensics
self._ctrl_thread = None
self._ctrl_queue = Queue()
self._ready_control = Event()
self._errors = []
self._ctrl_current = None # set to the AR generated by _routing_call when in the context of a call
# processing vs idle time (ms)
self._start_time = None
self._proc_time = 0
# for heartbeats, used to detect stuck processes
self._heartbeat_secs = heartbeat_secs # amount of time to wait between heartbeats
self._heartbeat_stack = None # stacktrace of last heartbeat
self._heartbeat_time = None # timestamp of heart beat last matching the current op
self._heartbeat_op = None # last operation (by AR)
self._heartbeat_count = 0 # number of times this operation has been seen consecutively
PyonThread.__init__(self, target=target, **kwargs)
def __init__(self,
target=None,
listeners=None,
name=None,
service=None,
**kwargs):
self._startup_listeners = listeners or []
self.listeners = []
self.name = name
self.service = service
self.thread_manager = ThreadManager(
failure_notify_callback=self._child_failed
) # bubbles up to main thread manager
self._ctrl_queue = Queue()
PyonThread.__init__(self, target=target, **kwargs)
def __init__(self, target=None, listeners=None, name=None, service=None, **kwargs):
self._startup_listeners = listeners or []
self.listeners = []
self.name = name
self.service = service
self.thread_manager = ThreadManager(failure_notify_callback=self._child_failed) # bubbles up to main thread manager
self._ctrl_queue = Queue()
PyonThread.__init__(self, target=target, **kwargs)
def __init__(self, target=None, listeners=None, name=None, service=None, cleanup_method=None,
heartbeat_secs=10, **kwargs):
"""
Constructs the control part of an ION process.
Used by the container's IonProcessThreadManager, as part of spawn_process.
@param target A callable to run in the PyonThread. If None (typical), will use the target method
defined in this class.
@param listeners A list of listening endpoints attached to this thread.
@param name The name of this ION process.
@param service An instance of the BaseService derived class which contains the business logic for
the ION process.
@param cleanup_method An optional callable to run when the process is stopping. Runs after all other
notify_stop calls have run. Should take one param, this instance.
@param heartbeat_secs Number of seconds to wait in between heartbeats.
"""
self._startup_listeners = listeners or []
self.listeners = []
self._listener_map = {}
self.name = name
self.service = service
self._cleanup_method = cleanup_method
self.thread_manager = ThreadManager(failure_notify_callback=self._child_failed) # bubbles up to main thread manager
self._dead_children = [] # save any dead children for forensics
self._ctrl_thread = None
self._ctrl_queue = Queue()
self._ready_control = Event()
self._errors = []
self._ctrl_current = None # set to the AR generated by _routing_call when in the context of a call
# processing vs idle time (ms)
self._start_time = None
self._proc_time = 0 # busy time since start
self._proc_time_prior = 0 # busy time at the beginning of the prior interval
self._proc_time_prior2 = 0 # busy time at the beginning of 2 interval's ago
self._proc_interval_num = 0 # interval num of last record
# for heartbeats, used to detect stuck processes
self._heartbeat_secs = heartbeat_secs # amount of time to wait between heartbeats
self._heartbeat_stack = None # stacktrace of last heartbeat
self._heartbeat_time = None # timestamp of heart beat last matching the current op
self._heartbeat_op = None # last operation (by AR)
self._heartbeat_count = 0 # number of times this operation has been seen consecutively
self._log_call_exception = CFG.get_safe("container.process.log_exceptions", False)
self._log_call_dbstats = CFG.get_safe("container.process.log_dbstats", False)
self._warn_call_dbstmt_threshold = CFG.get_safe("container.process.warn_dbstmt_threshold", 0)
PyonThread.__init__(self, target=target, **kwargs)
def __init__(
self, target=None, listeners=None, name=None, service=None, cleanup_method=None, heartbeat_secs=10, **kwargs
):
"""
Constructs an ION process.
You don't create one of these directly, the IonProcessThreadManager run by a container does this for
you via the ProcManager interface. Call the container's spawn_process method and this method will run.
@param target A callable to run in the PyonThread. If None (typical), will use the target method
defined in this class.
@param listeners A list of listening endpoints attached to this thread.
@param name The name of this ION process.
@param service An instance of the BaseService derived class which contains the business logic for
an ION process.
@param cleanup_method An optional callable to run when the process is stopping. Runs after all other
notify_stop calls have run. Should take one param, this instance.
@param heartbeat_secs Number of seconds to wait in between heartbeats.
"""
self._startup_listeners = listeners or []
self.listeners = []
self._listener_map = {}
self.name = name
self.service = service
self._cleanup_method = cleanup_method
self.thread_manager = ThreadManager(
failure_notify_callback=self._child_failed
) # bubbles up to main thread manager
self._dead_children = [] # save any dead children for forensics
self._ctrl_thread = None
self._ctrl_queue = Queue()
self._ready_control = Event()
self._errors = []
self._ctrl_current = None # set to the AR generated by _routing_call when in the context of a call
# processing vs idle time (ms)
self._start_time = None
self._proc_time = 0
# for heartbeats, used to detect stuck processes
self._heartbeat_secs = heartbeat_secs # amount of time to wait between heartbeats
self._heartbeat_stack = None # stacktrace of last heartbeat
self._heartbeat_time = None # timestamp of heart beat last matching the current op
self._heartbeat_op = None # last operation (by AR)
self._heartbeat_count = 0 # number of times this operation has been seen consecutively
PyonThread.__init__(self, target=target, **kwargs)
class IonProcessThread(PyonThread):
"""
Form the base of an ION process.
"""
def __init__(self, target=None, listeners=None, name=None, service=None, cleanup_method=None, heartbeat_secs=10, **kwargs):
"""
Constructs an ION process.
You don't create one of these directly, the IonProcessThreadManager run by a container does this for
you via the ProcManager interface. Call the container's spawn_process method and this method will run.
@param target A callable to run in the PyonThread. If None (typical), will use the target method
defined in this class.
@param listeners A list of listening endpoints attached to this thread.
@param name The name of this ION process.
@param service An instance of the BaseService derived class which contains the business logic for
an ION process.
@param cleanup_method An optional callable to run when the process is stopping. Runs after all other
notify_stop calls have run. Should take one param, this instance.
@param heartbeat_secs Number of seconds to wait in between heartbeats.
"""
self._startup_listeners = listeners or []
self.listeners = []
self._listener_map = {}
self.name = name
self.service = service
self._cleanup_method = cleanup_method
self.thread_manager = ThreadManager(failure_notify_callback=self._child_failed) # bubbles up to main thread manager
self._dead_children = [] # save any dead children for forensics
self._ctrl_thread = None
self._ctrl_queue = Queue()
self._ready_control = Event()
self._errors = []
self._ctrl_current = None # set to the AR generated by _routing_call when in the context of a call
# processing vs idle time (ms)
self._start_time = None
self._proc_time = 0
# for heartbeats, used to detect stuck processes
self._heartbeat_secs = heartbeat_secs # amount of time to wait between heartbeats
self._heartbeat_stack = None # stacktrace of last heartbeat
self._heartbeat_time = None # timestamp of heart beat last matching the current op
self._heartbeat_op = None # last operation (by AR)
self._heartbeat_count = 0 # number of times this operation has been seen consecutively
PyonThread.__init__(self, target=target, **kwargs)
def heartbeat(self):
"""
Returns a tuple indicating everything is ok.
Should only be called after the process has been started.
Checks the following:
- All attached endpoints are alive + listening (this means ready)
- The control flow greenlet is alive + listening or processing
@return 3-tuple indicating (listeners ok, ctrl thread ok, heartbeat status). Use all on it for a
boolean indication of success.
"""
listeners_ok = True
for l in self.listeners:
if not (l in self._listener_map and not self._listener_map[l].proc.dead and l.get_ready_event().is_set()):
listeners_ok = False
ctrl_thread_ok = self._ctrl_thread.running
# are we currently processing something?
heartbeat_ok = True
if self._ctrl_current is not None:
st = traceback.extract_stack(self._ctrl_thread.proc.gr_frame)
if self._ctrl_current == self._heartbeat_op:
if st == self._heartbeat_stack:
self._heartbeat_count += 1 # we've seen this before! increment count
# we've been in this for the last X ticks, or it's been X seconds, fail this part of the heartbeat
if self._heartbeat_count > CFG.get_safe('cc.timeout.heartbeat_proc_count_threshold', 30) or \
int(get_ion_ts()) - int(self._heartbeat_time) >= CFG.get_safe('cc.timeout.heartbeat_proc_time_threshold', 30) * 1000:
heartbeat_ok = False
else:
# it's made some progress
self._heartbeat_count = 1
self._heartbeat_stack = st
self._heartbeat_time = get_ion_ts()
else:
self._heartbeat_op = self._ctrl_current
self._heartbeat_count = 1
self._heartbeat_time = get_ion_ts()
self._heartbeat_stack = st
else:
self._heartbeat_op = None
self._heartbeat_count = 0
return (listeners_ok, ctrl_thread_ok, heartbeat_ok)
@property
def time_stats(self):
"""
Returns a 3-tuple of (total time, idle time, processing time), all in ms.
"""
now = int(get_ion_ts())
running_time = now - self._start_time
idle_time = running_time - self._proc_time
return (running_time, idle_time, self._proc_time)
def _child_failed(self, child):
"""
Occurs when any child greenlet fails.
Propogates the error up to the process supervisor.
"""
# remove the child from the list of children (so we can shut down cleanly)
for x in self.thread_manager.children:
if x.proc == child:
self.thread_manager.children.remove(x)
break
self._dead_children.append(child)
# kill this main, we should be noticed by the container's proc manager
self.proc.kill(child.exception)
def add_endpoint(self, listener):
"""
Adds a listening endpoint to be managed by this ION process.
Spawns the listen loop and sets the routing call to synchronize incoming messages
here. If this process hasn't been started yet, adds it to the list of listeners
to start on startup.
"""
if self.proc:
listener.routing_call = self._routing_call
if self.name:
svc_name = "unnamed-service"
if self.service is not None and hasattr(self.service, 'name'):
svc_name = self.service.name
listen_thread_name = "%s-%s-listen-%s" % (svc_name, self.name, len(self.listeners)+1)
else:
listen_thread_name = "unknown-listener-%s" % (len(self.listeners)+1)
self._listener_map[listener] = self.thread_manager.spawn(listener.listen, thread_name=listen_thread_name)
self.listeners.append(listener)
else:
self._startup_listeners.append(listener)
def remove_endpoint(self, listener):
"""
Removes a listening endpoint from management by this ION process.
If the endpoint is unknown to this ION process, raises an error.
@return The PyonThread running the listen loop, if it exists. You are
responsible for closing it when appropriate.
"""
if listener in self.listeners:
self.listeners.remove(listener)
return self._listener_map.pop(listener)
elif listener in self._startup_listeners:
self._startup_listeners.remove(listener)
return None
else:
raise IonProcessError("Cannot remove unrecognized listener: %s" % listener)
def target(self, *args, **kwargs):
"""
Control entrypoint. Setup the base properties for this process (mainly a listener).
"""
if self.name:
threading.current_thread().name = "%s-target" % self.name
# start time
self._start_time = int(get_ion_ts())
# spawn control flow loop
self._ctrl_thread = self.thread_manager.spawn(self._control_flow)
# wait on control flow loop, heartbeating as appropriate
while not self._ctrl_thread.ev_exit.wait(timeout=self._heartbeat_secs):
hbst = self.heartbeat()
if not all(hbst):
log.warn("Heartbeat status for process %s returned %s", self, hbst)
if self._heartbeat_stack is not None:
stack_out = "".join(traceback.format_list(self._heartbeat_stack))
else:
stack_out = "N/A"
#raise PyonHeartbeatError("Heartbeat failed: %s, stacktrace:\n%s" % (hbst, stack_out))
log.warn("Heartbeat failed: %s, stacktrace:\n%s", hbst, stack_out)
# this is almost a no-op as we don't fall out of the above loop without
# exiting the ctrl_thread, but having this line here makes testing much
# easier.
self._ctrl_thread.join()
def _routing_call(self, call, context, *callargs, **callkwargs):
"""
Endpoints call into here to synchronize across the entire IonProcess.
Returns immediately with an AsyncResult that can be waited on. Calls
are made by the loop in _control_flow. We pass in the calling greenlet so
exceptions are raised in the correct context.
@param call The call to be made within this ION processes' calling greenlet.
@param callargs The keyword args to pass to the call.
@param context Optional process-context (usually the headers of the incoming call) to be
set. Process-context is greenlet-local, and since we're crossing greenlet
boundaries, we must set it again in the ION process' calling greenlet.
"""
ar = AsyncResult()
if len(callargs) == 0 and len(callkwargs) == 0:
log.trace("_routing_call got no arguments for the call %s, check your call's parameters", call)
self._ctrl_queue.put((greenlet.getcurrent(), ar, call, callargs, callkwargs, context))
return ar
def has_pending_call(self, ar):
"""
Returns true if the call (keyed by the AsyncResult returned by _routing_call) is still pending.
"""
for _, qar, _, _, _, _ in self._ctrl_queue.queue:
if qar == ar:
return True
return False
def _cancel_pending_call(self, ar):
"""
Cancels a pending call (keyed by the AsyncResult returend by _routing_call).
@return True if the call was truly pending.
"""
if self.has_pending_call(ar):
ar.set(False)
return True
return False
def _interrupt_control_thread(self):
"""
Signal the control flow thread that it needs to abort processing, likely due to a timeout.
"""
self._ctrl_thread.proc.kill(exception=OperationInterruptedException, block=False)
def cancel_or_abort_call(self, ar):
"""
Either cancels a future pending call, or aborts the current processing if the given AR is unset.
The pending call is keyed by the AsyncResult returned by _routing_call.
"""
if not self._cancel_pending_call(ar) and not ar.ready():
self._interrupt_control_thread()
def _control_flow(self):
"""
Main process thread of execution method.
This method is run inside a greenlet and exists for each ION process. Listeners
attached to the process, either RPC Servers or Subscribers, synchronize their calls
by placing future calls into the queue by calling _routing_call. This is all done
automatically for you by the Container's Process Manager.
This method blocks until there are calls to be made in the synchronized queue, and
then calls from within this greenlet. Any exception raised is caught and re-raised
in the greenlet that originally scheduled the call. If successful, the AsyncResult
created at scheduling time is set with the result of the call.
"""
if self.name:
svc_name = "unnamed-service"
if self.service is not None and hasattr(self.service, 'name'):
svc_name = self.service.name
threading.current_thread().name = "%s-%s-ctrl" % (svc_name, self.name)
self._ready_control.set()
for calltuple in self._ctrl_queue:
calling_gl, ar, call, callargs, callkwargs, context = calltuple
log.debug("control_flow making call: %s %s %s (has context: %s)", call, callargs, callkwargs, context is not None)
res = None
start_proc_time = int(get_ion_ts())
# check context for expiration
if context is not None and 'reply-by' in context:
if start_proc_time >= int(context['reply-by']):
log.info("control_flow: attempting to process message already exceeding reply-by, ignore")
# raise a timeout in the calling thread to allow endpoints to continue processing
e = IonTimeout("Reply-by time has already occurred (reply-by: %s, op start time: %s)" % (context['reply-by'], start_proc_time))
calling_gl.kill(exception=e, block=False)
continue
# also check ar if it is set, if it is, that means it is cancelled
if ar.ready():
log.info("control_flow: attempting to process message that has been cancelled, ignore")
continue
try:
with self.service.push_context(context):
with self.service.container.context.push_context(context):
self._ctrl_current = ar
res = call(*callargs, **callkwargs)
except OperationInterruptedException:
# endpoint layer takes care of response as it's the one that caused this
log.debug("Operation interrupted")
pass
except Exception as e:
# raise the exception in the calling greenlet, and don't
# wait for it to die - it's likely not going to do so.
# try decorating the args of the exception with the true traceback
# this should be reported by ThreadManager._child_failed
exc = PyonThreadTraceback("IonProcessThread _control_flow caught an exception (call: %s, *args %s, **kwargs %s, context %s)\nTrue traceback captured by IonProcessThread' _control_flow:\n\n%s" % (call, callargs, callkwargs, context, traceback.format_exc()))
e.args = e.args + (exc,)
# HACK HACK HACK
# we know that we only handle TypeError and IonException derived things, so only forward those if appropriate
if isinstance(e, (TypeError, IonException)):
calling_gl.kill(exception=e, block=False)
else:
# otherwise, swallow/record/report and hopefully we can continue on our way
self._errors.append((call, callargs, callkwargs, context, e, exc))
log.warn(exc)
log.warn("Attempting to continue...")
# have to raise something friendlier on the client side
calling_gl.kill(exception=ContainerError(str(exc)), block=False)
finally:
proc_time = int(get_ion_ts()) - start_proc_time
self._proc_time += proc_time
self._ctrl_current = None
ar.set(res)
def start_listeners(self):
"""
Starts all listeners in managed greenlets.
This must be called after starting this IonProcess. Currently, the Container's ProcManager
will handle this for you, but if using an IonProcess manually, you must remember to call
this method or no attached listeners will run.
"""
try:
# disable normal error reporting, this method should only be called from startup
self.thread_manager._failure_notify_callback = None
# spawn all listeners in startup listeners (from initializer, or added later)
for listener in self._startup_listeners:
self.add_endpoint(listener)
with Timeout(10):
waitall([x.get_ready_event() for x in self.listeners])
except Timeout:
# remove failed endpoints before reporting failure above
for listener, proc in self._listener_map.iteritems():
if proc.proc.dead:
log.info("removed dead listener: %s", listener)
self.listeners.remove(listener)
self.thread_manager.children.remove(proc)
raise IonProcessError("start_listeners did not complete in expected time")
finally:
self.thread_manager._failure_notify_callback = self._child_failed
def _notify_stop(self):
"""
Called when the process is about to be shut down.
Instructs all listeners to close, puts a StopIteration into the synchronized queue,
and waits for the listeners to close and for the control queue to exit.
"""
for listener in self.listeners:
try:
listener.close()
except Exception as ex:
tb = traceback.format_exc()
log.warn("Could not close listener, attempting to ignore: %s\nTraceback:\n%s", ex, tb)
self._ctrl_queue.put(StopIteration)
# wait_children will join them and then get() them, which may raise an exception if any of them
# died with an exception.
self.thread_manager.wait_children(30)
PyonThread._notify_stop(self)
# run the cleanup method if we have one
if self._cleanup_method is not None:
try:
self._cleanup_method(self)
except Exception as ex:
log.warn("Cleanup method error, attempting to ignore: %s\nTraceback: %s", ex, traceback.format_exc())
def get_ready_event(self):
"""
Returns an Event that is set when the control greenlet is up and running.
"""
return self._ready_control
class IonProcessThread(PyonThread):
"""
The control part of an ION process.
"""
def __init__(self, target=None, listeners=None, name=None, service=None, cleanup_method=None,
heartbeat_secs=10, **kwargs):
"""
Constructs the control part of an ION process.
Used by the container's IonProcessThreadManager, as part of spawn_process.
@param target A callable to run in the PyonThread. If None (typical), will use the target method
defined in this class.
@param listeners A list of listening endpoints attached to this thread.
@param name The name of this ION process.
@param service An instance of the BaseService derived class which contains the business logic for
the ION process.
@param cleanup_method An optional callable to run when the process is stopping. Runs after all other
notify_stop calls have run. Should take one param, this instance.
@param heartbeat_secs Number of seconds to wait in between heartbeats.
"""
self._startup_listeners = listeners or []
self.listeners = []
self._listener_map = {}
self.name = name
self.service = service
self._cleanup_method = cleanup_method
self.thread_manager = ThreadManager(failure_notify_callback=self._child_failed) # bubbles up to main thread manager
self._dead_children = [] # save any dead children for forensics
self._ctrl_thread = None
self._ctrl_queue = Queue()
self._ready_control = Event()
self._errors = []
self._ctrl_current = None # set to the AR generated by _routing_call when in the context of a call
# processing vs idle time (ms)
self._start_time = None
self._proc_time = 0 # busy time since start
self._proc_time_prior = 0 # busy time at the beginning of the prior interval
self._proc_time_prior2 = 0 # busy time at the beginning of 2 interval's ago
self._proc_interval_num = 0 # interval num of last record
# for heartbeats, used to detect stuck processes
self._heartbeat_secs = heartbeat_secs # amount of time to wait between heartbeats
self._heartbeat_stack = None # stacktrace of last heartbeat
self._heartbeat_time = None # timestamp of heart beat last matching the current op
self._heartbeat_op = None # last operation (by AR)
self._heartbeat_count = 0 # number of times this operation has been seen consecutively
self._log_call_exception = CFG.get_safe("container.process.log_exceptions", False)
self._log_call_dbstats = CFG.get_safe("container.process.log_dbstats", False)
self._warn_call_dbstmt_threshold = CFG.get_safe("container.process.warn_dbstmt_threshold", 0)
PyonThread.__init__(self, target=target, **kwargs)
def heartbeat(self):
"""
Returns a 3-tuple indicating everything is ok.
Should only be called after the process has been started.
Checks the following:
- All attached endpoints are alive + listening (this means ready)
- The control flow greenlet is alive + listening or processing
@return 3-tuple indicating (listeners ok, ctrl thread ok, heartbeat status). Use all on it for a
boolean indication of success.
"""
listeners_ok = True
for l in self.listeners:
if not (l in self._listener_map and not self._listener_map[l].proc.dead and l.get_ready_event().is_set()):
listeners_ok = False
ctrl_thread_ok = self._ctrl_thread.running
# are we currently processing something?
heartbeat_ok = True
if self._ctrl_current is not None:
st = traceback.extract_stack(self._ctrl_thread.proc.gr_frame)
if self._ctrl_current == self._heartbeat_op:
if st == self._heartbeat_stack:
self._heartbeat_count += 1 # we've seen this before! increment count
# we've been in this for the last X ticks, or it's been X seconds, fail this part of the heartbeat
if self._heartbeat_count > CFG.get_safe('container.timeout.heartbeat_proc_count_threshold', 30) or \
get_ion_ts_millis() - int(self._heartbeat_time) >= CFG.get_safe('container.timeout.heartbeat_proc_time_threshold', 30) * 1000:
heartbeat_ok = False
else:
# it's made some progress
self._heartbeat_count = 1
self._heartbeat_stack = st
self._heartbeat_time = get_ion_ts()
else:
self._heartbeat_op = self._ctrl_current
self._heartbeat_count = 1
self._heartbeat_time = get_ion_ts()
self._heartbeat_stack = st
else:
self._heartbeat_op = None
self._heartbeat_count = 0
#log.debug("%s %s %s", listeners_ok, ctrl_thread_ok, heartbeat_ok)
return (listeners_ok, ctrl_thread_ok, heartbeat_ok)
@property
def time_stats(self):
"""
Returns a 5-tuple of (total time, idle time, processing time, time since prior interval start,
busy since prior interval start), all in ms (int).
"""
now = get_ion_ts_millis()
running_time = now - self._start_time
idle_time = running_time - self._proc_time
cur_interval = now / STAT_INTERVAL_LENGTH
now_since_prior = now - (cur_interval - 1) * STAT_INTERVAL_LENGTH
if cur_interval == self._proc_interval_num:
proc_time_since_prior = self._proc_time-self._proc_time_prior2
elif cur_interval-1 == self._proc_interval_num:
proc_time_since_prior = self._proc_time-self._proc_time_prior
else:
proc_time_since_prior = 0
return (running_time, idle_time, self._proc_time, now_since_prior, proc_time_since_prior)
def _child_failed(self, child):
"""
Callback from gevent as set in the TheadManager, when a child greenlet fails.
Kills the ION process main greenlet. This propagates the error up to the process supervisor.
"""
# remove the child from the list of children (so we can shut down cleanly)
for x in self.thread_manager.children:
if x.proc == child:
self.thread_manager.children.remove(x)
break
self._dead_children.append(child)
# kill this process's main greenlet. This should be noticed by the container's proc manager
self.proc.kill(child.exception)
def add_endpoint(self, listener, activate=True):
"""
Adds a listening endpoint to be managed by this ION process.
Spawns the listen loop and sets the routing call to synchronize incoming messages
here. If this process hasn't been started yet, adds it to the list of listeners
to start on startup.
@param activate If True (default), start consuming from listener
"""
if self.proc:
listener.routing_call = self._routing_call
if self.name:
svc_name = "unnamed-service"
if self.service is not None and hasattr(self.service, 'name'):
svc_name = self.service.name
listen_thread_name = "%s-%s-listen-%s" % (svc_name, self.name, len(self.listeners)+1)
else:
listen_thread_name = "unknown-listener-%s" % (len(self.listeners)+1)
listen_thread = self.thread_manager.spawn(listener.listen, thread_name=listen_thread_name, activate=activate)
listen_thread.proc._glname = "ION Proc listener %s" % listen_thread_name
self._listener_map[listener] = listen_thread
self.listeners.append(listener)
else:
self._startup_listeners.append(listener)
def remove_endpoint(self, listener):
"""
Removes a listening endpoint from management by this ION process.
If the endpoint is unknown to this ION process, raises an error.
@return The PyonThread running the listen loop, if it exists. You are
responsible for closing it when appropriate.
"""
if listener in self.listeners:
self.listeners.remove(listener)
return self._listener_map.pop(listener)
elif listener in self._startup_listeners:
self._startup_listeners.remove(listener)
return None
else:
raise IonProcessError("Cannot remove unrecognized listener: %s" % listener)
def target(self, *args, **kwargs):
"""
Entry point for the main process greenlet.
Setup the base properties for this process (mainly the control thread).
"""
if self.name:
threading.current_thread().name = "%s-target" % self.name
# start time
self._start_time = get_ion_ts_millis()
self._proc_interval_num = self._start_time / STAT_INTERVAL_LENGTH
# spawn control flow loop
self._ctrl_thread = self.thread_manager.spawn(self._control_flow)
self._ctrl_thread.proc._glname = "ION Proc CL %s" % self.name
# wait on control flow loop, heartbeating as appropriate
while not self._ctrl_thread.ev_exit.wait(timeout=self._heartbeat_secs):
hbst = self.heartbeat()
if not all(hbst):
log.warn("Heartbeat status for process %s returned %s", self, hbst)
if self._heartbeat_stack is not None:
stack_out = "".join(traceback.format_list(self._heartbeat_stack))
else:
stack_out = "N/A"
#raise PyonHeartbeatError("Heartbeat failed: %s, stacktrace:\n%s" % (hbst, stack_out))
log.warn("Heartbeat failed: %s, stacktrace:\n%s", hbst, stack_out)
# this is almost a no-op as we don't fall out of the above loop without
# exiting the ctrl_thread, but having this line here makes testing much easier.
self._ctrl_thread.join()
def _routing_call(self, call, context, *callargs, **callkwargs):
"""
Endpoints call into here to synchronize across the entire IonProcess.
Returns immediately with an AsyncResult that can be waited on. Calls
are made by the loop in _control_flow. We pass in the calling greenlet so
exceptions are raised in the correct context.
@param call The call to be made within this ION processes' calling greenlet.
@param callargs The keyword args to pass to the call.
@param context Optional process-context (usually the headers of the incoming call) to be
set. Process-context is greenlet-local, and since we're crossing greenlet
boundaries, we must set it again in the ION process' calling greenlet.
"""
ar = AsyncResult()
if len(callargs) == 0 and len(callkwargs) == 0:
log.trace("_routing_call got no arguments for the call %s, check your call's parameters", call)
self._ctrl_queue.put((greenlet.getcurrent(), ar, call, callargs, callkwargs, context))
return ar
def has_pending_call(self, ar):
"""
Returns true if the call (keyed by the AsyncResult returned by _routing_call) is still pending.
"""
for _, qar, _, _, _, _ in self._ctrl_queue.queue:
if qar == ar:
return True
return False
def _cancel_pending_call(self, ar):
"""
Cancels a pending call (keyed by the AsyncResult returend by _routing_call).
@return True if the call was truly pending.
"""
if self.has_pending_call(ar):
ar.set(False)
return True
return False
def _interrupt_control_thread(self):
"""
Signal the control flow thread that it needs to abort processing, likely due to a timeout.
"""
self._ctrl_thread.proc.kill(exception=OperationInterruptedException, block=False)
def cancel_or_abort_call(self, ar):
"""
Either cancels a future pending call, or aborts the current processing if the given AR is unset.
The pending call is keyed by the AsyncResult returned by _routing_call.
"""
if not self._cancel_pending_call(ar) and not ar.ready():
self._interrupt_control_thread()
def _control_flow(self):
"""
Entry point for process control thread of execution.
This method is run by the control greenlet for each ION process. Listeners attached
to the process, either RPC Servers or Subscribers, synchronize calls to the process
by placing call requests into the queue by calling _routing_call.
This method blocks until there are calls to be made in the synchronized queue, and
then calls from within this greenlet. Any exception raised is caught and re-raised
in the greenlet that originally scheduled the call. If successful, the AsyncResult
created at scheduling time is set with the result of the call.
"""
if self.name:
svc_name = "unnamed-service"
if self.service is not None and hasattr(self.service, 'name'):
svc_name = self.service.name
threading.current_thread().name = "%s-%s" % (svc_name, self.name)
thread_base_name = threading.current_thread().name
self._ready_control.set()
for calltuple in self._ctrl_queue:
calling_gl, ar, call, callargs, callkwargs, context = calltuple
request_id = (context or {}).get("request-id", None)
if request_id:
threading.current_thread().name = thread_base_name + "-" + str(request_id)
#log.debug("control_flow making call: %s %s %s (has context: %s)", call, callargs, callkwargs, context is not None)
res = None
start_proc_time = get_ion_ts_millis()
self._record_proc_time(start_proc_time)
# check context for expiration
if context is not None and 'reply-by' in context:
if start_proc_time >= int(context['reply-by']):
log.info("control_flow: attempting to process message already exceeding reply-by, ignore")
# raise a timeout in the calling thread to allow endpoints to continue processing
e = IonTimeout("Reply-by time has already occurred (reply-by: %s, op start time: %s)" % (context['reply-by'], start_proc_time))
calling_gl.kill(exception=e, block=False)
continue
# If ar is set, means it is cancelled
if ar.ready():
log.info("control_flow: attempting to process message that has been cancelled, ignore")
continue
init_db_stats()
try:
# ******************************************************************
# ****** THIS IS WHERE THE RPC OPERATION/SERVICE CALL IS MADE ******
with self.service.push_context(context):
with self.service.container.context.push_context(context):
self._ctrl_current = ar
res = call(*callargs, **callkwargs)
# ****** END CALL, EXCEPTION HANDLING FOLLOWS ******
# ******************************************************************
except OperationInterruptedException:
# endpoint layer takes care of response as it's the one that caused this
log.debug("Operation interrupted")
pass
except Exception as e:
if self._log_call_exception:
log.exception("PROCESS exception: %s" % e.message)
# Raise the exception in the calling greenlet.
# Try decorating the args of the exception with the true traceback -
# this should be reported by ThreadManager._child_failed
exc = PyonThreadTraceback("IonProcessThread _control_flow caught an exception (call: %s, *args %s, **kwargs %s, context %s)\nTrue traceback captured by IonProcessThread' _control_flow:\n\n%s" % (
call, callargs, callkwargs, context, traceback.format_exc()))
e.args = e.args + (exc,)
# HACK HACK HACK
# we know that we only handle TypeError and IonException derived things, so only forward those if appropriate
if isinstance(e, (TypeError, IonException)):
calling_gl.kill(exception=e, block=False)
else:
# otherwise, swallow/record/report and hopefully we can continue on our way
self._errors.append((call, callargs, callkwargs, context, e, exc))
log.warn(exc)
log.warn("Attempting to continue...")
# have to raise something friendlier on the client side
# calling_gl.kill(exception=ContainerError(str(exc)), block=False)
# If exception string representation then calling calling_gl.kill(exception=ContainerError(str(exc)), block=False)
# will crush the container.
exceptions_str = str(exc)
if len(exceptions_str) > 10000:
exceptions_str = (
"Exception string representation is to large to put it all here. "
"Begin and end of the exception:\n"
+ exceptions_str[:2000] + "\n...\n" + exceptions_str[-2000:]
)
calling_gl.kill(exception=ContainerError(exceptions_str), block=False)
finally:
try:
self._compute_proc_stats(start_proc_time)
db_stats = get_db_stats()
if db_stats:
if self._warn_call_dbstmt_threshold > 0 and db_stats.get("count.all", 0) >= self._warn_call_dbstmt_threshold:
stats_str = ", ".join("{}={}".format(k, db_stats[k]) for k in sorted(db_stats.keys()))
log.warn("PROC_OP '%s.%s' EXCEEDED DB THRESHOLD. stats=%s", call.__module__, call.__name__, stats_str)
elif self._log_call_dbstats:
stats_str = ", ".join("{}={}".format(k, db_stats[k]) for k in sorted(db_stats.keys()))
log.info("PROC_OP '%s.%s' DB STATS: %s", call.__module__, call.__name__, stats_str)
clear_db_stats()
except Exception:
log.exception("Error computing process call stats")
self._ctrl_current = None
threading.current_thread().name = thread_base_name
ar.set(res)
def _record_proc_time(self, cur_time):
""" Keep the _proc_time of the prior and prior-prior intervals for stats computation
"""
cur_interval = cur_time / STAT_INTERVAL_LENGTH
if cur_interval == self._proc_interval_num:
# We're still in the same interval - no update
pass
elif cur_interval-1 == self._proc_interval_num:
# Record the stats from the prior interval
self._proc_interval_num = cur_interval
self._proc_time_prior2 = self._proc_time_prior
self._proc_time_prior = self._proc_time
elif cur_interval-1 > self._proc_interval_num:
# We skipped an entire interval - everything is prior2
self._proc_interval_num = cur_interval
self._proc_time_prior2 = self._proc_time
self._proc_time_prior = self._proc_time
def _compute_proc_stats(self, start_proc_time):
cur_time = get_ion_ts_millis()
self._record_proc_time(cur_time)
proc_time = cur_time - start_proc_time
self._proc_time += proc_time
def start_listeners(self):
"""
Starts all listeners in managed greenlets.
Usually called by the ProcManager, unless using IonProcess manually.
"""
try:
# disable normal error reporting, this method should only be called from startup
self.thread_manager._failure_notify_callback = None
# spawn all listeners in startup listeners (from initializer, or added later)
for listener in self._startup_listeners:
self.add_endpoint(listener)
with Timeout(seconds=CFG.get_safe('container.messaging.timeout.start_listener', 30)):
gevent.wait([x.get_ready_event() for x in self.listeners])
except Timeout:
# remove failed endpoints before reporting failure above
for listener, proc in self._listener_map.iteritems():
if proc.proc.dead:
log.info("removed dead listener: %s", listener)
self.listeners.remove(listener)
self.thread_manager.children.remove(proc)
raise IonProcessError("start_listeners did not complete in expected time")
finally:
self.thread_manager._failure_notify_callback = self._child_failed
def _notify_stop(self):
"""
Called when the process is about to be shut down.
Instructs all listeners to close, puts a StopIteration into the synchronized queue,
and waits for the listeners to close and for the control queue to exit.
"""
for listener in self.listeners:
try:
listener.close()
except Exception as ex:
tb = traceback.format_exc()
log.warn("Could not close listener, attempting to ignore: %s\nTraceback:\n%s", ex, tb)
self._ctrl_queue.put(StopIteration)
# wait_children will join them and then get() them, which may raise an exception if any of them
# died with an exception.
self.thread_manager.wait_children(30)
PyonThread._notify_stop(self)
# run the cleanup method if we have one
if self._cleanup_method is not None:
try:
self._cleanup_method(self)
except Exception as ex:
log.warn("Cleanup method error, attempting to ignore: %s\nTraceback: %s", ex, traceback.format_exc())
def get_ready_event(self):
"""
Returns an Event that is set when the control greenlet is up and running.
"""
return self._ready_control
class IonProcessThread(PyonThread):
"""
Form the base of an ION process.
"""
def __init__(self,
target=None,
listeners=None,
name=None,
service=None,
**kwargs):
self._startup_listeners = listeners or []
self.listeners = []
self.name = name
self.service = service
self.thread_manager = ThreadManager(
failure_notify_callback=self._child_failed
) # bubbles up to main thread manager
self._ctrl_queue = Queue()
PyonThread.__init__(self, target=target, **kwargs)
def _child_failed(self, child):
"""
Occurs when any child greenlet fails.
Propogates the error up to the process supervisor.
"""
self.proc.kill(child.exception)
def add_endpoint(self, listener):
"""
Adds a listening endpoint to this ION process.
Spawns the listen loop and sets the routing call to synchronize incoming messages
here. If this process hasn't been started yet, adds it to the list of listeners
to start on startup.
"""
if self.proc:
listener.routing_call = self._routing_call
self.thread_manager.spawn(listener.listen)
self.listeners.append(listener)
else:
self._startup_listeners.append(listener)
def target(self, *args, **kwargs):
"""
Control entrypoint. Setup the base properties for this process (mainly a listener).
"""
if self.name:
threading.current_thread().name = self.name
# spawn all listeners in startup listeners (from initializer, or added later)
for listener in self._startup_listeners:
self.add_endpoint(listener)
# spawn control flow loop
ct = self.thread_manager.spawn(self._control_flow)
# wait on control flow loop!
ct.get()
def _routing_call(self, call, callargs, context=None):
"""
Endpoints call into here to synchronize across the entire IonProcess.
Returns immediately with an AsyncResult that can be waited on. Calls
are made by the loop in _control_flow. We pass in the calling greenlet so
exceptions are raised in the correct context.
@param call The call to be made within this ION processes' calling greenlet.
@param callargs The keyword args to pass to the call.
@param context Optional process-context (usually the headers of the incoming call) to be
set. Process-context is greenlet-local, and since we're crossing greenlet
boundaries, we must set it again in the ION process' calling greenlet.
"""
ar = AsyncResult()
self._ctrl_queue.put(
(greenlet.getcurrent(), ar, call, callargs, context))
return ar
def _control_flow(self):
"""
Main process thread of execution method.
This method is run inside a greenlet and exists for each ION process. Listeners
attached to the process, either RPC Servers or Subscribers, synchronize their calls
by placing future calls into the queue by calling _routing_call. This is all done
automatically for you by the Container's Process Manager.
This method blocks until there are calls to be made in the synchronized queue, and
then calls from within this greenlet. Any exception raised is caught and re-raised
in the greenlet that originally scheduled the call. If successful, the AsyncResult
created at scheduling time is set with the result of the call.
"""
for calltuple in self._ctrl_queue:
calling_gl, ar, call, callargs, context = calltuple
log.debug("control_flow making call: %s %s (has context: %s)",
call, callargs, context is not None)
res = None
try:
with self.service.push_context(context):
res = call(**callargs)
except Exception as e:
# raise the exception in the calling greenlet, and don't
# wait for it to die - it's likely not going to do so.
# try decorating the args of the exception with the true traceback
# this should be reported by ThreadManager._child_failed
exc = PyonThreadTraceback(
"True traceback captured by IonProcessThread' _control_flow:\n\n"
+ traceback.format_exc())
e.args = e.args + (exc, )
calling_gl.kill(exception=e, block=False)
ar.set(res)
def _notify_stop(self):
"""
Called when the process is about to be shut down.
Instructs all listeners to close, puts a StopIteration into the synchronized queue,
and waits for the listeners to close and for the control queue to exit.
"""
map(lambda x: x.close(), self.listeners)
self._ctrl_queue.put(StopIteration)
# wait_children will join them and then get() them, which may raise an exception if any of them
# died with an exception.
self.thread_manager.wait_children(30)
PyonThread._notify_stop(self)
def get_ready_event(self):
"""
Returns an Event that is set when all the listeners in this Process are running.
"""
ev = Event()
def allready(ev):
waitall([x.get_ready_event() for x in self.listeners])
ev.set()
spawn(allready, ev)
return ev
class IonProcessThread(PyonThread):
"""
Form the base of an ION process.
"""
def __init__(self,
target=None,
listeners=None,
name=None,
service=None,
cleanup_method=None,
heartbeat_secs=10,
**kwargs):
"""
Constructs an ION process.
You don't create one of these directly, the IonProcessThreadManager run by a container does this for
you via the ProcManager interface. Call the container's spawn_process method and this method will run.
@param target A callable to run in the PyonThread. If None (typical), will use the target method
defined in this class.
@param listeners A list of listening endpoints attached to this thread.
@param name The name of this ION process.
@param service An instance of the BaseService derived class which contains the business logic for
an ION process.
@param cleanup_method An optional callable to run when the process is stopping. Runs after all other
notify_stop calls have run. Should take one param, this instance.
@param heartbeat_secs Number of seconds to wait in between heartbeats.
"""
self._startup_listeners = listeners or []
self.listeners = []
self._listener_map = {}
self.name = name
self.service = service
self._cleanup_method = cleanup_method
self.thread_manager = ThreadManager(
failure_notify_callback=self._child_failed
) # bubbles up to main thread manager
self._dead_children = [] # save any dead children for forensics
self._ctrl_thread = None
self._ctrl_queue = Queue()
self._ready_control = Event()
self._errors = []
self._ctrl_current = None # set to the AR generated by _routing_call when in the context of a call
# processing vs idle time (ms)
self._start_time = None
self._proc_time = 0
# for heartbeats, used to detect stuck processes
self._heartbeat_secs = heartbeat_secs # amount of time to wait between heartbeats
self._heartbeat_stack = None # stacktrace of last heartbeat
self._heartbeat_time = None # timestamp of heart beat last matching the current op
self._heartbeat_op = None # last operation (by AR)
self._heartbeat_count = 0 # number of times this operation has been seen consecutively
PyonThread.__init__(self, target=target, **kwargs)
def heartbeat(self):
"""
Returns a tuple indicating everything is ok.
Should only be called after the process has been started.
Checks the following:
- All attached endpoints are alive + listening
- The control flow greenlet is alive + listening or processing
@return 3-tuple indicating (listeners ok, ctrl thread ok, heartbeat status). Use all on it for a
boolean indication of success.
"""
listeners_ok = True
for l in self.listeners:
if not (l in self._listener_map
and not self._listener_map[l].proc.dead):
listeners_ok = False
ctrl_thread_ok = self._ctrl_thread.running
# are we currently processing something?
heartbeat_ok = True
if self._ctrl_current is not None:
st = traceback.extract_stack(self._ctrl_thread.proc.gr_frame)
if self._ctrl_current == self._heartbeat_op:
if st == self._heartbeat_stack:
self._heartbeat_count += 1 # we've seen this before! increment count
# we've been in this for the last X ticks, or it's been X seconds, fail this part of the heartbeat
if self._heartbeat_count > CFG.get_safe('cc.timeout.heartbeat_proc_count_threshold', 30) or \
int(get_ion_ts()) - int(self._heartbeat_time) >= CFG.get_safe('cc.timeout.heartbeat_proc_time_threshold', 30) * 1000:
heartbeat_ok = False
else:
# it's made some progress
self._heartbeat_count = 1
self._heartbeat_stack = st
self._heartbeat_time = get_ion_ts()
else:
self._heartbeat_op = self._ctrl_current
self._heartbeat_count = 1
self._heartbeat_time = get_ion_ts()
self._heartbeat_stack = st
else:
self._heartbeat_op = None
self._heartbeat_count = 0
return (listeners_ok, ctrl_thread_ok, heartbeat_ok)
@property
def time_stats(self):
"""
Returns a 3-tuple of (total time, idle time, processing time), all in ms.
"""
now = int(get_ion_ts())
running_time = now - self._start_time
idle_time = running_time - self._proc_time
return (running_time, idle_time, self._proc_time)
def _child_failed(self, child):
"""
Occurs when any child greenlet fails.
Propogates the error up to the process supervisor.
"""
# remove the child from the list of children (so we can shut down cleanly)
for x in self.thread_manager.children:
if x.proc == child:
self.thread_manager.children.remove(x)
break
self._dead_children.append(child)
# kill this main, we should be noticed by the container's proc manager
self.proc.kill(child.exception)
def add_endpoint(self, listener):
"""
Adds a listening endpoint to this ION process.
Spawns the listen loop and sets the routing call to synchronize incoming messages
here. If this process hasn't been started yet, adds it to the list of listeners
to start on startup.
"""
if self.proc:
listener.routing_call = self._routing_call
if self.name:
svc_name = "unnamed-service"
if self.service is not None and hasattr(self.service, 'name'):
svc_name = self.service.name
listen_thread_name = "%s-%s-listen-%s" % (
svc_name, self.name, len(self.listeners) + 1)
else:
listen_thread_name = "unknown-listener-%s" % (
len(self.listeners) + 1)
self._listener_map[listener] = self.thread_manager.spawn(
listener.listen, thread_name=listen_thread_name)
self.listeners.append(listener)
else:
self._startup_listeners.append(listener)
def target(self, *args, **kwargs):
"""
Control entrypoint. Setup the base properties for this process (mainly a listener).
"""
if self.name:
threading.current_thread().name = "%s-target" % self.name
# start time
self._start_time = int(get_ion_ts())
# spawn control flow loop
self._ctrl_thread = self.thread_manager.spawn(self._control_flow)
# wait on control flow loop, heartbeating as appropriate
while not self._ctrl_thread.ev_exit.wait(timeout=self._heartbeat_secs):
hbst = self.heartbeat()
if not all(hbst):
log.warn("Heartbeat status for process %s returned %s", self,
hbst)
if self._heartbeat_stack is not None:
stack_out = "".join(
traceback.format_list(self._heartbeat_stack))
else:
stack_out = "N/A"
#raise PyonHeartbeatError("Heartbeat failed: %s, stacktrace:\n%s" % (hbst, stack_out))
log.warn("Heartbeat failed: %s, stacktrace:\n%s", hbst,
stack_out)
# this is almost a no-op as we don't fall out of the above loop without
# exiting the ctrl_thread, but having this line here makes testing much
# easier.
self._ctrl_thread.join()
def _routing_call(self, call, context, *callargs, **callkwargs):
"""
Endpoints call into here to synchronize across the entire IonProcess.
Returns immediately with an AsyncResult that can be waited on. Calls
are made by the loop in _control_flow. We pass in the calling greenlet so
exceptions are raised in the correct context.
@param call The call to be made within this ION processes' calling greenlet.
@param callargs The keyword args to pass to the call.
@param context Optional process-context (usually the headers of the incoming call) to be
set. Process-context is greenlet-local, and since we're crossing greenlet
boundaries, we must set it again in the ION process' calling greenlet.
"""
ar = AsyncResult()
if len(callargs) == 0 and len(callkwargs) == 0:
log.trace(
"_routing_call got no arguments for the call %s, check your call's parameters",
call)
self._ctrl_queue.put(
(greenlet.getcurrent(), ar, call, callargs, callkwargs, context))
return ar
def has_pending_call(self, ar):
"""
Returns true if the call (keyed by the AsyncResult returned by _routing_call) is still pending.
"""
for _, qar, _, _, _, _ in self._ctrl_queue.queue:
if qar == ar:
return True
return False
def _cancel_pending_call(self, ar):
"""
Cancels a pending call (keyed by the AsyncResult returend by _routing_call).
@return True if the call was truly pending.
"""
if self.has_pending_call(ar):
ar.set(False)
return True
return False
def _interrupt_control_thread(self):
"""
Signal the control flow thread that it needs to abort processing, likely due to a timeout.
"""
self._ctrl_thread.proc.kill(exception=OperationInterruptedException,
block=False)
def cancel_or_abort_call(self, ar):
"""
Either cancels a future pending call, or aborts the current processing if the given AR is unset.
The pending call is keyed by the AsyncResult returned by _routing_call.
"""
if not self._cancel_pending_call(ar) and not ar.ready():
self._interrupt_control_thread()
def _control_flow(self):
"""
Main process thread of execution method.
This method is run inside a greenlet and exists for each ION process. Listeners
attached to the process, either RPC Servers or Subscribers, synchronize their calls
by placing future calls into the queue by calling _routing_call. This is all done
automatically for you by the Container's Process Manager.
This method blocks until there are calls to be made in the synchronized queue, and
then calls from within this greenlet. Any exception raised is caught and re-raised
in the greenlet that originally scheduled the call. If successful, the AsyncResult
created at scheduling time is set with the result of the call.
"""
if self.name:
svc_name = "unnamed-service"
if self.service is not None and hasattr(self.service, 'name'):
svc_name = self.service.name
threading.current_thread().name = "%s-%s-ctrl" % (svc_name,
self.name)
self._ready_control.set()
for calltuple in self._ctrl_queue:
calling_gl, ar, call, callargs, callkwargs, context = calltuple
log.debug("control_flow making call: %s %s %s (has context: %s)",
call, callargs, callkwargs, context is not None)
res = None
start_proc_time = int(get_ion_ts())
# check context for expiration
if context is not None and 'reply-by' in context:
if start_proc_time >= int(context['reply-by']):
log.info(
"control_flow: attempting to process message already exceeding reply-by, ignore"
)
# raise a timeout in the calling thread to allow endpoints to continue processing
e = IonTimeout(
"Reply-by time has already occurred (reply-by: %s, op start time: %s)"
% (context['reply-by'], start_proc_time))
calling_gl.kill(exception=e, block=False)
continue
# also check ar if it is set, if it is, that means it is cancelled
if ar.ready():
log.info(
"control_flow: attempting to process message that has been cancelled, ignore"
)
continue
try:
with self.service.push_context(context):
with self.service.container.context.push_context(context):
self._ctrl_current = ar
res = call(*callargs, **callkwargs)
except OperationInterruptedException:
# endpoint layer takes care of response as it's the one that caused this
log.debug("Operation interrupted")
pass
except Exception as e:
# raise the exception in the calling greenlet, and don't
# wait for it to die - it's likely not going to do so.
# try decorating the args of the exception with the true traceback
# this should be reported by ThreadManager._child_failed
exc = PyonThreadTraceback(
"IonProcessThread _control_flow caught an exception (call: %s, *args %s, **kwargs %s, context %s)\nTrue traceback captured by IonProcessThread' _control_flow:\n\n%s"
% (call, callargs, callkwargs, context,
traceback.format_exc()))
e.args = e.args + (exc, )
# HACK HACK HACK
# we know that we only handle TypeError and IonException derived things, so only forward those if appropriate
if isinstance(e, (TypeError, IonException)):
calling_gl.kill(exception=e, block=False)
else:
# otherwise, swallow/record/report and hopefully we can continue on our way
self._errors.append(
(call, callargs, callkwargs, context, e, exc))
log.warn(exc)
log.warn("Attempting to continue...")
# have to raise something friendlier on the client side
calling_gl.kill(exception=ContainerError(str(exc)),
block=False)
finally:
proc_time = int(get_ion_ts()) - start_proc_time
self._proc_time += proc_time
self._ctrl_current = None
ar.set(res)
def start_listeners(self):
"""
Starts all listeners in managed greenlets.
This must be called after starting this IonProcess. Currently, the Container's ProcManager
will handle this for you, but if using an IonProcess manually, you must remember to call
this method or no attached listeners will run.
"""
try:
# disable normal error reporting, this method should only be called from startup
self.thread_manager._failure_notify_callback = None
# spawn all listeners in startup listeners (from initializer, or added later)
for listener in self._startup_listeners:
self.add_endpoint(listener)
with Timeout(10):
waitall([x.get_ready_event() for x in self.listeners])
except Timeout:
# remove failed endpoints before reporting failure above
for listener, proc in self._listener_map.iteritems():
if proc.proc.dead:
log.info("removed dead listener: %s", listener)
self.listeners.remove(listener)
self.thread_manager.children.remove(proc)
raise IonProcessError(
"start_listeners did not complete in expected time")
finally:
self.thread_manager._failure_notify_callback = self._child_failed
def _notify_stop(self):
"""
Called when the process is about to be shut down.
Instructs all listeners to close, puts a StopIteration into the synchronized queue,
and waits for the listeners to close and for the control queue to exit.
"""
for listener in self.listeners:
try:
listener.close()
except Exception as ex:
tb = traceback.format_exc()
log.warn(
"Could not close listener, attempting to ignore: %s\nTraceback:\n%s",
ex, tb)
self._ctrl_queue.put(StopIteration)
# wait_children will join them and then get() them, which may raise an exception if any of them
# died with an exception.
self.thread_manager.wait_children(30)
PyonThread._notify_stop(self)
# run the cleanup method if we have one
if self._cleanup_method is not None:
try:
self._cleanup_method(self)
except Exception as ex:
log.warn(
"Cleanup method error, attempting to ignore: %s\nTraceback: %s",
ex, traceback.format_exc())
def get_ready_event(self):
"""
Returns an Event that is set when the control greenlet is up and running.
"""
return self._ready_control
def __init__(self,
target=None,
listeners=None,
name=None,
service=None,
cleanup_method=None,
heartbeat_secs=10,
**kwargs):
"""
Constructs the control part of an ION process.
Used by the container's IonProcessThreadManager, as part of spawn_process.
@param target A callable to run in the PyonThread. If None (typical), will use the target method
defined in this class.
@param listeners A list of listening endpoints attached to this thread.
@param name The name of this ION process.
@param service An instance of the BaseService derived class which contains the business logic for
the ION process.
@param cleanup_method An optional callable to run when the process is stopping. Runs after all other
notify_stop calls have run. Should take one param, this instance.
@param heartbeat_secs Number of seconds to wait in between heartbeats.
"""
self._startup_listeners = listeners or []
self.listeners = []
self._listener_map = {}
self.name = name
self.service = service
self._cleanup_method = cleanup_method
self.thread_manager = ThreadManager(
failure_notify_callback=self._child_failed
) # bubbles up to main thread manager
self._dead_children = [] # save any dead children for forensics
self._ctrl_thread = None
self._ctrl_queue = Queue()
self._ready_control = Event()
self._errors = []
self._ctrl_current = None # set to the AR generated by _routing_call when in the context of a call
# processing vs idle time (ms)
self._start_time = None
self._proc_time = 0 # busy time since start
self._proc_time_prior = 0 # busy time at the beginning of the prior interval
self._proc_time_prior2 = 0 # busy time at the beginning of 2 interval's ago
self._proc_interval_num = 0 # interval num of last record
# for heartbeats, used to detect stuck processes
self._heartbeat_secs = heartbeat_secs # amount of time to wait between heartbeats
self._heartbeat_stack = None # stacktrace of last heartbeat
self._heartbeat_time = None # timestamp of heart beat last matching the current op
self._heartbeat_op = None # last operation (by AR)
self._heartbeat_count = 0 # number of times this operation has been seen consecutively
self._log_call_exception = CFG.get_safe(
"container.process.log_exceptions", False)
self._log_call_dbstats = CFG.get_safe("container.process.log_dbstats",
False)
self._warn_call_dbstmt_threshold = CFG.get_safe(
"container.process.warn_dbstmt_threshold", 0)
PyonThread.__init__(self, target=target, **kwargs)
class IonProcessThread(PyonThread):
"""
The control part of an ION process.
"""
def __init__(self,
target=None,
listeners=None,
name=None,
service=None,
cleanup_method=None,
heartbeat_secs=10,
**kwargs):
"""
Constructs the control part of an ION process.
Used by the container's IonProcessThreadManager, as part of spawn_process.
@param target A callable to run in the PyonThread. If None (typical), will use the target method
defined in this class.
@param listeners A list of listening endpoints attached to this thread.
@param name The name of this ION process.
@param service An instance of the BaseService derived class which contains the business logic for
the ION process.
@param cleanup_method An optional callable to run when the process is stopping. Runs after all other
notify_stop calls have run. Should take one param, this instance.
@param heartbeat_secs Number of seconds to wait in between heartbeats.
"""
self._startup_listeners = listeners or []
self.listeners = []
self._listener_map = {}
self.name = name
self.service = service
self._cleanup_method = cleanup_method
self.thread_manager = ThreadManager(
failure_notify_callback=self._child_failed
) # bubbles up to main thread manager
self._dead_children = [] # save any dead children for forensics
self._ctrl_thread = None
self._ctrl_queue = Queue()
self._ready_control = Event()
self._errors = []
self._ctrl_current = None # set to the AR generated by _routing_call when in the context of a call
# processing vs idle time (ms)
self._start_time = None
self._proc_time = 0 # busy time since start
self._proc_time_prior = 0 # busy time at the beginning of the prior interval
self._proc_time_prior2 = 0 # busy time at the beginning of 2 interval's ago
self._proc_interval_num = 0 # interval num of last record
# for heartbeats, used to detect stuck processes
self._heartbeat_secs = heartbeat_secs # amount of time to wait between heartbeats
self._heartbeat_stack = None # stacktrace of last heartbeat
self._heartbeat_time = None # timestamp of heart beat last matching the current op
self._heartbeat_op = None # last operation (by AR)
self._heartbeat_count = 0 # number of times this operation has been seen consecutively
self._log_call_exception = CFG.get_safe(
"container.process.log_exceptions", False)
self._log_call_dbstats = CFG.get_safe("container.process.log_dbstats",
False)
self._warn_call_dbstmt_threshold = CFG.get_safe(
"container.process.warn_dbstmt_threshold", 0)
PyonThread.__init__(self, target=target, **kwargs)
def heartbeat(self):
"""
Returns a 3-tuple indicating everything is ok.
Should only be called after the process has been started.
Checks the following:
- All attached endpoints are alive + listening (this means ready)
- The control flow greenlet is alive + listening or processing
@return 3-tuple indicating (listeners ok, ctrl thread ok, heartbeat status). Use all on it for a
boolean indication of success.
"""
listeners_ok = True
for l in self.listeners:
if not (l in self._listener_map
and not self._listener_map[l].proc.dead
and l.get_ready_event().is_set()):
listeners_ok = False
ctrl_thread_ok = self._ctrl_thread.running
# are we currently processing something?
heartbeat_ok = True
if self._ctrl_current is not None:
st = traceback.extract_stack(self._ctrl_thread.proc.gr_frame)
if self._ctrl_current == self._heartbeat_op:
if st == self._heartbeat_stack:
self._heartbeat_count += 1 # we've seen this before! increment count
# we've been in this for the last X ticks, or it's been X seconds, fail this part of the heartbeat
if self._heartbeat_count > CFG.get_safe('container.timeout.heartbeat_proc_count_threshold', 30) or \
get_ion_ts_millis() - int(self._heartbeat_time) >= CFG.get_safe('container.timeout.heartbeat_proc_time_threshold', 30) * 1000:
heartbeat_ok = False
else:
# it's made some progress
self._heartbeat_count = 1
self._heartbeat_stack = st
self._heartbeat_time = get_ion_ts()
else:
self._heartbeat_op = self._ctrl_current
self._heartbeat_count = 1
self._heartbeat_time = get_ion_ts()
self._heartbeat_stack = st
else:
self._heartbeat_op = None
self._heartbeat_count = 0
#log.debug("%s %s %s", listeners_ok, ctrl_thread_ok, heartbeat_ok)
return (listeners_ok, ctrl_thread_ok, heartbeat_ok)
@property
def time_stats(self):
"""
Returns a 5-tuple of (total time, idle time, processing time, time since prior interval start,
busy since prior interval start), all in ms (int).
"""
now = get_ion_ts_millis()
running_time = now - self._start_time
idle_time = running_time - self._proc_time
cur_interval = now / STAT_INTERVAL_LENGTH
now_since_prior = now - (cur_interval - 1) * STAT_INTERVAL_LENGTH
if cur_interval == self._proc_interval_num:
proc_time_since_prior = self._proc_time - self._proc_time_prior2
elif cur_interval - 1 == self._proc_interval_num:
proc_time_since_prior = self._proc_time - self._proc_time_prior
else:
proc_time_since_prior = 0
return (running_time, idle_time, self._proc_time, now_since_prior,
proc_time_since_prior)
def _child_failed(self, child):
"""
Callback from gevent as set in the TheadManager, when a child greenlet fails.
Kills the ION process main greenlet. This propagates the error up to the process supervisor.
"""
# remove the child from the list of children (so we can shut down cleanly)
for x in self.thread_manager.children:
if x.proc == child:
self.thread_manager.children.remove(x)
break
self._dead_children.append(child)
# kill this process's main greenlet. This should be noticed by the container's proc manager
self.proc.kill(child.exception)
def add_endpoint(self, listener, activate=True):
"""
Adds a listening endpoint to be managed by this ION process.
Spawns the listen loop and sets the routing call to synchronize incoming messages
here. If this process hasn't been started yet, adds it to the list of listeners
to start on startup.
@param activate If True (default), start consuming from listener
"""
if self.proc:
listener.routing_call = self._routing_call
if self.name:
svc_name = "unnamed-service"
if self.service is not None and hasattr(self.service, 'name'):
svc_name = self.service.name
listen_thread_name = "%s-%s-listen-%s" % (
svc_name, self.name, len(self.listeners) + 1)
else:
listen_thread_name = "unknown-listener-%s" % (
len(self.listeners) + 1)
listen_thread = self.thread_manager.spawn(
listener.listen,
thread_name=listen_thread_name,
activate=activate)
listen_thread.proc._glname = "ION Proc listener %s" % listen_thread_name
self._listener_map[listener] = listen_thread
self.listeners.append(listener)
else:
self._startup_listeners.append(listener)
def remove_endpoint(self, listener):
"""
Removes a listening endpoint from management by this ION process.
If the endpoint is unknown to this ION process, raises an error.
@return The PyonThread running the listen loop, if it exists. You are
responsible for closing it when appropriate.
"""
if listener in self.listeners:
self.listeners.remove(listener)
return self._listener_map.pop(listener)
elif listener in self._startup_listeners:
self._startup_listeners.remove(listener)
return None
else:
raise IonProcessError("Cannot remove unrecognized listener: %s" %
listener)
def target(self, *args, **kwargs):
"""
Entry point for the main process greenlet.
Setup the base properties for this process (mainly the control thread).
"""
if self.name:
threading.current_thread().name = "%s-target" % self.name
# start time
self._start_time = get_ion_ts_millis()
self._proc_interval_num = self._start_time / STAT_INTERVAL_LENGTH
# spawn control flow loop
self._ctrl_thread = self.thread_manager.spawn(self._control_flow)
self._ctrl_thread.proc._glname = "ION Proc CL %s" % self.name
# wait on control flow loop, heartbeating as appropriate
while not self._ctrl_thread.ev_exit.wait(timeout=self._heartbeat_secs):
hbst = self.heartbeat()
if not all(hbst):
log.warn("Heartbeat status for process %s returned %s", self,
hbst)
if self._heartbeat_stack is not None:
stack_out = "".join(
traceback.format_list(self._heartbeat_stack))
else:
stack_out = "N/A"
#raise PyonHeartbeatError("Heartbeat failed: %s, stacktrace:\n%s" % (hbst, stack_out))
log.warn("Heartbeat failed: %s, stacktrace:\n%s", hbst,
stack_out)
# this is almost a no-op as we don't fall out of the above loop without
# exiting the ctrl_thread, but having this line here makes testing much easier.
self._ctrl_thread.join()
def _routing_call(self, call, context, *callargs, **callkwargs):
"""
Endpoints call into here to synchronize across the entire IonProcess.
Returns immediately with an AsyncResult that can be waited on. Calls
are made by the loop in _control_flow. We pass in the calling greenlet so
exceptions are raised in the correct context.
@param call The call to be made within this ION processes' calling greenlet.
@param callargs The keyword args to pass to the call.
@param context Optional process-context (usually the headers of the incoming call) to be
set. Process-context is greenlet-local, and since we're crossing greenlet
boundaries, we must set it again in the ION process' calling greenlet.
"""
ar = AsyncResult()
if len(callargs) == 0 and len(callkwargs) == 0:
log.trace(
"_routing_call got no arguments for the call %s, check your call's parameters",
call)
self._ctrl_queue.put(
(greenlet.getcurrent(), ar, call, callargs, callkwargs, context))
return ar
def has_pending_call(self, ar):
"""
Returns true if the call (keyed by the AsyncResult returned by _routing_call) is still pending.
"""
for _, qar, _, _, _, _ in self._ctrl_queue.queue:
if qar == ar:
return True
return False
def _cancel_pending_call(self, ar):
"""
Cancels a pending call (keyed by the AsyncResult returend by _routing_call).
@return True if the call was truly pending.
"""
if self.has_pending_call(ar):
ar.set(False)
return True
return False
def _interrupt_control_thread(self):
"""
Signal the control flow thread that it needs to abort processing, likely due to a timeout.
"""
self._ctrl_thread.proc.kill(exception=OperationInterruptedException,
block=False)
def cancel_or_abort_call(self, ar):
"""
Either cancels a future pending call, or aborts the current processing if the given AR is unset.
The pending call is keyed by the AsyncResult returned by _routing_call.
"""
if not self._cancel_pending_call(ar) and not ar.ready():
self._interrupt_control_thread()
def _control_flow(self):
"""
Entry point for process control thread of execution.
This method is run by the control greenlet for each ION process. Listeners attached
to the process, either RPC Servers or Subscribers, synchronize calls to the process
by placing call requests into the queue by calling _routing_call.
This method blocks until there are calls to be made in the synchronized queue, and
then calls from within this greenlet. Any exception raised is caught and re-raised
in the greenlet that originally scheduled the call. If successful, the AsyncResult
created at scheduling time is set with the result of the call.
"""
svc_name = getattr(
self.service, "name",
"unnamed-service") if self.service else "unnamed-service"
proc_id = getattr(self.service, "id",
"unknown-pid") if self.service else "unknown-pid"
if self.name:
threading.current_thread().name = "%s-%s" % (svc_name, self.name)
thread_base_name = threading.current_thread().name
self._ready_control.set()
for calltuple in self._ctrl_queue:
calling_gl, ar, call, callargs, callkwargs, context = calltuple
request_id = (context or {}).get("request-id", None)
if request_id:
threading.current_thread(
).name = thread_base_name + "-" + str(request_id)
#log.debug("control_flow making call: %s %s %s (has context: %s)", call, callargs, callkwargs, context is not None)
res = None
start_proc_time = get_ion_ts_millis()
self._record_proc_time(start_proc_time)
# check context for expiration
if context is not None and 'reply-by' in context:
if start_proc_time >= int(context['reply-by']):
log.info(
"control_flow: attempting to process message already exceeding reply-by, ignore"
)
# raise a timeout in the calling thread to allow endpoints to continue processing
e = IonTimeout(
"Reply-by time has already occurred (reply-by: %s, op start time: %s)"
% (context['reply-by'], start_proc_time))
calling_gl.kill(exception=e, block=False)
continue
# If ar is set, means it is cancelled
if ar.ready():
log.info(
"control_flow: attempting to process message that has been cancelled, ignore"
)
continue
init_db_stats()
try:
# ******************************************************************
# ****** THIS IS WHERE THE RPC OPERATION/SERVICE CALL IS MADE ******
with self.service.push_context(context), \
self.service.container.context.push_context(context):
self._ctrl_current = ar
res = call(*callargs, **callkwargs)
# ****** END CALL, EXCEPTION HANDLING FOLLOWS ******
# ******************************************************************
except OperationInterruptedException:
# endpoint layer takes care of response as it's the one that caused this
log.debug("Operation interrupted")
pass
except Exception as e:
if self._log_call_exception:
log.exception("PROCESS exception: %s" % e.message)
# Raise the exception in the calling greenlet.
# Try decorating the args of the exception with the true traceback -
# this should be reported by ThreadManager._child_failed
exc = PyonThreadTraceback(
"IonProcessThread _control_flow caught an exception "
"(call: %s, *args %s, **kwargs %s, context %s)\n"
"True traceback captured by IonProcessThread' _control_flow:\n\n%s"
% (call, callargs, callkwargs, context,
traceback.format_exc()))
e.args = e.args + (exc, )
if isinstance(e, (TypeError, IonException)):
# Pass through known process exceptions, in particular IonException
calling_gl.kill(exception=e, block=False)
else:
# Otherwise, wrap unknown, forward and hopefully we can continue on our way
self._errors.append(
(call, callargs, callkwargs, context, e, exc))
log.warn(exc)
log.warn("Attempting to continue...")
# Note: Too large exception string will crash the container (when passed on as msg header).
exception_str = str(exc)
if len(exception_str) > 10000:
exception_str = (
"Exception string representation too large. "
"Begin and end of the exception:\n" +
exception_str[:2000] + "\n...\n" +
exception_str[-2000:])
calling_gl.kill(exception=ContainerError(exception_str),
block=False)
finally:
try:
# Compute statistics
self._compute_proc_stats(start_proc_time)
db_stats = get_db_stats()
if db_stats:
if self._warn_call_dbstmt_threshold > 0 and db_stats.get(
"count.all",
0) >= self._warn_call_dbstmt_threshold:
stats_str = ", ".join(
"{}={}".format(k, db_stats[k])
for k in sorted(db_stats.keys()))
log.warn(
"PROC_OP '%s.%s' EXCEEDED DB THRESHOLD. stats=%s",
svc_name, call.__name__, stats_str)
elif self._log_call_dbstats:
stats_str = ", ".join(
"{}={}".format(k, db_stats[k])
for k in sorted(db_stats.keys()))
log.info("PROC_OP '%s.%s' DB STATS: %s", svc_name,
call.__name__, stats_str)
clear_db_stats()
if stats_callback:
stats_callback(proc_id=proc_id,
proc_name=self.name,
svc=svc_name,
op=call.__name__,
request_id=request_id,
context=context,
db_stats=db_stats,
proc_stats=self.time_stats,
result=res,
exc=None)
except Exception:
log.exception("Error computing process call stats")
self._ctrl_current = None
threading.current_thread().name = thread_base_name
# Set response in AsyncEvent of caller (endpoint greenlet)
ar.set(res)
def _record_proc_time(self, cur_time):
""" Keep the _proc_time of the prior and prior-prior intervals for stats computation
"""
cur_interval = cur_time / STAT_INTERVAL_LENGTH
if cur_interval == self._proc_interval_num:
# We're still in the same interval - no update
pass
elif cur_interval - 1 == self._proc_interval_num:
# Record the stats from the prior interval
self._proc_interval_num = cur_interval
self._proc_time_prior2 = self._proc_time_prior
self._proc_time_prior = self._proc_time
elif cur_interval - 1 > self._proc_interval_num:
# We skipped an entire interval - everything is prior2
self._proc_interval_num = cur_interval
self._proc_time_prior2 = self._proc_time
self._proc_time_prior = self._proc_time
def _compute_proc_stats(self, start_proc_time):
cur_time = get_ion_ts_millis()
self._record_proc_time(cur_time)
proc_time = cur_time - start_proc_time
self._proc_time += proc_time
def start_listeners(self):
"""
Starts all listeners in managed greenlets.
Usually called by the ProcManager, unless using IonProcess manually.
"""
try:
# disable normal error reporting, this method should only be called from startup
self.thread_manager._failure_notify_callback = None
# spawn all listeners in startup listeners (from initializer, or added later)
for listener in self._startup_listeners:
self.add_endpoint(listener)
with Timeout(seconds=CFG.get_safe(
'container.messaging.timeout.start_listener', 30)):
gevent.wait([x.get_ready_event() for x in self.listeners])
except Timeout:
# remove failed endpoints before reporting failure above
for listener, proc in self._listener_map.iteritems():
if proc.proc.dead:
log.info("removed dead listener: %s", listener)
self.listeners.remove(listener)
self.thread_manager.children.remove(proc)
raise IonProcessError(
"start_listeners did not complete in expected time")
finally:
self.thread_manager._failure_notify_callback = self._child_failed
def _notify_stop(self):
"""
Called when the process is about to be shut down.
Instructs all listeners to close, puts a StopIteration into the synchronized queue,
and waits for the listeners to close and for the control queue to exit.
"""
for listener in self.listeners:
try:
listener.close()
except Exception as ex:
tb = traceback.format_exc()
log.warn(
"Could not close listener, attempting to ignore: %s\nTraceback:\n%s",
ex, tb)
self._ctrl_queue.put(StopIteration)
# wait_children will join them and then get() them, which may raise an exception if any of them
# died with an exception.
self.thread_manager.wait_children(30)
PyonThread._notify_stop(self)
# run the cleanup method if we have one
if self._cleanup_method is not None:
try:
self._cleanup_method(self)
except Exception as ex:
log.warn(
"Cleanup method error, attempting to ignore: %s\nTraceback: %s",
ex, traceback.format_exc())
def get_ready_event(self):
"""
Returns an Event that is set when the control greenlet is up and running.
"""
return self._ready_control
class IonProcessThread(PyonThread):
"""
Form the base of an ION process.
"""
def __init__(self, target=None, listeners=None, name=None, service=None, cleanup_method=None, **kwargs):
"""
Constructs an ION process.
You don't create one of these directly, the IonProcessThreadManager run by a container does this for
you via the ProcManager interface. Call the container's spawn_process method and this method will run.
@param target A callable to run in the PyonThread. If None (typical), will use the target method
defined in this class.
@param listeners A list of listening endpoints attached to this thread.
@param name The name of this ION process.
@param service An instance of the BaseService derived class which contains the business logic for
an ION process.
@param cleanup_method An optional callable to run when the process is stopping. Runs after all other
notify_stop calls have run. Should take one param, this instance.
"""
self._startup_listeners = listeners or []
self.listeners = []
self.name = name
self.service = service
self._cleanup_method = cleanup_method
self.thread_manager = ThreadManager(failure_notify_callback=self._child_failed) # bubbles up to main thread manager
self._ctrl_queue = Queue()
self._ready_control = Event()
PyonThread.__init__(self, target=target, **kwargs)
def _child_failed(self, child):
"""
Occurs when any child greenlet fails.
Propogates the error up to the process supervisor.
"""
self.proc.kill(child.exception)
def add_endpoint(self, listener):
"""
Adds a listening endpoint to this ION process.
Spawns the listen loop and sets the routing call to synchronize incoming messages
here. If this process hasn't been started yet, adds it to the list of listeners
to start on startup.
"""
if self.proc:
listener.routing_call = self._routing_call
self.thread_manager.spawn(listener.listen)
self.listeners.append(listener)
else:
self._startup_listeners.append(listener)
def target(self, *args, **kwargs):
"""
Control entrypoint. Setup the base properties for this process (mainly a listener).
"""
if self.name:
threading.current_thread().name = self.name
# spawn control flow loop
ct = self.thread_manager.spawn(self._control_flow)
# wait on control flow loop!
ct.get()
def _routing_call(self, call, context, *callargs, **callkwargs):
"""
Endpoints call into here to synchronize across the entire IonProcess.
Returns immediately with an AsyncResult that can be waited on. Calls
are made by the loop in _control_flow. We pass in the calling greenlet so
exceptions are raised in the correct context.
@param call The call to be made within this ION processes' calling greenlet.
@param callargs The keyword args to pass to the call.
@param context Optional process-context (usually the headers of the incoming call) to be
set. Process-context is greenlet-local, and since we're crossing greenlet
boundaries, we must set it again in the ION process' calling greenlet.
"""
ar = AsyncResult()
if len(callargs) == 0 and len(callkwargs) == 0:
log.warn("_routing_call got no arguments for the call %s, check your call's parameters", call)
self._ctrl_queue.put((greenlet.getcurrent(), ar, call, callargs, callkwargs, context))
return ar
def _control_flow(self):
"""
Main process thread of execution method.
This method is run inside a greenlet and exists for each ION process. Listeners
attached to the process, either RPC Servers or Subscribers, synchronize their calls
by placing future calls into the queue by calling _routing_call. This is all done
automatically for you by the Container's Process Manager.
This method blocks until there are calls to be made in the synchronized queue, and
then calls from within this greenlet. Any exception raised is caught and re-raised
in the greenlet that originally scheduled the call. If successful, the AsyncResult
created at scheduling time is set with the result of the call.
"""
self._ready_control.set()
for calltuple in self._ctrl_queue:
calling_gl, ar, call, callargs, callkwargs, context = calltuple
log.debug("control_flow making call: %s %s %s (has context: %s)", call, callargs, callkwargs, context is not None)
res = None
try:
with self.service.push_context(context):
res = call(*callargs, **callkwargs)
except Exception as e:
# raise the exception in the calling greenlet, and don't
# wait for it to die - it's likely not going to do so.
# try decorating the args of the exception with the true traceback
# this should be reported by ThreadManager._child_failed
exc = PyonThreadTraceback("IonProcessThread _control_flow caught an exception (call: %s, *args %s, **kwargs %s, context %s)\nTrue traceback captured by IonProcessThread' _control_flow:\n\n%s" % (call, callargs, callkwargs, context, traceback.format_exc()))
e.args = e.args + (exc,)
calling_gl.kill(exception=e, block=False)
ar.set(res)
def start_listeners(self):
"""
Starts all listeners in managed greenlets.
This must be called after starting this IonProcess. Currently, the Container's ProcManager
will handle this for you, but if using an IonProcess manually, you must remember to call
this method or no attached listeners will run.
"""
# spawn all listeners in startup listeners (from initializer, or added later)
for listener in self._startup_listeners:
self.add_endpoint(listener)
ev = Event()
def allready(ev):
waitall([x.get_ready_event() for x in self.listeners])
ev.set()
spawn(allready, ev)
ev.wait(timeout=10)
def _notify_stop(self):
"""
Called when the process is about to be shut down.
Instructs all listeners to close, puts a StopIteration into the synchronized queue,
and waits for the listeners to close and for the control queue to exit.
"""
map(lambda x: x.close(), self.listeners)
self._ctrl_queue.put(StopIteration)
# wait_children will join them and then get() them, which may raise an exception if any of them
# died with an exception.
self.thread_manager.wait_children(30)
PyonThread._notify_stop(self)
# run the cleanup method if we have one
if self._cleanup_method is not None:
self._cleanup_method(self)
def get_ready_event(self):
"""
Returns an Event that is set when the control greenlet is up and running.
"""
return self._ready_control
