def _stop_server(node, expr):
"""Instruct single server to stop.
Send stop command and then terminate process. Add port back to those available to new servers.
"""
root, path = lib.expr_split(expr)
try:
RemoteProcedureCall._send_to_server(node, root, 'stop')
time.sleep(0.1)
server_dict[expr]["process"].terminate()
port_number_lock.acquire()
allocated_port_number.append(server_dict[expr]["port"])
port_number_lock.release()
node.print_info(TAG, "Server stopped with expr: %s" % expr)
except Exception as e:
node.print_error(
TAG,
"Error occured with 'stop' command for expression '%s': %s" %
(expr, e))
raise lib.RemoteProcedureCallError(data={
'exception': str(e),
'node_id': str(node.node_id),
'expr': str(expr)
},
code='-32603')
def _start_new_server(node, expr):
"""Create a single (new) server.
Use next available port to start server process. Store server process and port.
"""
root, path = lib.expr_split(expr)
try:
try:
port_number_lock.acquire()
port = allocated_port_number.popleft()
port_number_lock.release()
except IndexError:
node.print_error(
TAG,
"No ports remaining in allocation, cannot start new server."
)
return False
process = multiprocessing.Process(target=server.Server,
args=(node, root, port))
process.daemon = True
process.start()
server_dict[expr] = {"process": process, "port": port}
node.print_info(TAG, "New server started with expr: %s" % expr)
except Exception as e:
node.print_error(
TAG,
"Error occured with 'start' (new server) for expression '%s': %s"
% (expr, e))
raise lib.RemoteProcedureCallError(data={
'exception': str(e),
'node_id': str(node.node_id),
'expr': str(expr)
},
code='-32603')
def _call_method(self, rpc):
try:
result = getattr(self.controller, rpc.method)(rpc)
return result
except AttributeError:
raise lib.RemoteProcedureCallError(
data=('Controller has no method named: %s' % rpc.method),
code='-32601')
def stat(self, rpc):
"""Retrieve statistics from the database.
Handle the three permutations of node descriptions (all, list or single). Do final calculations and conversion
for the aggregate statistic.
"""
try:
total_result = dict([('total_cache_miss', 0),
('total_cache_miss_size', 0),
('total_cache_hit', 0),
('total_cache_hit_size', 0),
('total_cache_object', 0),
('total_cache_object_size', 0), ('start', 0),
('stop', 0), ('pause', 0),
('total_response_count', 0),
('total_node_id_count', 0),
('total_expr_count', 0),
('node_id_seen', set()), ('expr_seen', set()),
('node_expr_pairs_seen', set())])
if rpc.node_id == '*':
for node in self._state.list_nodes():
total_result = self._stat_node(rpc.expr, node,
total_result)
elif "|" in rpc.node_id:
for node in rpc.node_id.split("|"):
total_result = self._stat_node(rpc.expr, node,
total_result)
else:
total_result = self._stat_node(rpc.expr, rpc.node_id,
total_result)
total_result['total_node_id_count'] = len(
total_result['node_id_seen'])
total_result['total_expr_count'] = len(total_result['expr_seen'])
total_result['total_response_count'] = len(
total_result['node_expr_pairs_seen'])
total_result['node_id_seen'] = list(total_result['node_id_seen'])
total_result['expr_seen'] = list(total_result['expr_seen'])
total_result['node_expr_pairs_seen'] = list(
total_result['node_expr_pairs_seen'])
return total_result
except Exception as e:
raise lib.RemoteProcedureCallError(data={
'exception': str(e),
'node_id': str(node.node_id),
'expr': str(rpc.expr)
},
code='-32603')
def _validate_request(self, rpc):
try:
if "id" not in rpc.request:
raise Exception
else:
rpc.id = str(rpc.request["id"])
if "method" not in rpc.request or "params" not in rpc.request or "jsonrpc" not in rpc.request:
raise Exception
else:
rpc.method = str(rpc.request["method"])
rpc.params = rpc.request["params"]
return rpc
except Exception:
raise lib.RemoteProcedureCallError(
data='The JSON sent is not a valid Request object.',
code='-32600')
def _stat_server(node, expr):
"""Instruct single server to return statistics to controller."""
root, path = lib.expr_split(expr)
try:
RemoteProcedureCall._send_to_server(node, root, 'stat')
node.print_info(TAG, "Server stat'ed with expr: %s" % expr)
except Exception as e:
node.print_error(
TAG,
"Error occured with 'stat' command for expression '%s': %s" %
(expr, e))
raise lib.RemoteProcedureCallError(data={
'exception': str(e),
'node_id': str(node.node_id),
'expr': str(expr)
},
code='-32603')
def _seed_server(node, expr, transaction):
root, path = lib.expr_split(expr)
object_dict[expr] = transaction
try:
key = hashlib.sha224(path).hexdigest()
path = node.config["cache_path"] + 'shared/' + transaction
node.database.create({'key': key, 'path': path})
node.print_info(TAG, "Server seeded with expression: %s" % expr)
except Exception as e:
node.print_error(
TAG,
"Error occured with 'seed' command for expression '%s': %s" %
(expr, e))
raise lib.RemoteProcedureCallError(data={
'exception': str(e),
'node_id': str(node.node_id),
'expr': str(expr)
},
code='-32603')
def _validate_method_params(self, rpc):
try:
if rpc.method == 'hello':
if "host" in rpc.params and "port" in rpc.params:
rpc.host = str(rpc.params["host"])
rpc.port = str(rpc.params["port"])
else:
raise Exception
elif rpc.method == "keep_alive" or rpc.method == "goodbye":
if "node-id" in rpc.params:
rpc.node_id = str(rpc.params["node-id"])
else:
raise Exception
else:
if "node-id" in rpc.params:
rpc.node_id = str(rpc.params["node-id"])
if "expr" in rpc.params:
rpc.expr = str(rpc.params["expr"])
return rpc
except Exception:
raise lib.RemoteProcedureCallError(
data='Invalid method parameter(s).', code='-32602')
def fetch(self, rpc):
"""Send fetch requests to given nodes.
Handle the three permutations of node descriptions (all, list or single).
"""
try:
if rpc.node_id == '*':
for node in self._state.list_nodes():
self._fetch_node(rpc.expr, node)
elif "|" in rpc.node_id:
for node in rpc.node_id.split("|"):
self._fetch_node(rpc.expr, node)
else:
self._fetch_node(rpc.expr, rpc.node_id)
return True
except Exception as e:
raise lib.RemoteProcedureCallError(data={
'exception': str(e),
'node_id': str(node.node_id),
'expr': str(rpc.expr)
},
code='-32603')