def _wait_child(self): try: # Don't block if no child processes have exited pid, status = os.waitpid(0, os.WNOHANG) if not pid: return None except OSError as exc: if exc.errno not in (errno.EINTR, errno.ECHILD): raise return None if os.WIFSIGNALED(status): sig = os.WTERMSIG(status) LOG.info(_LI("Child %(pid)d killed by signal %(sig)d"), dict(pid=pid, sig=sig)) else: code = os.WEXITSTATUS(status) LOG.info(_LI("Child %(pid)s exited with status %(code)d"), dict(pid=pid, code=code)) if pid not in self.children: LOG.warning(_LW("pid %d not in child list"), pid) return None wrap = self.children.pop(pid) wrap.children.remove(pid) return wrap
def wait(self): """Loop waiting on children to die and respawning as necessary.""" systemd.notify_once() LOG.debug("Full set of CONF:") CONF.log_opt_values(LOG, std_logging.DEBUG) try: while True: self.handle_signal() self._respawn_children() # No signal means that stop was called. Don't clean up here. if not self.sigcaught: return signame = _signo_to_signame(self.sigcaught) LOG.info(_LI("Caught %s, stopping children"), signame) if not _is_sighup_and_daemon(self.sigcaught): break for pid in self.children: os.kill(pid, signal.SIGHUP) self.running = True self.sigcaught = None except eventlet.greenlet.GreenletExit: LOG.info(_LI("Wait called after thread killed. Cleaning up.")) self.stop()
def _start_child(self, wrap): if len(wrap.forktimes) > wrap.workers: # Limit ourselves to one process a second (over the period of # number of workers * 1 second). This will allow workers to # start up quickly but ensure we don't fork off children that # die instantly too quickly. if time.time() - wrap.forktimes[0] < wrap.workers: LOG.info(_LI("Forking too fast, sleeping")) time.sleep(1) wrap.forktimes.pop(0) wrap.forktimes.append(time.time()) pid = os.fork() if pid == 0: launcher = self._child_process(wrap.service) while True: self._child_process_handle_signal() status, signo = self._child_wait_for_exit_or_signal(launcher) if not _is_sighup_and_daemon(signo): break launcher.restart() os._exit(status) LOG.info(_LI("Started child %d"), pid) wrap.children.add(pid) self.children[pid] = wrap return pid
def _wait_for_exit_or_signal(self, ready_callback=None): status = None signo = 0 LOG.debug("Full set of CONF:") CONF.log_opt_values(LOG, std_logging.DEBUG) try: if ready_callback: ready_callback() super(ServiceLauncher, self).wait() except SignalExit as exc: signame = _signo_to_signame(exc.signo) LOG.info(_LI("Caught %s, exiting"), signame) status = exc.code signo = exc.signo except SystemExit as exc: status = exc.code finally: self.stop() if rpc: try: rpc.cleanup() except Exception: # We're shutting down, so it doesn't matter at this point. LOG.exception(_LE("Exception during rpc cleanup.")) return status, signo
def _pipe_watcher(self): # This will block until the write end is closed when the parent # dies unexpectedly self.readpipe.read() LOG.info(_LI("Parent process has died unexpectedly, exiting")) sys.exit(1)
def __init__(cls, names, bases, dict_): """Metaclass that allows us to collect decorated periodic tasks.""" super(_PeriodicTasksMeta, cls).__init__(names, bases, dict_) # NOTE(sirp): if the attribute is not present then we must be the base # class, so, go ahead an initialize it. If the attribute is present, # then we're a subclass so make a copy of it so we don't step on our # parent's toes. try: cls._periodic_tasks = cls._periodic_tasks[:] except AttributeError: cls._periodic_tasks = [] try: cls._periodic_spacing = cls._periodic_spacing.copy() except AttributeError: cls._periodic_spacing = {} for value in cls.__dict__.values(): if getattr(value, '_periodic_task', False): task = value name = task.__name__ if task._periodic_spacing < 0: LOG.info(_LI('Skipping periodic task %(task)s because ' 'its interval is negative'), {'task': name}) continue if not task._periodic_enabled: LOG.info(_LI('Skipping periodic task %(task)s because ' 'it is disabled'), {'task': name}) continue # A periodic spacing of zero indicates that this task should # be run on the default interval to avoid running too # frequently. if task._periodic_spacing == 0: task._periodic_spacing = DEFAULT_INTERVAL cls._periodic_tasks.append((name, task)) cls._periodic_spacing[name] = task._periodic_spacing
def drop_old_duplicate_entries_from_table(migrate_engine, table_name, use_soft_delete, *uc_column_names): """Drop all old rows having the same values for columns in uc_columns. This method drop (or mark ad `deleted` if use_soft_delete is True) old duplicate rows form table with name `table_name`. :param migrate_engine: Sqlalchemy engine :param table_name: Table with duplicates :param use_soft_delete: If True - values will be marked as `deleted`, if False - values will be removed from table :param uc_column_names: Unique constraint columns """ meta = MetaData() meta.bind = migrate_engine table = Table(table_name, meta, autoload=True) columns_for_group_by = [table.c[name] for name in uc_column_names] columns_for_select = [func.max(table.c.id)] columns_for_select.extend(columns_for_group_by) duplicated_rows_select = sqlalchemy.sql.select( columns_for_select, group_by=columns_for_group_by, having=func.count(table.c.id) > 1) for row in migrate_engine.execute(duplicated_rows_select): # NOTE(boris-42): Do not remove row that has the biggest ID. delete_condition = table.c.id != row[0] is_none = None # workaround for pyflakes delete_condition &= table.c.deleted_at == is_none for name in uc_column_names: delete_condition &= table.c[name] == row[name] rows_to_delete_select = sqlalchemy.sql.select( [table.c.id]).where(delete_condition) for row in migrate_engine.execute(rows_to_delete_select).fetchall(): LOG.info(_LI("Deleting duplicated row with id: %(id)s from table: " "%(table)s") % dict(id=row[0], table=table_name)) if use_soft_delete: delete_statement = table.update().\ where(delete_condition).\ values({ 'deleted': literal_column('id'), 'updated_at': literal_column('updated_at'), 'deleted_at': timeutils.utcnow() }) else: delete_statement = table.delete().where(delete_condition) migrate_engine.execute(delete_statement)
def stop(self): """Terminate child processes and wait on each.""" self.running = False for pid in self.children: try: os.kill(pid, signal.SIGTERM) except OSError as exc: if exc.errno != errno.ESRCH: raise # Wait for children to die if self.children: LOG.info(_LI("Waiting on %d children to exit"), len(self.children)) while self.children: self._wait_child()
def _child_wait_for_exit_or_signal(self, launcher): status = 0 signo = 0 # NOTE(johannes): All exceptions are caught to ensure this # doesn't fallback into the loop spawning children. It would # be bad for a child to spawn more children. try: launcher.wait() except SignalExit as exc: signame = _signo_to_signame(exc.signo) LOG.info(_LI("Child caught %s, exiting"), signame) status = exc.code signo = exc.signo except SystemExit as exc: status = exc.code except BaseException: LOG.exception(_LE("Unhandled exception")) status = 2 finally: launcher.stop() return status, signo
def _child_wait_for_exit_or_signal(self, launcher): status = 0 signo = 0 # NOTE(johannes): All exceptions are caught to ensure this # doesn't fallback into the loop spawning children. It would # be bad for a child to spawn more children. try: launcher.wait() except SignalExit as exc: signame = _signo_to_signame(exc.signo) LOG.info(_LI('Child caught %s, exiting'), signame) status = exc.code signo = exc.signo except SystemExit as exc: status = exc.code except BaseException: LOG.exception(_LE('Unhandled exception')) status = 2 finally: launcher.stop() return status, signo
def launch_service(self, service, workers=1): wrap = ServiceWrapper(service, workers) LOG.info(_LI("Starting %d workers"), wrap.workers) while self.running and len(wrap.children) < wrap.workers: self._start_child(wrap)
def launch_service(self, service, workers=1): wrap = ServiceWrapper(service, workers) LOG.info(_LI('Starting %d workers'), wrap.workers) while self.running and len(wrap.children) < wrap.workers: self._start_child(wrap)