#!/usr/bin/env python3 import logging import threading import time from typing import Optional import zmq from parsl import curvezmq from parsl.addresses import tcp_url from parsl.errors import InternalConsistencyError from parsl.executors.high_throughput.errors import ( CommandClientBadError, CommandClientTimeoutError, ) logger = logging.getLogger(__name__) class CommandClient: """ CommandClient """ def __init__(self, ip_address, port_range, cert_dir: Optional[str] = None): """ Parameters ---------- ip_address: str IP address of the client (where Parsl runs) port_range: tuple(int, int) Port range for the comms between client and interchange cert_dir: str | None Path to the certificate directory. Setting this to None will disable encryption. default: None """ self.zmq_context = curvezmq.ClientContext(cert_dir) self.ip_address = ip_address self.port_range = port_range self.port = None self.create_socket_and_bind() self._lock = threading.Lock() self.ok = True def create_socket_and_bind(self): """ Creates socket and binds to a port. Upon recreating the socket, we bind to the same port. """ self.zmq_socket = self.zmq_context.socket(zmq.REQ) self.zmq_socket.setsockopt(zmq.LINGER, 0) if self.port is None: self.port = self.zmq_socket.bind_to_random_port(tcp_url(self.ip_address), min_port=self.port_range[0], max_port=self.port_range[1]) else: self.zmq_socket.bind(tcp_url(self.ip_address, self.port)) def run(self, message, max_retries=3, timeout_s=None): """ This function needs to be fast at the same time aware of the possibility of ZMQ pipes overflowing. We could set copy=False and get slightly better latency but this results in ZMQ sockets reaching a broken state once there are ~10k tasks in flight. This issue can be magnified if each the serialized buffer itself is larger. """ if not self.ok: raise CommandClientBadError() start_time_s = time.monotonic() reply = '__PARSL_ZMQ_PIPES_MAGIC__' with self._lock: for _ in range(max_retries): try: logger.debug("Sending command client command") if timeout_s is not None: remaining_time_s = start_time_s + timeout_s - time.monotonic() poll_result = self.zmq_socket.poll(timeout=remaining_time_s * 1000, flags=zmq.POLLOUT) if poll_result == zmq.POLLOUT: pass # this is OK, so continue elif poll_result == 0: raise CommandClientTimeoutError("Waiting for command channel to be ready for a command") else: raise InternalConsistencyError(f"ZMQ poll returned unexpected value: {poll_result}") self.zmq_socket.send_pyobj(message, copy=True) if timeout_s is not None: logger.debug("Polling for command client response or timeout") remaining_time_s = start_time_s + timeout_s - time.monotonic() poll_result = self.zmq_socket.poll(timeout=remaining_time_s * 1000, flags=zmq.POLLIN) if poll_result == zmq.POLLIN: pass # this is OK, so continue elif poll_result == 0: logger.error("Command timed-out - command client is now bad forever") self.ok = False raise CommandClientTimeoutError("Waiting for a reply from command channel") else: raise InternalConsistencyError(f"ZMQ poll returned unexpected value: {poll_result}") logger.debug("Receiving command client response") reply = self.zmq_socket.recv_pyobj() logger.debug("Received command client response") except zmq.ZMQError: logger.exception("Potential ZMQ REQ-REP deadlock caught") logger.info("Trying to reestablish context") self.zmq_context.recreate() self.create_socket_and_bind() else: break if reply == '__PARSL_ZMQ_PIPES_MAGIC__': logger.error("Command channel run retries exhausted. Unable to run command") raise Exception("Command Channel retries exhausted") return reply def close(self): self.zmq_socket.close() self.zmq_context.term() class TasksOutgoing: """ Outgoing task queue from the executor to the Interchange """ def __init__(self, ip_address, port_range, cert_dir: Optional[str] = None): """ Parameters ---------- ip_address: str IP address of the client (where Parsl runs) port_range: tuple(int, int) Port range for the comms between client and interchange cert_dir: str | None Path to the certificate directory. Setting this to None will disable encryption. default: None """ self.zmq_context = curvezmq.ClientContext(cert_dir) self.zmq_socket = self.zmq_context.socket(zmq.DEALER) self.zmq_socket.set_hwm(0) self.port = self.zmq_socket.bind_to_random_port(tcp_url(ip_address), min_port=port_range[0], max_port=port_range[1]) self.poller = zmq.Poller() self.poller.register(self.zmq_socket, zmq.POLLOUT) def put(self, message): """ This function needs to be fast at the same time aware of the possibility of ZMQ pipes overflowing. The timeout increases slowly if contention is detected on ZMQ pipes. We could set copy=False and get slightly better latency but this results in ZMQ sockets reaching a broken state once there are ~10k tasks in flight. This issue can be magnified if each the serialized buffer itself is larger. """ timeout_ms = 1 while True: socks = dict(self.poller.poll(timeout=timeout_ms)) if self.zmq_socket in socks and socks[self.zmq_socket] == zmq.POLLOUT: # The copy option adds latency but reduces the risk of ZMQ overflow logger.debug("Sending TasksOutgoing message") self.zmq_socket.send_pyobj(message, copy=True) logger.debug("Sent TasksOutgoing message") return else: timeout_ms *= 2 logger.debug("Not sending due to non-ready zmq pipe, timeout: {} ms".format(timeout_ms)) def close(self): self.zmq_socket.close() self.zmq_context.term() class ResultsIncoming: """ Incoming results queue from the Interchange to the executor """ def __init__(self, ip_address, port_range, cert_dir: Optional[str] = None): """ Parameters ---------- ip_address: str IP address of the client (where Parsl runs) port_range: tuple(int, int) Port range for the comms between client and interchange cert_dir: str | None Path to the certificate directory. Setting this to None will disable encryption. default: None """ self.zmq_context = curvezmq.ClientContext(cert_dir) self.results_receiver = self.zmq_context.socket(zmq.DEALER) self.results_receiver.set_hwm(0) self.port = self.results_receiver.bind_to_random_port(tcp_url(ip_address), min_port=port_range[0], max_port=port_range[1]) self.poller = zmq.Poller() self.poller.register(self.results_receiver, zmq.POLLIN) def get(self, timeout_ms=None): """Get a message from the queue, returning None if timeout expires without a message. timeout is measured in milliseconds. """ logger.debug("Waiting for ResultsIncoming message") socks = dict(self.poller.poll(timeout=timeout_ms)) if self.results_receiver in socks and socks[self.results_receiver] == zmq.POLLIN: m = self.results_receiver.recv_multipart() logger.debug("Received ResultsIncoming message") return m else: return None def close(self): self.results_receiver.close() self.zmq_context.term()