Pika Driver Deployment Guide

Warning

the Pika driver is no longer maintained and will be removed from Oslo.Messaging at a future date. It is recommended that all users of the Pika driver transition to using the Rabbit driver.

Introduction

Pika is a pure-Python implementation of the AMQP 0-9-1 protocol including RabbitMQ’s extensions. It is very actively supported and recommended by RabbitMQ developers

Abstract

PikaDriver is one of oslo.messaging backend drivers. It supports RPC and Notify patterns. Currently it could be the only oslo.messaging driver across the OpenStack cluster. This document provides deployment information for this driver in oslo_messaging.

This driver is able to work with single instance of RabbitMQ server or RabbitMQ cluster.

Configuration

Enabling (mandatory)

To enable the driver, in the section [DEFAULT] of the conf file, the ‘transport_url’ parameter should be set to pika://user:pass@host1:port[,hostN:portN]

[DEFAULT] transport_url = pika://guest:guest@localhost:5672

Connection options (optional)

In section [oslo_messaging_pika]: #. channel_max - Maximum number of channels to allow,

1. frame_max (default - pika default value): The maximum byte size for an AMQP frame,
2. heartbeat_interval (default=1): How often to send heartbeats for consumer’s connections in seconds. If 0 - disable heartbeats,
3. ssl (default=False): Enable SSL if True,
4. ssl_options (default=None): Arguments passed to ssl.wrap_socket,
5. socket_timeout (default=0.25): Set timeout for opening new connection’s socket,
6. tcp_user_timeout (default=0.25): Set TCP_USER_TIMEOUT in seconds for connection’s socket,
7. host_connection_reconnect_delay (default=0.25): Set delay for reconnection to some host after connection error

Connection pool options (optional)

In section [oslo_messaging_pika]:

1. pool_max_size (default=10): Maximum number of connections to keep queued,
2. pool_max_overflow (default=0): Maximum number of connections to create above pool_max_size,
3. pool_timeout (default=30): Default number of seconds to wait for a connections to available,
4. pool_recycle (default=600): Lifetime of a connection (since creation) in seconds or None for no recycling. Expired connections are closed on acquire,
5. pool_stale (default=60): Threshold at which inactive (since release) connections are considered stale in seconds or None for no staleness. Stale connections are closed on acquire.”)

RPC related options (optional)

In section [oslo_messaging_pika]:

1. rpc_queue_expiration (default=60): Time to live for rpc queues without consumers in seconds,
2. default_rpc_exchange (default=”${control_exchange}_rpc”): Exchange name for sending RPC messages,
3. rpc_reply_exchange’, default=(“${control_exchange}_rpc_reply”): Exchange name for receiving RPC replies,
4. rpc_listener_prefetch_count (default=100): Max number of not acknowledged message which RabbitMQ can send to rpc listener,
5. rpc_reply_listener_prefetch_count (default=100): Max number of not acknowledged message which RabbitMQ can send to rpc reply listener,
6. rpc_reply_retry_attempts (default=-1): Reconnecting retry count in case of connectivity problem during sending reply. -1 means infinite retry during rpc_timeout,
7. rpc_reply_retry_delay (default=0.25) Reconnecting retry delay in case of connectivity problem during sending reply,
8. default_rpc_retry_attempts (default=-1): Reconnecting retry count in case of connectivity problem during sending RPC message, -1 means infinite retry. If actual retry attempts in not 0 the rpc request could be processed more than one time,
9. rpc_retry_delay (default=0.25): Reconnecting retry delay in case of connectivity problem during sending RPC message

$control_exchange in this code is value of [DEFAULT].control_exchange option, which is “openstack” by default

Notification related options (optional)

In section [oslo_messaging_pika]:

1. notification_persistence (default=False): Persist notification messages,
2. default_notification_exchange (default=”${control_exchange}_notification”): Exchange name for sending notifications,
3. notification_listener_prefetch_count (default=100): Max number of not acknowledged message which RabbitMQ can send to notification listener,

4. default_notification_retry_attempts (default=-1): Reconnecting retry count

   in case of connectivity problem during sending notification, -1 means infinite retry,

5. notification_retry_delay (default=0.25): Reconnecting retry delay in case of connectivity problem during sending notification message

$control_exchange in this code is value of [DEFAULT].control_exchange option, which is “openstack” by default

DevStack Support

Pika driver is supported by DevStack. To enable it you should edit local.conf [localrc] section and add next there:

enable_plugin pika https://git.openstack.org/openstack/devstack-plugin-pika