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oslo.messaging
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[zmq] Update zmq-guide with new options 

In this change updated:

* Redis TTL 'zmq_target_expire'
* Proxy for RPC 'direct_over_proxy'
* PUB/SUB usage 'use_pub_sub'

Change-Id: Id3cf1a88353b8c876a307d759c81934df9d62c6a
This commit is contained in:
Oleksii Zamiatin 2016-01-15 14:32:00 +02:00
parent 62fc6ab094
commit 0b350f2bf6
1 changed files with 19 additions and 14 deletions
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33
doc/source/zmq_driver.rst
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@ -32,17 +32,8 @@ More detail regarding ZeroMQ library is available from the `specification`_.
Abstract Abstract
======== ========
In Folsom, OpenStack introduced an optional messaging system using ZeroMQ. Currently, ZeroMQ is one of the RPC backend drivers in oslo.messaging. ZeroMQ
For some deployments, especially for those super-large scenarios, it may be can be the only RPC driver across the OpenStack cluster.
desirable to use a broker-less RPC mechanism to scale out.
The original deployment guide only supports Nova in `folsom`_.
.. _folsom: http://ewindisch.github.io/nova
Currently, ZeroMQ is one of the RPC backend drivers in oslo.messaging. In the
Juno release, as almost all the core projects in OpenStack have switched to
oslo_messaging, ZeroMQ can be the only RPC driver across the OpenStack cluster.
This document provides deployment information for this driver in oslo_messaging. This document provides deployment information for this driver in oslo_messaging.
Other than AMQP-based drivers, like RabbitMQ, ZeroMQ doesn't have Other than AMQP-based drivers, like RabbitMQ, ZeroMQ doesn't have
@ -129,6 +120,11 @@ To specify the Redis server for RedisMatchMaker, use options in
port = 6379 port = 6379
password = None password = None
In order to cleanup redis storage from expired records (e.g. target listener
goes down) TTL may be applied for keys. Configure 'zmq_target_expire' option
which is 120 (seconds) by default. The option is related not specifically to
redis so it is also defined in [DEFAULT] section. If option value is <= 0
then keys don't expire and live forever in the storage.
MatchMaker Data Source (mandatory) MatchMaker Data Source (mandatory)
---------------------------------- ----------------------------------
@ -149,12 +145,21 @@ Each machine running OpenStack services, or sending RPC messages, may run the
'oslo-messaging-zmq-broker' daemon. This is needed to avoid blocking 'oslo-messaging-zmq-broker' daemon. This is needed to avoid blocking
if a listener (server) appears after the sender (client). if a listener (server) appears after the sender (client).
Running the local broker (proxy) or not is defined by the option 'zmq_use_broker' Fanout-based patterns like CAST+Fanout and notifications always use proxy
(True by default). This option can be set in [DEFAULT] section. as they act over PUB/SUB, 'use_pub_sub' - defaults to True. If not using
PUB/SUB (use_pub_sub = False) then fanout will be emulated over direct
DEALER/ROUTER unicast which is possible but less efficient and therefore
is not recommended.
Running direct RPC methods like CALL and CAST over a proxy is controlled by
the option 'direct_over_proxy' which is True by default.
These options can be set in [DEFAULT] section.
For example:: For example::
zmq_use_broker = False use_pub_sub = True
direct_over_proxy = False
In case of using the broker all publishers (clients) talk to servers over In case of using the broker all publishers (clients) talk to servers over