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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
========
In Folsom, OpenStack introduced an optional messaging system using ZeroMQ.
For some deployments, especially for those super-large scenarios, it may be
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.
Currently, ZeroMQ is one of the RPC backend drivers in oslo.messaging. ZeroMQ
can be the only RPC driver across the OpenStack cluster.
This document provides deployment information for this driver in oslo_messaging.
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
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)
----------------------------------
@ -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
if a listener (server) appears after the sender (client).
Running the local broker (proxy) or not is defined by the option 'zmq_use_broker'
(True by default). This option can be set in [DEFAULT] section.
Fanout-based patterns like CAST+Fanout and notifications always use proxy
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::
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