Add two flags:
* enable_rpc_ha which enables queue mirroring for RPC queues
* enable_notifications_ha which enables queue mirroring for
Ceilometer queues
Since the feature is experimental, both flags are set to true by
default to preserve current behaviour.
The change is implemented in several steps:
* the upstream script changed so that it allows to extend the
list of parameters and uses a policy file to define RabbitMQ
policies.
* we add our own version of OCF script which wraps around the
upstream one. It defines a new enable_rpc_ha and
enable_notifications_ha parameter and passes their value to the
upstream script.
* we add our policy file, where we use the introduced parameters
to decide which policies we should set.
So we will have two OCF scripts for RabbitMQ in our deployment:
* rabbitmq-server-upstream - the upstream version
* rabbitmq-server - our extention, which will be used in the
environment
The upstream version of the script is pushed to the upstream
along with empty policy file, so that other users can define their
own policies or extend the script if needed. Here are the
corresponding pull requests:
https://github.com/rabbitmq/rabbitmq-server/pull/480https://github.com/rabbitmq/rabbitmq-server/pull/482
(both are already merged)
Text for Operations Guide
It is possible to significantly reduce load which OpenStack puts on
RabbitMQ by disabling queue mirroring. This could be done separately
for RPC queues and Ceilometer ones. To disable mirroring for RPC
queues, execute the following command on one of the controllers:
crm_resource --resource p_rabbitmq-server --set-parameter \
enable_rpc_ha --parameter-value false
To disable mirroring for Ceilometer queues, execute the following
command on one of the controllers:
crm_resource --resource p_rabbitmq-server --set-parameter \
enable_notifications_ha --parameter-value false
In order for any of the changes to take effect, RabbitMQ service
should be restarted. To do that, first execute
pcs resource disable master_p_rabbitmq-server
Then monitor RabbitMQ state using command
pcs resource
until it shows that all RabbitMQ nodes are stopped. Once they are,
execute the following command to start RabbitMQ:
pcs resource enable master_p_rabbitmq-server
Beware: during restart all messages accumulated in RabbitMQ will be
lost. Also, OpenStack will stop functioning until RabbitMQ is up
again, so plan accordingly.
Note that it is not yet well tested how this configuration affects
failover when some cluster nodes go down. Hence it is experimental,
use at your own risk!
DocImpact: ops-guide
Implements: blueprint rabbitmq-disable-mirroring-for-rpc
Change-Id: I80ae231ca64e2a903b0968d36ba0e85ca9cc9891
7e96ef47ca