Swift Proxy Server Workers Defaults to a single process

[Alex Krzos]

OpenStack Swift Proxy Server Daemon (swift-proxy-server) should be configured with more than one process/worker for performance and scalability. This was found on Newton bits.

The configured default is a single worker despite the puppet-swift installer (For Newton) showing it should configure more than a single worker (processor count) [0] We should at a minimum, configure more than a single daemon per the Swift General Service Tuning document [1]

You can work around this by passing an additional yaml template into the openstack deploy command to expand the number of workers:

parameter_defaults:
  SwiftWorkers: 24

The actual General Service Tuning recommends 2 x physical cpu core count though it mentions further experiments might be necessary if the server shares other services running on it. (Such as our controllers)

Reviewing the configuration for the swift-proxy-server shows it is configured for a single worker by default by being tuned to:
workers = 0

Thus it suggests something is overriding the configuration by the puppet-swift installer.

In actually testing for scalability of Gnocchi processing metrics on instances with a swift storage backend, it has shown that a single swift-proxy worker will peg a single cpu core at 100 instances ( Technically three workers each pegging a cpu core across 3 controllers - ha deployment)

[0] https://github.com/openstack/puppet-swift/blob/stable/newton/manifests/proxy.pp#L28
[1] http://docs.openstack.org/developer/swift/deployment_guide.html#general-service-tuning

[OpenStack Infra (hudson-openstack)]

Fix proposed to branch: master
Review: https://review.openstack.org/418029

[OpenStack Infra (hudson-openstack)]

Reviewed: https://review.openstack.org/418029
Committed: https://git.openstack.org/cgit/openstack/tripleo-heat-templates/commit/?id=892827c639d7b72ff2020e5f3fa5bc6db6a608df
Submitter: Jenkins
Branch: master

commit 892827c639d7b72ff2020e5f3fa5bc6db6a608df
Author: Christian Schwede <email address hidden>
Date: Mon Jan 9 19:04:39 2017 +0000

    Set number of Swift proxy server workers to auto

    Setting the default Swift proxy workers to 0 actually results in a
    single Swift proxy worker, no matter how many CPU cores are available.
    This is not the default Swift setting and is most likely not sufficient.

    Setting this to auto uses the default in Swift, which equals to the
    number of CPU cores.

    Closes-Bug: 1655070
    Change-Id: Ic321b6111f8697ba3cc1554611fee44c2e540759

[OpenStack Infra (hudson-openstack)]

This issue was fixed in the openstack/tripleo-heat-templates 7.0.0.0b1 development milestone.