memcache by default is configured to use 95% of ram

[Alex Schultz]

Fuel had a similar issue see Bug 1439882. The memcached puppet module defaults to 95% of the total memory in the machine as the default memory value.

[centos@undercloud ~]$ cat /etc/sysconfig/memcached
PORT="11211"
USER="memcached"
MAXCONN="8192"
CACHESIZE="7431"
OPTIONS="-l 127.0.0.1 -U 11211 -t 4 >> /var/log/memcached.log 2>&1"
[centos@undercloud ~]$ free
              total used free shared buff/cache available
Mem: 8010560 7205748 280720 500 524092 480332
Swap: 0 0 0

This should be configurable via THT but we should opt for a reduced default amount.

[OpenStack Infra (hudson-openstack)]

Fix proposed to branch: master
Review: https://review.openstack.org/431042

[OpenStack Infra (hudson-openstack)]

Fix proposed to branch: master
Review: https://review.openstack.org/431045

[OpenStack Infra (hudson-openstack)]

Reviewed: https://review.openstack.org/431042
Committed: https://git.openstack.org/cgit/openstack/instack-undercloud/commit/?id=8222fe1c42214e8ae1374d2e990123a743b16a7e
Submitter: Jenkins
Branch: master

commit 8222fe1c42214e8ae1374d2e990123a743b16a7e
Author: Alex Schultz <email address hidden>
Date: Wed Feb 8 09:30:07 2017 -0700

    Reduce memcached memory usage

    By default memcache will be setup with 95% of the memory available in
    the system. We do not need this much memory assigned and it can lead to
    OOM killer issues. This change reduces the default configuration to 50%
    of the available memory instead.

    Change-Id: I21761e7f4d4d732237d8025c756a2f7a13575afa
    Partial-Bug: #1662941

[OpenStack Infra (hudson-openstack)]

Reviewed: https://review.openstack.org/431045
Committed: https://git.openstack.org/cgit/openstack/tripleo-heat-templates/commit/?id=97e0768dfae29caeb78acc6fe3427d01762315cf
Submitter: Jenkins
Branch: master

commit 97e0768dfae29caeb78acc6fe3427d01762315cf
Author: Alex Schultz <email address hidden>
Date: Wed Feb 8 09:37:05 2017 -0700

    Reduce memcached memory configuration

    Previously the memcached configuration was set to use the defaults which
    would be 95% of the avaiable ram in the system. This can lead to memory
    contention issues if memcache is heavily utilized. This change reduces
    the default to 50% and exposes the ability to tune this configuration.

    Change-Id: Ie8a48ff4cf509e93d7c1487813d5feed5e5131a4
    Closes-Bug: #1662941

[OpenStack Infra (hudson-openstack)]

This issue was fixed in the openstack/tripleo-heat-templates 6.0.0.0rc1 release candidate.