Install-guide-OBS doesn't mention memcached configuration

[[e-mail]]

This bug report is also applying to Mitaka install guide.

Following the install guide for openSUSE [2] will probably result in a slow Horizon dashboard because of misconfigured memcached/keystone. Unlike the Ubuntu guide [1], which suggests to edit /etc/memcached.conf:

---cut here---
Edit the /etc/memcached.conf file and configure the service to use the management IP address of the controller node. This is to enable access by other nodes via the management network:

-l 10.0.0.11

Note:
Change the existing line that had -l 127.0.0.1.
---cut here---

there is no such section in OBS guide [2]. But in the Dashboard section [3] the configuration of the CACHE LOCATION refers to "host:port" and differs from default:

---cut here---
Configure the memcached session storage service:

SESSION_ENGINE = 'django.contrib.sessions.backends.cache'

CACHES = {
    'default': {
         'BACKEND': 'django.core.cache.backends.memcached.MemcachedCache',
         'LOCATION': 'controller:11211',
    }
}
---cut here---

This section is exactly the same as in ubuntu guide.
Either OBS guide should also recommend to change the file /etc/sysconfig/memcached for openSUSE/SLES, or the CACHE LOCATION should be changed to 127.0.0.1:11211 (default).

Due to this mismatch we were facing major performance issues in Horizon dashboard, we filed a bug for that [4].

[1] https://docs.openstack.org/newton/install-guide-ubuntu/environment-memcached.html
[2] https://docs.openstack.org/newton/install-guide-obs/environment-memcached.html
[3] https://docs.openstack.org/newton/install-guide-obs/horizon-install.html#install-and-configure-components
[4] https://bugs.launchpad.net/horizon/+bug/1587777

This bug tracker is for errors with the documentation, use the following as a template and remove or add fields as you see fit. Convert [ ] into [x] to check boxes:

- [x] This doc is inaccurate in this way: Missing memcached configuration for OBS guide
- [ ] This is a doc addition request.
- [ ] I have a fix to the document that I can paste below including example: input and output.

If you have a troubleshooting or support issue, use the following resources:

 - Ask OpenStack: http://ask.openstack.org
 - The mailing list: http://lists.openstack.org
 - IRC: 'openstack' channel on Freenode

-----------------------------------
Release: 0.1 on 2017-04-13 04:37
SHA: 87f79c69861fd806d0b8e6f66aa54d935b396903
Source: http://git.openstack.org/cgit/openstack/openstack-manuals/tree/doc/install-guide/source/horizon-install.rst
URL: https://docs.openstack.org/newton/install-guide-obs/horizon-install.html

[Lance Bragstad (lbragstad)]

It appears that this is specific to memcache configuration and not keystone configuration. In keystone, we use oslo.cache for global caching settings [0]. From there we implement caching specific to each subsystem, but I don't see either referenced in the report. Just to confirm, the negative impact in performance is due only to memcache misconfiguration, correct?

[0] https://github.com/openstack/keystone/blob/c7ab7c567792bafddc61fff003910df159aea7a5/etc/keystone.conf.sample#L498

[[e-mail] (eblock)]

> Just to confirm, the negative impact in performance is due only to memcache misconfiguration

Yes, as soon as we changed the memcache_server back to localhost (to match with /etc/memcached.conf) the performance improved significantly.

Before we used oslo.cache for memcache, we had configured this:

[memcache]
servers = localhost:11211

but it didn't work, and I'm wondering why. The deprecation messages indicate that it will be removed in P release, so I expected it to work in our setup.

[OpenStack Infra (hudson-openstack)]

Fix proposed to branch: master
Review: https://review.openstack.org/458802

[OpenStack Infra (hudson-openstack)]

Reviewed: https://review.openstack.org/458802
Committed: https://git.openstack.org/cgit/openstack/openstack-manuals/commit/?id=405c4b125501d734bcae72724f296e1d9239dfea
Submitter: Jenkins
Branch: master

commit 405c4b125501d734bcae72724f296e1d9239dfea
Author: Alexandra Settle <email address hidden>
Date: Fri Apr 21 11:26:11 2017 +0100

    [install-guide] Adds memcached instructions to obs guide

    Change-Id: I1ee4e173054aa3707d2a3dd2616b0b5b98d96caa
    Closes-bug: 1682439

[OpenStack Infra (hudson-openstack)]

Fix proposed to branch: stable/newton
Review: https://review.openstack.org/486942

[OpenStack Infra (hudson-openstack)]

Fix proposed to branch: stable/ocata
Review: https://review.openstack.org/486943

[OpenStack Infra (hudson-openstack)]

Reviewed: https://review.openstack.org/486942
Committed: https://git.openstack.org/cgit/openstack/openstack-manuals/commit/?id=f4db37796a7cdd02157bd7bbedbf00eb01446f58
Submitter: Jenkins
Branch: stable/newton

commit f4db37796a7cdd02157bd7bbedbf00eb01446f58
Author: Alexandra Settle <email address hidden>
Date: Fri Apr 21 11:26:11 2017 +0100

    [install-guide] Adds memcached instructions to obs guide

    Change-Id: I1ee4e173054aa3707d2a3dd2616b0b5b98d96caa
    Closes-bug: 1682439
    (cherry picked from commit 405c4b125501d734bcae72724f296e1d9239dfea)

[OpenStack Infra (hudson-openstack)]

Reviewed: https://review.openstack.org/486943
Committed: https://git.openstack.org/cgit/openstack/openstack-manuals/commit/?id=1da0b1e00aa5f08b8ff326d5f3dfbdbe2269623b
Submitter: Jenkins
Branch: stable/ocata

commit 1da0b1e00aa5f08b8ff326d5f3dfbdbe2269623b
Author: Alexandra Settle <email address hidden>
Date: Fri Apr 21 11:26:11 2017 +0100

    [install-guide] Adds memcached instructions to obs guide

    Change-Id: I1ee4e173054aa3707d2a3dd2616b0b5b98d96caa
    Closes-bug: 1682439
    (cherry picked from commit 405c4b125501d734bcae72724f296e1d9239dfea)