openstack/devstack
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Apache Keystone Template: reduce the number of processes to 3

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Now Apache2 has 5 dedicated processes for Keystone Admin and 5 for
Keystone Public. As each Apache process consumes some memory and
we arbitrarly decided 5 was a good number more than 2 years ago,
maybe now (with the recent memory pressure we feel) is a good time
to reconcider.

With 5 processes our peakmem_tracker.py script reports a max RSS size
for the "wsgi:keystone-ad" and "wsgi:keystone-pu" processes of
2 (public and admin) * 5 (number of processes) * 90 Mo (RSS of each
process) = 900 Mo.

With 3 processes, the overall max RSS for Keystone is
2 * 3 * 90 = 540 Mo.

Note that this is RSS memory, but using the "smem" linux command on
my laptop, I noticed that the USS (Unique set size, i.e RSS excluding
shared memory) is around 80Mo per process. So reducing the number of
processes will actually reduce memory consumption.

Change-Id: Iba72d94aa15ecaa87c0115ad26d6bpeakmem_tracker62d5b3bea0a
This commit is contained in:
Jordan Pittier 2017-03-15 13:27:20 +01:00
parent 477c55866b
commit fe1d3d6a7b
1 changed files with 2 additions and 2 deletions
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4
files/apache-keystone.template
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@ -7,7 +7,7 @@ LogFormat "%h %l %u %t \"%r\" %>s %b \"%{Referer}i\" \"%{User-agent}i\" %D(us)"
</Directory>
<VirtualHost *:%PUBLICPORT%>
WSGIDaemonProcess keystone-public processes=5 threads=1 user=%USER% display-name=%{GROUP} %VIRTUALENV%
WSGIDaemonProcess keystone-public processes=3 threads=1 user=%USER% display-name=%{GROUP} %VIRTUALENV%
WSGIProcessGroup keystone-public
WSGIScriptAlias / %KEYSTONE_BIN%/keystone-wsgi-public
WSGIApplicationGroup %{GLOBAL}
@ -21,7 +21,7 @@ LogFormat "%h %l %u %t \"%r\" %>s %b \"%{Referer}i\" \"%{User-agent}i\" %D(us)"
</VirtualHost>
<VirtualHost *:%ADMINPORT%>
WSGIDaemonProcess keystone-admin processes=5 threads=1 user=%USER% display-name=%{GROUP} %VIRTUALENV%
WSGIDaemonProcess keystone-admin processes=3 threads=1 user=%USER% display-name=%{GROUP} %VIRTUALENV%
WSGIProcessGroup keystone-admin
WSGIScriptAlias / %KEYSTONE_BIN%/keystone-wsgi-admin
WSGIApplicationGroup %{GLOBAL}