added performance chapter

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Roland Gruber 2014-01-11 14:08:47 +00:00
parent ce5eb71111
commit fe3463b77a
1 changed files with 137 additions and 45 deletions

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@ -1201,7 +1201,7 @@ Have fun!
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<section>
<section id="general_settings">
<title>General settings</title>
<para>Here you can specify the LDAP server and some security
@ -8368,7 +8368,7 @@ objectclass: top
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<para><emphasis role="bold">Indices:</emphasis></para>
<para id="indices"><emphasis role="bold">Indices:</emphasis></para>
<para>Indices will improve the performance when searching for entries in
the LDAP directory. The following indices are recommended:</para>
@ -8647,7 +8647,7 @@ objectclass: top
service customisations.</para>
</appendix>
<appendix>
<appendix id="clustering">
<title>Clustering LAM</title>
<para>LAM is a web application based on PHP. Therefore, clustering is not
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<appendix>
<title>Troubleshooting</title>
<section>
<title>Functional issues</title>
<para><emphasis role="bold">Size limit</emphasis></para>
<para>You will get a message like "LDAP sizelimit exceeded, not all
entries are shown." when you hit the LDAP search limit. See the <link
linkend="size_limit_exceeded">OpenLDAP settings</link> to fix this.</para>
linkend="size_limit_exceeded">OpenLDAP settings</link> to fix
this.</para>
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</literallayout>
@ -8745,10 +8749,10 @@ objectclass: top
<para>This can be done by running "Tools" -&gt; "Tests" -&gt; "Schema
test" inside LAM.</para>
<para>If there are any object classes or attributes missing you will get a
notice. See <link linkend="a_schema">LDAP schema files</link> for a list
of used schemas. You may also want to deactive unused modules in your LAM
server profile (tab "Modules").</para>
<para>If there are any object classes or attributes missing you will get
a notice. See <link linkend="a_schema">LDAP schema files</link> for a
list of used schemas. You may also want to deactive unused modules in
your LAM server profile (tab "Modules").</para>
<screenshot>
<mediaobject>
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<para>After changing the configuration please restart OpenLDAP. It usually
uses /var/log/syslog for log output.</para>
<para>After changing the configuration please restart OpenLDAP. It
usually uses /var/log/syslog for log output.</para>
</section>
<section>
<title>Performance issues</title>
<para>LAM is tested to work with 10000 users with acceptable
performance. If you have a larger directory or slow hardware then here
are some points to increase performance.</para>
<literallayout>
</literallayout>
<para>The first step is to check if performance problems are caused by
the LAM web server or the LDAP server. Please check which machine
suffers from high system load (CPU/memory consumption).</para>
<para>High network latency may also be a problem. For large
installations please make sure that LAM web server and LDAP server are
located in the same building/server room.</para>
<para>If you run LAM on multiple nodes (DNS load balancing/hardware load
balancer) then also check the <link linkend="clustering">clustering
section</link>.</para>
<section>
<title>LDAP server</title>
<para><emphasis role="bold">Use indices</emphasis></para>
<para>Depending on the queries it may help to add some more indices on
the LDAP server. Depending on your LDAP software it may already
suggest indices in its log files. See <link
linkend="indices">here</link> for typical OpenLDAP indices.</para>
<literallayout>
</literallayout>
<para><emphasis role="bold">Reduce query results by splitting LDAP
management into multiple server profiles</emphasis></para>
<para>If you manage a very large directory then it might already be
separated into multiple subtrees (e.g. by country, subsidiary, ...).
Do not use a single LAM server profile to manage your whole directory.
Use different server profiles for each separated LDAP subtree where
possible (e.g. one for German users and one for French ones).</para>
<literallayout>
</literallayout>
<para><emphasis role="bold">Limit query results</emphasis></para>
<para>LAM allows to set an <ulink url="general_settings">LDAP search
limit</ulink> for each server profile. This will limit the number of
entries returned by your LDAP server. Use with caution because it can
cause problems (e.g. with automatic UID generation) when LAM is not
able to read all entries.</para>
</section>
<section>
<title>LAM web server</title>
<para><emphasis role="bold">Install a PHP
accelerator</emphasis></para>
<para>There are tools like <ulink
url="http://www.php.net/manual/en/book.apc.php">APC</ulink> (free) or
<ulink url="http://www.zend.com/en/products/server/">Zend
Server</ulink> (commercial) that provide caching of PHP pages to
improve performance. They will reduce the time for parsing the PHP
pages and IO load.</para>
<para>This is a simply way to enhance performance since APC is part of
most Linux distributions.</para>
<para>If you use APC then make sure that it uses enough memory (e.g.
"apc.shm_size=128M"). You can check the memory usage with the file
apc.php that is shipped with APC.</para>
<literallayout>
</literallayout>
<para><emphasis role="bold">Disable session
encryption</emphasis></para>
<para>LAM encrypts sensitive data in your session files. You can
prevent this by disabling the PHP MCrypt module (if installed).</para>
</section>
</section>
</appendix>
</book>