openstack-manuals/doc/config-reference/compute/section_compute-conductor.xml
Tom Fifield e4aac82b07 Remove old references in prep for Icehouse
A standard pre-release patch, looking for any obsolete text to remove,
and references to newly unsupported releases to remove.

Feel free to update the patch if you find other things.

Review request: this patch touches many files in a small way.
Please try and focus on the small changes, and not the rest of the
file ... since many of them do need an edit  ;)

Change-Id: I383c51acf149bb6553ddfd33cad382f5dd15fe62
2014-04-11 08:13:54 -05:00

44 lines
2.4 KiB
XML

<?xml version="1.0" encoding="UTF-8"?>
<section xmlns="http://docbook.org/ns/docbook"
xmlns:xi="http://www.w3.org/2001/XInclude"
xmlns:xlink="http://www.w3.org/1999/xlink"
version="5.0"
xml:id="section_conductor">
<title>Conductor</title>
<para>The <systemitem class="service">nova-conductor</systemitem>
service enables OpenStack to function without compute nodes
accessing the database. Conceptually, it implements a new
layer on top of <systemitem class="service"
>nova-compute</systemitem>. It should not be deployed on
compute nodes, or else the security benefits of removing
database access from <systemitem class="service"
>nova-compute</systemitem> are negated. Just like
other nova services such as <systemitem class="service"
>nova-api</systemitem> or nova-scheduler, it can be scaled
horizontally. You can run multiple instances of <systemitem
class="service">nova-conductor</systemitem> on different
machines as needed for scaling purposes.</para>
<para>The methods exposed by <systemitem
class="service">nova-conductor</systemitem> are relatively
simple methods used by <systemitem class="service"
>nova-compute</systemitem> to offload its database
operations. Places where <systemitem class="service"
>nova-compute</systemitem> previously performed database
access are now talking to <systemitem class="service"
>nova-conductor</systemitem>. However, we have plans in
the medium to long term to move more and more of what is
currently in <systemitem class="service"
>nova-compute</systemitem> up to the <systemitem
class="service">nova-conductor</systemitem> layer. The
Compute service will start to look like a less intelligent
slave service to <systemitem class="service"
>nova-conductor</systemitem>. The conductor service will
implement long running complex operations, ensuring forward
progress and graceful error handling. This will be especially
beneficial for operations that cross multiple compute nodes,
such as migrations or resizes.</para>
<para>To customize the Conductor, use the configuration option settings
documented in <xref linkend="config_table_nova_conductor"/>.</para>
</section>