doc: Mention the 3 processes that make up Hydra.

Dependencies

• [2] KBW3FDZ2 Merge remote branch 'remotes/origin/master'
• [3] RQ4SOPS3 whitespace commit
• [4] HN7JDKV3 doc: Mention SQLite.

Change contents

• replacement in doc/manual/installation.xml at line 172
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  − <title>Getting started</title>
  [2.3026]

  [2.3065]
  + <title>Getting Started</title>

  +
• replacement in doc/manual/installation.xml at line 175
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  − To start the Hydra webserver, execute:
  [2.3080]

  [2.3143]
  + To start the Hydra web server, execute:
• replacement in doc/manual/installation.xml at line 179
  [2.3190]→[2.3190:3328](∅→∅)
  − When the server is started, you can browse to <ulink>http://localhost:3000/</ulink> to start configuring your Hydra instance.
  [2.3190]

  [2.3328]
  + When the server is started, you can browse to

  + <ulink>http://localhost:3000/</ulink> to start configuring

  + your Hydra instance.
• replacement in doc/manual/installation.xml at line 183
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  − </section>
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  [2.3359]
  +

  + <para>

  + The <command>hydra_server.pl</command> command launches the

  + web server. There are two other processes that come into

  + play:
• replacement in doc/manual/installation.xml at line 189
  [2.3360]→[2.3360:3581](∅→∅)
  − <section>

  − <title>Example: PatchELF</title>

  − <para>

  − </para>

  −

  − <subsection>

  − <title>Defining jobsets</title>

  − <para>

  − </para>

  − </subsection>
  [2.3360]

  [2.3581]
  + <itemizedlist>

  + <listitem>

  + The <emphasis>evaluator</emphasis> is responsible for

  + peridically evaluating job sets, checking out their

  + dependencies off their version control systems (VCS),

  + and queueing new builds if the result of the evaluation

  + changed. It is launched by the

  + <command>hydra_evaluator.pl</command> command.

  + </listitem>

  + <listitem>

  + The <emphasis>queue runner</emphasis> launches builds

  + (using Nix) as they are queued by the evaluator,

  + scheduling them onto the configured Nix hosts. It is

  + launched using the

  + <command>hydra_queue_runner.pl</command> command.

  + </listitem>

  + </itemizedlist>
• replacement in doc/manual/installation.xml at line 207
  [2.3582]→[2.3582:3706](∅→∅)
  − <subsection>

  − <title>Creating views</title>

  − <para>

  − </para>

  − </subsection>
  [2.3582]

  [2.3724]
  + All three processes must be running for Hydra to be fully

  + functional, though it's possible to temporarily stop any one

  + of them for maintenance purposes, for instance.

  + </para>

  +
• edit in doc/manual/installation.xml at line 215
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  −