root / man / ganeti-confd.sgml @ 9b94905f
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<!doctype refentry PUBLIC "-//OASIS//DTD DocBook V4.1//EN" [ |
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<!-- Please adjust the date whenever revising the manpage. --> |
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<!ENTITY dhdate "<date>October 21, 2009</date>"> |
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<!-- SECTION should be 1-8, maybe w/ subsection other parameters are |
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allowed: see man(7), man(1). --> |
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<!ENTITY dhsection "<manvolnum>8</manvolnum>"> |
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<!ENTITY dhucpackage "<refentrytitle>ganeti-confd</refentrytitle>"> |
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<!ENTITY dhpackage "ganeti-confd"> |
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<!ENTITY debian "<productname>Debian</productname>"> |
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<!ENTITY gnu "<acronym>GNU</acronym>"> |
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<!ENTITY gpl "&gnu; <acronym>GPL</acronym>"> |
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<!ENTITY footer SYSTEM "footer.sgml"> |
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]> |
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|
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<refentry> |
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<refentryinfo> |
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<copyright> |
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<year>2009</year> |
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<holder>Google Inc.</holder> |
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</copyright> |
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&dhdate; |
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</refentryinfo> |
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<refmeta> |
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&dhucpackage; |
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|
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&dhsection; |
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<refmiscinfo>ganeti 2.1</refmiscinfo> |
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</refmeta> |
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<refnamediv> |
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<refname>&dhpackage;</refname> |
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|
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<refpurpose>ganeti conf daemon</refpurpose> |
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</refnamediv> |
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<refsynopsisdiv> |
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<cmdsynopsis> |
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<command>&dhpackage; </command> |
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<arg>-f</arg> |
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<arg>-d</arg> |
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|
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</cmdsynopsis> |
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</refsynopsisdiv> |
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<refsect1> |
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<title>DESCRIPTION</title> |
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|
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<para> |
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<command>&dhpackage;</command> is a daemon used to answer queries related |
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to the configuration of a Ganeti cluster. |
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</para> |
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|
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<para> |
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For testing purposes, you can give the <option>-f</option> |
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option and the program won't detach from the running terminal. |
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</para> |
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|
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<para> |
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Debug-level message can be activated by giving the |
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<option>-d</option> option. |
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</para> |
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<refsect2> |
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<title>ROLE</title> |
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<para> |
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The role of the conf daemon is to make sure we have a highly available |
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and very fast way to query cluster configuration values. This daemon is |
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automatically active on all master candidates, and so has no single |
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point of failure. It communicates via UDP so each query can easily be |
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sent to multiple servers, and it answers queries from a cached copy of |
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the config it keeps in memory, so no disk access is required to get an |
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answer. |
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</para> |
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|
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<para> |
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The config is reloaded from disk automatically when it changes, with a |
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rate limit of once per second. |
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</para> |
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|
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<para> |
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If the conf daemon is stopped on all nodes, its clients won't be able |
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to get query answers. |
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</para> |
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</refsect2> |
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|
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<refsect2> |
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<title>COMMUNICATION PROTOCOL</title> |
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<para> |
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The confd protocol is an HMAC authenticated json-encoded custom format, |
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over UDP. A client library is provided to make it easy to write |
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software to query confd. More information can be found in the Ganeti |
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2.1 design doc, and an example usage can be seen in the (external) nbma |
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daemon for ganeti. |
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</para> |
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</refsect2> |
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|
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</refsect1> |
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|
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&footer; |
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|
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</refentry> |
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<!-- Keep this comment at the end of the file |
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Local variables: |
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mode: sgml |
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sgml-omittag:t |
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sgml-shorttag:t |
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sgml-minimize-attributes:nil |
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sgml-always-quote-attributes:t |
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sgml-indent-step:2 |
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sgml-indent-data:t |
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sgml-parent-document:nil |
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sgml-default-dtd-file:nil |
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sgml-exposed-tags:nil |
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sgml-local-catalogs:nil |
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sgml-local-ecat-files:nil |
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End: |
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--> |