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1 | a8083063 | Iustin Pop | <!doctype refentry PUBLIC "-//OASIS//DTD DocBook V4.1//EN" [ |
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2 | a8083063 | Iustin Pop | |
3 | a8083063 | Iustin Pop | <!-- Fill in your name for FIRSTNAME and SURNAME. --> |
4 | a8083063 | Iustin Pop | <!-- Please adjust the date whenever revising the manpage. --> |
5 | 320d986d | Iustin Pop | <!ENTITY dhdate "<date>February 11, 2009</date>"> |
6 | a8083063 | Iustin Pop | <!-- SECTION should be 1-8, maybe w/ subsection other parameters are |
7 | a8083063 | Iustin Pop | allowed: see man(7), man(1). --> |
8 | a8083063 | Iustin Pop | <!ENTITY dhsection "<manvolnum>8</manvolnum>"> |
9 | a8083063 | Iustin Pop | <!ENTITY dhucpackage "<refentrytitle>ganeti-watcher</refentrytitle>"> |
10 | a8083063 | Iustin Pop | <!ENTITY dhpackage "ganeti-watcher"> |
11 | a8083063 | Iustin Pop | |
12 | a8083063 | Iustin Pop | <!ENTITY debian "<productname>Debian</productname>"> |
13 | a8083063 | Iustin Pop | <!ENTITY gnu "<acronym>GNU</acronym>"> |
14 | a8083063 | Iustin Pop | <!ENTITY gpl "&gnu; <acronym>GPL</acronym>"> |
15 | a8083063 | Iustin Pop | <!ENTITY footer SYSTEM "footer.sgml"> |
16 | a8083063 | Iustin Pop | ]> |
17 | a8083063 | Iustin Pop | |
18 | a8083063 | Iustin Pop | <refentry> |
19 | a8083063 | Iustin Pop | <refentryinfo> |
20 | a8083063 | Iustin Pop | <copyright> |
21 | a8083063 | Iustin Pop | <year>2007</year> |
22 | 320d986d | Iustin Pop | <year>2008</year> |
23 | 320d986d | Iustin Pop | <year>2009</year> |
24 | a8083063 | Iustin Pop | <holder>Google Inc.</holder> |
25 | a8083063 | Iustin Pop | </copyright> |
26 | a8083063 | Iustin Pop | &dhdate; |
27 | a8083063 | Iustin Pop | </refentryinfo> |
28 | a8083063 | Iustin Pop | <refmeta> |
29 | a8083063 | Iustin Pop | &dhucpackage; |
30 | a8083063 | Iustin Pop | |
31 | a8083063 | Iustin Pop | &dhsection; |
32 | 320d986d | Iustin Pop | <refmiscinfo>ganeti 2.0</refmiscinfo> |
33 | a8083063 | Iustin Pop | </refmeta> |
34 | a8083063 | Iustin Pop | <refnamediv> |
35 | a8083063 | Iustin Pop | <refname>&dhpackage;</refname> |
36 | a8083063 | Iustin Pop | |
37 | a8083063 | Iustin Pop | <refpurpose>ganeti cluster watcher</refpurpose> |
38 | a8083063 | Iustin Pop | </refnamediv> |
39 | a8083063 | Iustin Pop | <refsynopsisdiv> |
40 | a8083063 | Iustin Pop | <cmdsynopsis> |
41 | a8083063 | Iustin Pop | <command>&dhpackage; </command> |
42 | a8083063 | Iustin Pop | |
43 | a8083063 | Iustin Pop | </cmdsynopsis> |
44 | a8083063 | Iustin Pop | </refsynopsisdiv> |
45 | a8083063 | Iustin Pop | <refsect1> |
46 | a8083063 | Iustin Pop | <title>DESCRIPTION</title> |
47 | a8083063 | Iustin Pop | |
48 | a8083063 | Iustin Pop | <para> |
49 | a8083063 | Iustin Pop | The <command>&dhpackage;</command> is a periodically run script |
50 | a8083063 | Iustin Pop | which is responsible for keeping the instances in the correct |
51 | 6328fea3 | Iustin Pop | status. It has two separate functions, one for the master node |
52 | 6328fea3 | Iustin Pop | and another one that runs on every node. |
53 | a8083063 | Iustin Pop | </para> |
54 | a8083063 | Iustin Pop | |
55 | 6328fea3 | Iustin Pop | <refsect2> |
56 | 6328fea3 | Iustin Pop | <title>Master operations</title> |
57 | f69dab6d | Iustin Pop | |
58 | 6328fea3 | Iustin Pop | <para> |
59 | 6328fea3 | Iustin Pop | Its primary function is to try to keep running all instances |
60 | 6328fea3 | Iustin Pop | which are marked as <emphasis>up</emphasis> in the configuration |
61 | 6328fea3 | Iustin Pop | file, by trying to start them a limited number of times. |
62 | 6328fea3 | Iustin Pop | </para> |
63 | a8083063 | Iustin Pop | |
64 | 6328fea3 | Iustin Pop | <para> |
65 | 6328fea3 | Iustin Pop | Its other function is to <quote>repair</quote> DRBD links by |
66 | 6328fea3 | Iustin Pop | reactivating the block devices of instances which have |
67 | 6328fea3 | Iustin Pop | secondaries on nodes that have been rebooted. |
68 | 6328fea3 | Iustin Pop | </para> |
69 | 6328fea3 | Iustin Pop | |
70 | 6328fea3 | Iustin Pop | </refsect2> |
71 | 6328fea3 | Iustin Pop | |
72 | 6328fea3 | Iustin Pop | <refsect2> |
73 | 6328fea3 | Iustin Pop | |
74 | 6328fea3 | Iustin Pop | <title>Node operations</title> |
75 | 6328fea3 | Iustin Pop | |
76 | 6328fea3 | Iustin Pop | <para> |
77 | 6328fea3 | Iustin Pop | The watcher will restart any down daemons that are appropriate |
78 | 6328fea3 | Iustin Pop | for the current node. |
79 | 6328fea3 | Iustin Pop | </para> |
80 | 6328fea3 | Iustin Pop | |
81 | 6328fea3 | Iustin Pop | <para> |
82 | 6328fea3 | Iustin Pop | In addition, it will execute any scripts which exist under the |
83 | 6328fea3 | Iustin Pop | <quote>watcher</quote> directory in the ganeti hooks directory |
84 | 6328fea3 | Iustin Pop | (@SYSCONFDIR@/ganeti/hooks). This should be used for |
85 | 6328fea3 | Iustin Pop | lightweight actions, like starting any extra daemons. |
86 | 6328fea3 | Iustin Pop | </para> |
87 | 6328fea3 | Iustin Pop | |
88 | 6328fea3 | Iustin Pop | <para> |
89 | 6328fea3 | Iustin Pop | If the cluster |
90 | 6328fea3 | Iustin Pop | parameter <literal>maintain_node_health</literal> is enabled, |
91 | 6328fea3 | Iustin Pop | then the watcher will also shutdown instances and DRBD devices |
92 | 6328fea3 | Iustin Pop | if the node is declared as offline by known master candidates. |
93 | 6328fea3 | Iustin Pop | </para> |
94 | 6328fea3 | Iustin Pop | |
95 | 6328fea3 | Iustin Pop | <para> |
96 | 6328fea3 | Iustin Pop | The watcher does synchronous queries but will submit jobs for |
97 | 6328fea3 | Iustin Pop | executing the changes. Due to locking, it could be that the jobs |
98 | 6328fea3 | Iustin Pop | execute much later than the watcher executes them. |
99 | 6328fea3 | Iustin Pop | </para> |
100 | 6328fea3 | Iustin Pop | |
101 | 6328fea3 | Iustin Pop | </refsect2> |
102 | 6328fea3 | Iustin Pop | |
103 | 6328fea3 | Iustin Pop | |
104 | 6328fea3 | Iustin Pop | </refsect1> |
105 | 6328fea3 | Iustin Pop | |
106 | 6328fea3 | Iustin Pop | <refsect1> |
107 | 6328fea3 | Iustin Pop | <title>FILES</title> |
108 | a8083063 | Iustin Pop | |
109 | a8083063 | Iustin Pop | <para> |
110 | 96b9071c | Iustin Pop | The command has a state file located at |
111 | 6328fea3 | Iustin Pop | <filename>@LOCALSTATEDIR@/lib/ganeti/watcher.data</filename> |
112 | 6328fea3 | Iustin Pop | (only used on the master) and a log file at |
113 | 96b9071c | Iustin Pop | <filename>@LOCALSTATEDIR@/log/ganeti/watcher.log</filename>. Removal of |
114 | 96b9071c | Iustin Pop | either file will not affect correct operation; the removal of |
115 | 96b9071c | Iustin Pop | the state file will just cause the restart counters for the |
116 | 96b9071c | Iustin Pop | instances to reset to zero. |
117 | a8083063 | Iustin Pop | </para> |
118 | a8083063 | Iustin Pop | |
119 | a8083063 | Iustin Pop | </refsect1> |
120 | a8083063 | Iustin Pop | |
121 | a8083063 | Iustin Pop | &footer; |
122 | a8083063 | Iustin Pop | |
123 | a8083063 | Iustin Pop | </refentry> |
124 | a8083063 | Iustin Pop | |
125 | a8083063 | Iustin Pop | <!-- Keep this comment at the end of the file |
126 | a8083063 | Iustin Pop | Local variables: |
127 | a8083063 | Iustin Pop | mode: sgml |
128 | a8083063 | Iustin Pop | sgml-omittag:t |
129 | a8083063 | Iustin Pop | sgml-shorttag:t |
130 | a8083063 | Iustin Pop | sgml-minimize-attributes:nil |
131 | a8083063 | Iustin Pop | sgml-always-quote-attributes:t |
132 | a8083063 | Iustin Pop | sgml-indent-step:2 |
133 | a8083063 | Iustin Pop | sgml-indent-data:t |
134 | a8083063 | Iustin Pop | sgml-parent-document:nil |
135 | a8083063 | Iustin Pop | sgml-default-dtd-file:nil |
136 | a8083063 | Iustin Pop | sgml-exposed-tags:nil |
137 | a8083063 | Iustin Pop | sgml-local-catalogs:nil |
138 | a8083063 | Iustin Pop | sgml-local-ecat-files:nil |
139 | a8083063 | Iustin Pop | End: |
140 | a8083063 | Iustin Pop | --> |