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1 | c6702e5e | Iustin Pop | .TH HAIL 1 2009-03-23 htools "Ganeti H-tools" |
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2 | c6702e5e | Iustin Pop | .SH NAME |
3 | c6702e5e | Iustin Pop | hail \- Ganeti IAllocator plugin |
4 | c6702e5e | Iustin Pop | |
5 | c6702e5e | Iustin Pop | .SH SYNOPSIS |
6 | c6702e5e | Iustin Pop | .B hail |
7 | c6702e5e | Iustin Pop | .I "input-file" |
8 | c6702e5e | Iustin Pop | |
9 | c6702e5e | Iustin Pop | .B hail |
10 | c6702e5e | Iustin Pop | .B --version |
11 | c6702e5e | Iustin Pop | |
12 | c6702e5e | Iustin Pop | .SH DESCRIPTION |
13 | c6702e5e | Iustin Pop | hail is a Ganeti IAllocator plugin that allows automatic instance |
14 | c6702e5e | Iustin Pop | placement and automatic instance secondary node replacement using the |
15 | c6702e5e | Iustin Pop | same algorithm as \fBhbal\fR(1). |
16 | c6702e5e | Iustin Pop | |
17 | c6702e5e | Iustin Pop | The program takes input via a JSON-file containing current cluster |
18 | c6702e5e | Iustin Pop | state and the request details, and output (on stdout) a JSON-formatted |
19 | c6702e5e | Iustin Pop | response. In case of critical failures, the error message is printed |
20 | c6702e5e | Iustin Pop | on stderr and the exit code is changed to show failure. |
21 | c6702e5e | Iustin Pop | |
22 | c6702e5e | Iustin Pop | .SS ALGORITHM |
23 | c6702e5e | Iustin Pop | |
24 | c6702e5e | Iustin Pop | The program uses a simplified version of the hbal algorithm. |
25 | c6702e5e | Iustin Pop | |
26 | c6702e5e | Iustin Pop | For relocations, we try to change the secondary node of the instance |
27 | c6702e5e | Iustin Pop | to all the valid other nodes; the node which results in the best |
28 | c6702e5e | Iustin Pop | cluster score is chosen. |
29 | c6702e5e | Iustin Pop | |
30 | c6702e5e | Iustin Pop | For single-node allocations (non-mirrored instances), again we select |
31 | c6702e5e | Iustin Pop | the node which, when chosen as the primary node, gives the best score. |
32 | c6702e5e | Iustin Pop | |
33 | c6702e5e | Iustin Pop | For dual-node allocations (mirrored instances), we chose the best |
34 | c6702e5e | Iustin Pop | pair; this is the only choice where the algoritm is non-trivial |
35 | c6702e5e | Iustin Pop | with regard to cluster size. |
36 | c6702e5e | Iustin Pop | |
37 | c6702e5e | Iustin Pop | For all choices, the cluster scoring is identical to the hbal |
38 | c6702e5e | Iustin Pop | algorithm. |
39 | c6702e5e | Iustin Pop | |
40 | c6702e5e | Iustin Pop | .SH EXIT STATUS |
41 | c6702e5e | Iustin Pop | |
42 | c6702e5e | Iustin Pop | The exist status of the command will be zero, unless for some reason |
43 | c6702e5e | Iustin Pop | the algorithm fatally failed (e.g. wrong node or instance data). |
44 | c6702e5e | Iustin Pop | |
45 | c6702e5e | Iustin Pop | .SH SEE ALSO |
46 | c6702e5e | Iustin Pop | .BR hn1 "(1), " hscan "(1), " ganeti "(7), " gnt-instance "(8), " |
47 | c6702e5e | Iustin Pop | .BR gnt-node "(8)" |
48 | e2fa2baf | Iustin Pop | |
49 | e2fa2baf | Iustin Pop | .SH "COPYRIGHT" |
50 | e2fa2baf | Iustin Pop | .PP |
51 | e2fa2baf | Iustin Pop | Copyright (C) 2009 Google Inc. Permission is granted to copy, |
52 | e2fa2baf | Iustin Pop | distribute and/or modify under the terms of the GNU General Public |
53 | e2fa2baf | Iustin Pop | License as published by the Free Software Foundation; either version 2 |
54 | e2fa2baf | Iustin Pop | of the License, or (at your option) any later version. |
55 | e2fa2baf | Iustin Pop | .PP |
56 | e2fa2baf | Iustin Pop | On Debian systems, the complete text of the GNU General Public License |
57 | e2fa2baf | Iustin Pop | can be found in /usr/share/common-licenses/GPL. |