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author | Humble Devassy Chirammal <hchiramm@redhat.com> | 2015-07-23 18:07:08 +0530 |
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committer | Kaleb KEITHLEY <kkeithle@redhat.com> | 2015-08-05 04:49:00 -0700 |
commit | a0919d638a889f03a5bd804cf4c3a63084680fce (patch) | |
tree | 72d519341747cfc82afcc06c313f9b92018bece0 /doc/features/server-quorum.md | |
parent | 3403370ebeaf16567b79022c6ac48b2e0cd50db5 (diff) |
Removing glusterfs features doc from glusterfs repo
According to the new workflow defined for glusterfs documentation,
the features are maintained at https://github.com/gluster/glusterfs-specs.
Removing the features dir from the doc repo as per,
https://www.mail-archive.com/gluster-users@gluster.org/msg21168.html
Change-Id: I2f1219c49ef933f6b89a55f2238787d8565d80b6
BUG: 1206539
Signed-off-by: Humble Devassy Chirammal <hchiramm@redhat.com>
Reviewed-on: http://review.gluster.org/11749
Tested-by: NetBSD Build System <jenkins@build.gluster.org>
Tested-by: Gluster Build System <jenkins@build.gluster.com>
Reviewed-by: Prashanth Pai <ppai@redhat.com>
Reviewed-by: Humble Devassy Chirammal <humble.devassy@gmail.com>
Reviewed-by: Kaleb KEITHLEY <kkeithle@redhat.com>
Diffstat (limited to 'doc/features/server-quorum.md')
-rw-r--r-- | doc/features/server-quorum.md | 44 |
1 files changed, 0 insertions, 44 deletions
diff --git a/doc/features/server-quorum.md b/doc/features/server-quorum.md deleted file mode 100644 index 7b20084cea8..00000000000 --- a/doc/features/server-quorum.md +++ /dev/null @@ -1,44 +0,0 @@ -# Server Quorum - -Server quorum is a feature intended to reduce the occurrence of "split brain" -after a brick failure or network partition. Split brain happens when different -sets of servers are allowed to process different sets of writes, leaving data -in a state that can not be reconciled automatically. The key to avoiding split -brain is to ensure that there can be only one set of servers - a quorum - that -can continue handling writes. Server quorum does this by the brutal but -effective means of forcing down all brick daemons on cluster nodes that can no -longer reach enough of their peers to form a majority. Because there can only -be one majority, there can be only one set of bricks remaining, and thus split -brain can not occur. - -## Options - -Server quorum is controlled by two parameters: - - * **cluster.server-quorum-type** - - This value may be "server" to indicate that server quorum is enabled, or - "none" to mean it's disabled. - - * **cluster.server-quorum-ratio** - - This is the percentage of cluster nodes that must be up to maintain quorum. - More precisely, this percentage of nodes *plus one* must be up. - -Note that these are cluster-wide flags. All volumes served by the cluster will -be affected. Once these values are set, quorum actions - starting or stopping -brick daemons in response to node or network events - will be automatic. - -## Best Practices - -If a cluster with an even number of nodes is split exactly down the middle, -neither half can have quorum (which requires **more than** half of the total). -This is particularly important when N=2, in which case the loss of either node -leads to loss of quorum. Therefore, it is highly advisable to ensure that the -cluster size is three or greater. The "extra" node in this case need not have -any bricks or serve any data. It need only be present to preserve the notion -of a quorum majority less than the entire cluster membership, allowing the -cluster to survive the loss of a single node without losing quorum. - - - |