mesos git commit: Updated operational guide to document standalone to HA transition.

[bm...@apache.org]

Repository: mesos
Updated Branches:
  refs/heads/master 2ef6ef1ae -> b2877c106


Updated operational guide to document standalone to HA transition.

This methodology has been discuessed in the mailing list
and I've tested this several times with a dev clsuter.

Most recently, I've used this procedure to migrate a production
mesos cluster (with over 100 services and crons, and 6 mesos slaves)
from _standalone_ to `--quorum=2` with no issues.  It is probably
worth noting that the only framework in use on the cluster is Aurora.

Review: https://reviews.apache.org/r/35361


Project: http://git-wip-us.apache.org/repos/asf/mesos/repo
Commit: http://git-wip-us.apache.org/repos/asf/mesos/commit/b2877c10
Tree: http://git-wip-us.apache.org/repos/asf/mesos/tree/b2877c10
Diff: http://git-wip-us.apache.org/repos/asf/mesos/diff/b2877c10

Branch: refs/heads/master
Commit: b2877c106c1d12210c8e56b1f88c472b88a0d958
Parents: 2ef6ef1
Author: Michael Schenck <ms...@gmail.com>
Authored: Tue Jul 28 15:01:43 2015 -0700
Committer: Benjamin Mahler <be...@gmail.com>
Committed: Tue Jul 28 15:10:03 2015 -0700

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 docs/operational-guide.md | 8 +++++++-
 1 file changed, 7 insertions(+), 1 deletion(-)
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http://git-wip-us.apache.org/repos/asf/mesos/blob/b2877c10/docs/operational-guide.md
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diff --git a/docs/operational-guide.md b/docs/operational-guide.md
index 6347fca..ef81db6 100644
--- a/docs/operational-guide.md
+++ b/docs/operational-guide.md
@@ -31,6 +31,13 @@ The following steps indicate how to increment the quorum size, using 3 -> 5 mast
 
 To increase the quorum by N, repeat this process to increment the quorum size N times.
 
+NOTE: Currently, moving out of a single master setup requires wiping the replicated log
+state and starting fresh. This will wipe all persistent data (e.g. slaves, maintenance
+information, quota information, etc). To move from 1 master to 3 masters:
+
+1. Stop the standalone master.
+2. Remove the replicated log data (`replicated_log` under the `--work_dir`).
+3. Start the original master and two new masters with `--quorum=2`
 
 ### Decreasing the quorum size
 
@@ -42,6 +49,5 @@ The following steps indicate how to decrement the quorum size, using 5 -> 3 mast
 
 To decrease the quorum by N, repeat this process to decrement the quorum size N times.
 
-
 ### Replacing a master
 Please see the NOTE section above. So long as the failed master is guaranteed to not re-join the ensemble, it is safe to start a new master _with an empty log_ and allow it to catch up.