From d52d41de85348cbf9c18156e122718471d4bbf1f Mon Sep 17 00:00:00 2001
From: Iustin Pop <iustin@google.com>
Date: Thu, 7 Jul 2011 00:13:27 +0200
Subject: [PATCH] htools: add node-evacuation of DRBD all nodes
This is much more complicated than either change primary (which is
trivial) and change secondary (which is also simple).
The main strategy is:
- choose a new secondary (that will become the final primary) and
replace-disks to it
- failover
- choose a new secondary again (this will be the final secondary)
However, if the original primary was offline, then we first have to
failover to the secondary of the instance.
Note: currently this evacuation mode, while producing correct
evacuation results, does not result in optimal placement of the
instance; it will need attention and possibly an algorithm change.
Signed-off-by: Iustin Pop <iustin@google.com>
Reviewed-by: Guido Trotter <ultrotter@google.com>
---
htools/Ganeti/HTools/Cluster.hs | 43 ++++++++++++++++++++++++++++++---
1 file changed, 40 insertions(+), 3 deletions(-)
diff --git a/htools/Ganeti/HTools/Cluster.hs b/htools/Ganeti/HTools/Cluster.hs
index 27e7a9da6..ecd6c91cf 100644
--- a/htools/Ganeti/HTools/Cluster.hs
+++ b/htools/Ganeti/HTools/Cluster.hs
@@ -939,9 +939,46 @@ nodeEvacInstance nl il ChangeSecondary
ops = iMoveToJob nl' il' idx (ReplaceSecondary ndx)
return (nl', il', ops)
-nodeEvacInstance _ _ _ (Instance.Instance
- {Instance.diskTemplate = DTDrbd8}) _ =
- fail "DRBD relocations not implemented yet"
+nodeEvacInstance nl il ChangeAll
+ inst@(Instance.Instance {Instance.diskTemplate = DTDrbd8})
+ avail_nodes =
+ do
+ let primary = Container.find (Instance.pNode inst) nl
+ idx = Instance.idx inst
+ gdx = instancePriGroup nl inst
+ no_nodes = Left "no nodes available"
+ -- if the primary is offline, then we first failover
+ (nl1, inst1, ops1) <-
+ if Node.offline primary
+ then do
+ (nl', inst', _, _) <-
+ annotateResult "Failing over to the secondary" $
+ opToResult $ applyMove nl inst Failover
+ return (nl', inst', [Failover])
+ else return (nl, inst, [])
+ -- we now need to execute a replace secondary to the future
+ -- primary node
+ (nl2, inst2, _, new_pdx) <- annotateResult "Searching for a new primary" $
+ eitherToResult $
+ foldl' (evacDrbdSecondaryInner nl1 inst1 gdx)
+ no_nodes avail_nodes
+ let ops2 = ReplaceSecondary new_pdx:ops1
+ -- since we chose the new primary, we remove it from the list of
+ -- available nodes
+ let avail_nodes_sec = new_pdx `delete` avail_nodes
+ -- we now execute another failover, the primary stays fixed now
+ (nl3, inst3, _, _) <- annotateResult "Failing over to new primary" $
+ opToResult $ applyMove nl2 inst2 Failover
+ let ops3 = Failover:ops2
+ -- and finally another replace secondary, to the final secondary
+ (nl4, inst4, _, new_sdx) <-
+ annotateResult "Searching for a new secondary" $
+ eitherToResult $
+ foldl' (evacDrbdSecondaryInner nl3 inst3 gdx) no_nodes avail_nodes_sec
+ let ops4 = ReplaceSecondary new_sdx:ops3
+ il' = Container.add idx inst4 il
+ ops = concatMap (iMoveToJob nl4 il' idx) $ reverse ops4
+ return (nl4, il', ops)
-- | Inner fold function for changing secondary of a DRBD instance.
--
--
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