The function is now generic, so let's rename it and cleanup/improve
the docstrings.
---
htools/Ganeti/HTools/Cluster.hs | 28 +++++++++++++++++-----------
1 files changed, 17 insertions(+), 11 deletions(-)
diff --git a/htools/Ganeti/HTools/Cluster.hs b/htools/Ganeti/HTools/Cluster.hs
index 9878ba4..11b7cae 100644
--- a/htools/Ganeti/HTools/Cluster.hs
+++ b/htools/Ganeti/HTools/Cluster.hs
@@ -955,7 +955,9 @@ nodeEvacInstance nl il ChangeAll
-- | Generic function for changing one node of an instance.
--
-- This is similar to 'nodeEvacInstance' but will be used in a few of
--- its sub-patterns.
+-- its sub-patterns. It folds the inner function 'evacOneNodeInner'
+-- over the list of available nodes, which results in the best choice
+-- for relocation.
evacOneNodeOnly :: Node.List -- ^ The node list (cluster-wide)
-> Instance.List -- ^ Instance list (cluster-wide)
-> Instance.Instance -- ^ The instance to be evacuated
@@ -970,28 +972,32 @@ evacOneNodeOnly nl il inst gdx avail_nodes = do
MirrorExternal -> Ok FailoverToAny
(nl', inst', _, ndx) <- annotateResult "Can't find any good node" $
eitherToResult $
- foldl' (evacDrbdSecondaryInner nl inst gdx op_fn)
+ foldl' (evacOneNodeInner nl inst gdx op_fn)
(Left "no nodes available") avail_nodes
let idx = Instance.idx inst
il' = Container.add idx inst' il
ops = iMoveToJob nl' il' idx (op_fn ndx)
return (nl', il', ops)
--- | Inner fold function for changing secondary of a DRBD instance.
+-- | Inner fold function for changing one node of an instance.
+--
+-- Depending on the instance disk template, this will either change
+-- the secondary (for DRBD) or the primary node (for shared
+-- storage). However, the operation is generic otherwise.
--
-- The running solution is either a @Left String@, which means we
-- don't have yet a working solution, or a @Right (...)@, which
-- represents a valid solution; it holds the modified node list, the
-- modified instance (after evacuation), the score of that solution,
-- and the new secondary node index.
-evacDrbdSecondaryInner :: Node.List -- ^ Cluster node list
- -> Instance.Instance -- ^ Instance being evacuated
- -> Gdx -- ^ The group index of the instance
- -> (Ndx -> IMove) -- ^ Operation constructor
- -> EvacInnerState -- ^ Current best solution
- -> Ndx -- ^ Node we're evaluating as new secondary
- -> EvacInnerState -- ^ New best solution
-evacDrbdSecondaryInner nl inst gdx op_fn accu ndx =
+evacOneNodeInner :: Node.List -- ^ Cluster node list
+ -> Instance.Instance -- ^ Instance being evacuated
+ -> Gdx -- ^ The group index of the instance
+ -> (Ndx -> IMove) -- ^ Operation constructor
+ -> EvacInnerState -- ^ Current best solution
+ -> Ndx -- ^ Node we're evaluating as target
+ -> EvacInnerState -- ^ New best solution
+evacOneNodeInner nl inst gdx op_fn accu ndx =
case applyMove nl inst (op_fn ndx) of
OpFail fm ->
case accu of
--
1.7.9.1
