| Safe Haskell | None |
|---|
Ganeti.HTools.Cluster.Evacuate
Description
Implementation of node evacuation
Synopsis
- data EvacSolution = EvacSolution {}
- emptyEvacSolution :: EvacSolution
- reverseEvacSolution :: EvacSolution -> EvacSolution
- type EvacInnerState = Either String (List, Instance, Score, Ndx)
- failOnSecondaryChange :: MonadFail m => EvacMode -> DiskTemplate -> m ()
- evacOneNodeInner :: AlgorithmOptions -> List -> Instance -> Gdx -> (Ndx -> IMove) -> EvacInnerState -> Ndx -> EvacInnerState
- evacOneNodeOnly :: AlgorithmOptions -> List -> List -> Instance -> Gdx -> [Ndx] -> Result (List, List, [OpCode])
- evacDrbdAllInner :: AlgorithmOptions -> List -> List -> Instance -> Gdx -> (Ndx, Ndx) -> Result (List, List, [OpCode], Score)
- nodeEvacInstance :: AlgorithmOptions -> List -> List -> EvacMode -> Instance -> Gdx -> [Ndx] -> Result (List, List, [OpCode])
- updateEvacSolution :: (List, List, EvacSolution) -> Idx -> Result (List, List, [OpCode]) -> (List, List, EvacSolution)
- nodesToEvacuate :: List -> EvacMode -> [Idx] -> IntSet
- tryNodeEvac :: AlgorithmOptions -> List -> List -> List -> EvacMode -> [Idx] -> Result (List, List, EvacSolution)
Documentation
data EvacSolution Source #
Node evacuation/group change iallocator result type. This result type consists of actual opcodes (a restricted subset) that are transmitted back to Ganeti.
Constructors
| EvacSolution | |
Instances
| Show EvacSolution # | |
Defined in Ganeti.HTools.Cluster.Evacuate Methods showsPrec :: Int -> EvacSolution -> ShowS show :: EvacSolution -> String showList :: [EvacSolution] -> ShowS | |
emptyEvacSolution :: EvacSolution Source #
The empty evac solution.
reverseEvacSolution :: EvacSolution -> EvacSolution Source #
Reverses an evacuation solution.
Rationale: we always concat the results to the top of the lists, so for proper jobset execution, we should reverse all lists.
type EvacInnerState = Either String (List, Instance, Score, Ndx) Source #
A simple type for the running solution of evacuations.
failOnSecondaryChange :: MonadFail m => EvacMode -> DiskTemplate -> m () Source #
Function which fails if the requested mode is change secondary.
This is useful since except DRBD, no other disk template can execute change secondary; thus, we can just call this function instead of always checking for secondary mode. After the call to this function, whatever mode we have is just a primary change.
Arguments
| :: AlgorithmOptions | |
| -> List | Cluster node list |
| -> 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 |
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.
Arguments
| :: AlgorithmOptions | |
| -> List | The node list (cluster-wide) |
| -> List | Instance list (cluster-wide) |
| -> Instance | The instance to be evacuated |
| -> Gdx | The group we're targetting |
| -> [Ndx] | The list of available nodes for allocation |
| -> Result (List, List, [OpCode]) |
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. It folds the inner function evacOneNodeInner
over the list of available nodes, which results in the best choice
for relocation.
Arguments
| :: AlgorithmOptions | |
| -> List | Cluster node list |
| -> List | Cluster instance list |
| -> Instance | The instance to be moved |
| -> Gdx | The target group index (which can differ from the current group of the instance) |
| -> (Ndx, Ndx) | Tuple of new primary/secondary nodes |
| -> Result (List, List, [OpCode], Score) |
Compute result of changing all nodes of a DRBD instance.
Given the target primary and secondary node (which might be in a
different group or not), this function will execute all the
required steps and assuming all operations succceed, will return
the modified node and instance lists, the opcodes needed for this
and the new group score.
Arguments
| :: AlgorithmOptions | |
| -> List | The node list (cluster-wide) |
| -> List | Instance list (cluster-wide) |
| -> EvacMode | The evacuation mode |
| -> Instance | The instance to be evacuated |
| -> Gdx | The group we're targetting |
| -> [Ndx] | The list of available nodes for allocation |
| -> Result (List, List, [OpCode]) |
Run evacuation for a single instance.
Note: this function should correctly execute both intra-group
evacuations (in all modes) and inter-group evacuations (in the
ChangeAll mode). Of course, this requires that the correct list
of target nodes is passed.
updateEvacSolution :: (List, List, EvacSolution) -> Idx -> Result (List, List, [OpCode]) -> (List, List, EvacSolution) Source #
Updates the evac solution with the results of an instance evacuation.
Arguments
| :: List | The cluster-wide instance list |
| -> EvacMode | The evacuation mode we're using |
| -> [Idx] | List of instance indices being evacuated |
| -> IntSet | Set of node indices |
Compute the list of nodes that are to be evacuated, given a list of instances and an evacuation mode.
Arguments
| :: AlgorithmOptions | |
| -> List | The cluster groups |
| -> List | The node list (cluster-wide, not per group) |
| -> List | Instance list (cluster-wide) |
| -> EvacMode | The evacuation mode |
| -> [Idx] | List of instance (indices) to be evacuated |
| -> Result (List, List, EvacSolution) |
Node-evacuation IAllocator mode main function.