ganeti

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Ganeti.HTools.Cluster

Contents

Description

Implementation of cluster-wide logic.

This module holds all pure cluster-logic; I/O related functionality goes into the Main module for the individual binaries.

Synopsis

Types

data AllocDetails Source

Allocation details for an instance, specifying required number of nodes, and an optional group (name) to allocate to

Constructors

AllocDetails Int (Maybe String) 

Instances

data GenericAllocSolution a Source

Allocation/relocation solution.

Constructors

AllocSolution 

Fields

asFailures :: [FailMode]

Failure counts

asAllocs :: Int

Good allocation count

asSolution :: Maybe (GenericAllocElement a)

The actual allocation result

asLog :: [String]

Informational messages

type AllocResult = (FailStats, List, List, [Instance], [CStats])Source

Allocation results, as used in iterateAlloc and tieredAlloc.

type GenericAllocSolutionList a = [(Instance, GenericAllocSolution a)]Source

Type alias for easier handling.

type AllocNodes = Either [Ndx] [(Ndx, [Ndx])]Source

A type denoting the valid allocation mode/pairs.

For a one-node allocation, this will be a Left [Ndx], whereas for a two-node allocation, this will be a Right [(Ndx, [Ndx])]. In the latter case, the list is basically an association list, grouped by primary node and holding the potential secondary nodes in the sub-list.

emptyAllocSolution :: GenericAllocSolution aSource

The empty solution we start with when computing allocations.

data Table Source

The complete state for the balancing solution.

Constructors

Table List List Score [Placement] 

Instances

Show Table 

data CStats Source

Cluster statistics data type.

Constructors

CStats 

Fields

csFmem :: Integer

Cluster free mem

csFdsk :: Integer

Cluster free disk

csFspn :: Integer

Cluster free spindles

csAmem :: Integer

Cluster allocatable mem

csAdsk :: Integer

Cluster allocatable disk

csAcpu :: Integer

Cluster allocatable cpus

csMmem :: Integer

Max node allocatable mem

csMdsk :: Integer

Max node allocatable disk

csMcpu :: Integer

Max node allocatable cpu

csImem :: Integer

Instance used mem

csIdsk :: Integer

Instance used disk

csIspn :: Integer

Instance used spindles

csIcpu :: Integer

Instance used cpu

csTmem :: Double

Cluster total mem

csTdsk :: Double

Cluster total disk

csTspn :: Double

Cluster total spindles

csTcpu :: Double

Cluster total cpus

csVcpu :: Integer

Cluster total virtual cpus

csNcpu :: Double

Equivalent to csIcpu but in terms of physical CPUs, i.e. normalised used phys CPUs

csXmem :: Integer

Unnacounted for mem

csNmem :: Integer

Node own memory

csScore :: Score

The cluster score

csNinst :: Int

The total number of instances

Instances

Show CStats 

type AllocMethodSource

Arguments

 = List

Node list

-> List

Instance list

-> Maybe Int

Optional allocation limit

-> Instance

Instance spec for allocation

-> AllocNodes

Which nodes we should allocate on

-> [Instance]

Allocated instances

-> [CStats]

Running cluster stats

-> Result AllocResult

Allocation result

A simple type for allocation functions.

Utility functions

computeBadItems :: List -> List -> ([Node], [Instance])Source

Computes the pair of bad nodes and instances.

The bad node list is computed via a simple verifyN1 check, and the bad instance list is the list of primary and secondary instances of those nodes.

totalResources :: List -> CStatsSource

Compute the total free disk and memory in the cluster.

computeAllocationDelta :: CStats -> CStats -> AllocStatsSource

Compute the delta between two cluster state.

This is used when doing allocations, to understand better the available cluster resources. The return value is a triple of the current used values, the delta that was still allocated, and what was left unallocated.

Balancing functions

possibleMoves :: MirrorType -> Bool -> Bool -> Bool -> (Bool, Bool) -> Ndx -> [IMove]Source

doNextBalanceSource

Arguments

:: Table

The starting table

-> Int

Remaining length

-> Score

Score at which to stop

-> Bool

The resulting table and commands

Check if we are allowed to go deeper in the balancing.

tryBalanceSource

Arguments

:: AlgorithmOptions

Algorithmic options for balancing

-> Table

The starting table

-> Maybe Table

The resulting table and commands

Run a balance move.

Allocation functions

collapseFailures :: [FailMode] -> FailStatsSource

Build failure stats out of a list of failures.

concatAllocs :: Ord a => GenericAllocSolution a -> OpResult (GenericAllocElement a) -> GenericAllocSolution aSource

Update current Allocation solution and failure stats with new elements.

genericDescribeSolution :: (a -> String) -> GenericAllocSolution a -> StringSource

genericAnnotateSolution :: (a -> String) -> GenericAllocSolution a -> GenericAllocSolution aSource

Annotates a solution with the appropriate string.

genAllocNodesSource

Arguments

:: List

Group list

-> List

The node map

-> Int

The number of nodes required

-> Bool

Whether to drop or not unallocable nodes

-> Result AllocNodes

The (monadic) result

Generate the valid node allocation singles or pairs for a new instance.

tryAllocSource

Arguments

:: Monad m 
=> AlgorithmOptions 
-> List

The node list

-> List

The instance list

-> Instance

The instance to allocate

-> AllocNodes

The allocation targets

-> m AllocSolution

Possible solution list

Try to allocate an instance on the cluster.

solutionDescription :: (Group, Result (GenericAllocSolution a)) -> [String]Source

Given a group/result, describe it as a nice (list of) messages.

filterMGResults :: [(Group, Result (GenericAllocSolution a))] -> [(Group, GenericAllocSolution a)]Source

From a list of possibly bad and possibly empty solutions, filter only the groups with a valid result. Note that the result will be reversed compared to the original list.

sortMGResults :: Ord a => [(Group, GenericAllocSolution a)] -> [(Group, GenericAllocSolution a)]Source

Sort multigroup results based on policy and score.

hasRequiredNetworks :: Group -> Instance -> BoolSource

Determines if a group is connected to the networks required by the | instance.

filterValidGroups :: [(Group, (List, List))] -> Instance -> ([(Group, (List, List))], [String])Source

findBestAllocGroup :: AlgorithmOptions -> List -> List -> List -> Maybe [Gdx] -> Instance -> Int -> Result (Group, AllocSolution, [String])Source

tryMGAllocSource

Arguments

:: AlgorithmOptions 
-> List

The group list

-> List

The node list

-> List

The instance list

-> Instance

The instance to allocate

-> Int

Required number of nodes

-> Result AllocSolution

Possible solution list

Try to allocate an instance on a multi-group cluster.

tryGroupAllocSource

Arguments

:: AlgorithmOptions 
-> List

The group list

-> List

The node list

-> List

The instance list

-> String

The allocation group (name)

-> Instance

The instance to allocate

-> Int

Required number of nodes

-> Result AllocSolution

Solution

Try to allocate an instance to a group.

updateIlSource

Arguments

:: List

The original instance list

-> Maybe (GenericAllocElement a)

The result of the allocation attempt

-> List

The updated instance list

Calculate the new instance list after allocation solution.

extractNlSource

Arguments

:: List

The original node list

-> Maybe (GenericAllocElement a)

The result of the allocation attempt

-> List

The new node list

Extract the the new node list from the allocation solution.

allocListSource

Arguments

:: AlgorithmOptions 
-> List

The group list

-> List

The node list

-> List

The instance list

-> [(Instance, AllocDetails)]

The instance to allocate

-> AllocSolutionList

Possible solution list

-> Result (List, List, AllocSolutionList)

The final solution list

Try to allocate a list of instances on a multi-group cluster.

tryChangeGroupSource

Arguments

:: AlgorithmOptions 
-> List

The cluster groups

-> List

The node list (cluster-wide)

-> List

Instance list (cluster-wide)

-> [Gdx]

Target groups; if empty, any groups not being evacuated

-> [Idx]

List of instance (indices) to be evacuated

-> Result (List, List, EvacSolution) 

Change-group IAllocator mode main function.

This is very similar to tryNodeEvac, the only difference is that we don't choose as target group the current instance group, but instead:

  1. at the start of the function, we compute which are the target groups; either no groups were passed in, in which case we choose all groups out of which we don't evacuate instance, or there were some groups passed, in which case we use those
  2. for each instance, we use findBestAllocGroup to choose the best group to hold the instance, and then we do what tryNodeEvac does, except for this group instead of the current instance group.

Note that the correct behaviour of this function relies on the function nodeEvacInstance to be able to do correctly both intra-group and inter-group moves when passed the ChangeAll mode.

iterateAlloc :: AlgorithmOptions -> AllocMethodSource

Standard-sized allocation method.

This places instances of the same size on the cluster until we're out of space. The result will be a list of identically-sized instances.

tieredAlloc :: AlgorithmOptions -> AllocMethodSource

Tiered allocation method.

This places instances on the cluster, and decreases the spec until we can allocate again. The result will be a list of decreasing instance specs.

Formatting functions

computeMoves :: Instance -> String -> IMove -> String -> String -> (String, [String])Source

printSolutionLineSource

Arguments

:: List

The node list

-> List

The instance list

-> Int

Maximum node name length

-> Int

Maximum instance name length

-> Placement

The current placement

-> Int

The index of the placement in the solution

-> (String, [String]) 

Converts a placement to string format.

involvedNodesSource

Arguments

:: List

Instance list, used for retrieving the instance from its index; note that this must be the original instance list, so that we can retrieve the old nodes

-> Placement

The placement we're investigating, containing the new nodes and instance index

-> [Ndx]

Resulting list of node indices

Return the instance and involved nodes in an instance move.

Note that the output list length can vary, and is not required nor guaranteed to be of any specific length.

getMoves :: (Table, Table) -> [MoveJob]Source

From two adjacent cluster tables get the list of moves that transitions from to the other

mergeJobs :: ([JobSet], [Ndx]) -> MoveJob -> ([JobSet], [Ndx])Source

splitJobs :: [MoveJob] -> [JobSet]Source

Break a list of moves into independent groups. Note that this will reverse the order of jobs.

formatJob :: Int -> Int -> (Int, MoveJob) -> [String]Source

formatCmds :: [JobSet] -> StringSource

Given a list of commands, prefix them with gnt-instance and also beautify the display a little.

printNodes :: List -> [String] -> StringSource

Print the node list.

printInsts :: List -> List -> StringSource

Print the instance list.

Node group functions

instanceGroup :: List -> Instance -> Result GdxSource

Computes the group of an instance.

findSplitInstances :: List -> List -> [Instance]Source

Compute the list of badly allocated instances (split across node groups).