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

The complete state for the balancing solution.

Cluster statistics data type.

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.

Allocation results, as used in iterateAlloc and tieredAlloc.

A simple type for allocation functions.

Type alias for easier handling.

Compute the total free disk and memory in the cluster.

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.

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

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.

Converts a placement to string format.

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

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.

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

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

Print the node list.

Print the instance list.

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

Run a balance move.

Convert a placement into a list of OpCodes (basically a job).

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

Try to allocate an instance on the cluster.

Try to allocate an instance to a group.

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

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.

Sort multigroup results based on policy and score.

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.

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

A speed-up version of iterateAllocSmallStep.

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.

Computes the group of an instance.

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