Parallel GS threads should call Hyperspace iterator one at a time

[exalate-issue-sync]

In the GridSearch class, there is

{code:java}
private MP getNextModelParams(final HyperSpaceWalker.HyperSpaceIterator hyperSpaceWalker, final Model model, final Grid grid){
MP params = null;

  while (params == null) {
    if (hyperSpaceWalker.hasNext(model)) {
      params = hyperSpaceWalker.nextModelParameters(model);
      final Key modelKey = grid.getModelKey(params.checksum(IGNORED_FIELDS_PARAM_HASH));
      if(modelKey != null){
        params = null;
      }
    } else {
      break;
    }
  }

  return params;
}

}
{code}
method which calls hyperspace iterator and asks for next model params. It is perfectly possible (but highly improbable) for two threads accessing the nextModelParams method to obtain the same parameters.

Solution is to use mutually exclusive access.

[h2o-ops]

JIRA Issue Migration Info

Jira Issue: PUBDEV-7197
Assignee: Pavel Pscheidl
Reporter: Pavel Pscheidl
State: Resolved
Fix Version: 3.28.0.2
Attachments: N/A
Development PRs: Available

Linked PRs from JIRA

#4207