[GEODE-10158] offheap can incorrectly disable or enable the query monitor

• Type: Bug
• Status: Closed
• Priority: Major
• Resolution: Fixed
• Fix Version/s: 1.15.0
• Component/s: offheap, querying
• Labels: pull-request-available
• Assignee: Darrel Schneider
• Reporter: Darrel Schneider
• Created: 23/Mar/22 19:38
• Updated: 22/Jun/22 20:46
• Resolved: 30/Mar/22 17:21

Description

Geode has a QueryMonitor that should be disabled if the resource manager's critical-heap-threshold is 0 and enabled if it is > 0.
But critical-offheap-threshold tries to also disable and enable the QueryMonitor. I think this is wrong since queries do not consume off-heap memory. QueryMonitor's relationship with the ResourceManager should only care about the critical-heap-threshold. The biggest risk is that this bug could cause the QueryMonitor to be disabled even though critical-heap-threshold is > 0. This would allow queries to consume heap memory when instead they should have failed with a LowMemoryException.

To workaround this issue make sure that if you are using offheap that you either leave both critical thresholds set to 0 or set both of them to a non-zero value.

A simple fix for this exists. Delete this one line from OffHeapMemoryMonitor:
cache.setQueryMonitorRequiredForResourceManager(criticalThreshold != 0);

A better fix would be to remove the InternalCache.setQueryMonitorRequiredForResourceManager method and instead have GemFireCacheImpl.getQueryMonitor method ask it's InternalResourceManager if it requires a QueryMonitor.

Issue Links

• links to: GitHub Pull Request #7483