[GEODE-7434] Unnecessary object allocation and locking in GMSHealthMonitor.contactedBy

• Type: Bug
• Status: Closed
• Priority: Major
• Resolution: Fixed
• Fix Version/s: 1.12.0
• Component/s: benchmarks, membership
• Labels: performance
• Assignee: Ernest Burghardt
• Reporter: Jacob Barrett
• Created: 11/Nov/19 20:02
• Updated: 30/Mar/20 23:33
• Resolved: 27/Nov/19 16:34

Description

GMSHealthMonitor.contactedBy allocates a TimeStamp for every call but throws it away almost all of the time in the call to putIfAbsent. Additionally, putIfAbsent always brags a monitor on the hash segment resulting in unnecessary synchronization.

All with use of JavaWorkarounds.computeIfAbsent to avoid the locking and object allocation for the hot path where the entry already exists.

Benchmark profiling shows 77% of P2P reader threads spent waiting for this lock.

Issue Links

• links to: GitHub Pull Request #4309