[CASSANDRA-5537] Reduce Empty Map allocations in Directory.SSTableLister

• Type: Improvement
• Status: Resolved
• Priority: Low
• Resolution: Won't Fix
• Fix Version/s: 2.0 beta 1
• Assignee: David Brosius
• Reporter: David Brosius

Authors

David Brosius

• Created: 06/May/13 06:10
• Updated: 16/Apr/19 09:32
• Resolved: 06/May/13 15:01

Description

SSTableLister allocates HashMaps consistently that are very often not used.

See output: http://pastebin.com/Ky4hUn5X

Format is

Type Date SourceLine CollectionSize NumBuckets NumBucketsUsed

The snapshot is taken after the size of the collection hasn't changed for 5 seconds.

Postpone creation of hashmap until you need it.