[CASSANDRA-13338] JMX: EstimatedPartitionCount / SnapshotSize are expensive

• Type: Improvement
• Status: Open
• Priority: Normal
• Resolution: Unresolved
• Component/s: Legacy/Observability
• Labels: lhf
• Complexity: Low Hanging Fruit
• Assignee: Stefan Miklosovic
• Reporter: Corentin Chary

Authors

Stefan Miklosovic

• Created: 16/Mar/17 12:58
• Updated: 12/Dec/22 16:04

Description

EstimatedPartitionCount / EstimatedRowCount / SnapshotSize seem particularly expensive. For example on our system org.apache.cassandra.metrics:type=ColumnFamily,name=SnapshotsSize can take as much as half a second.

All this cumulated means that export stats for all your tables (with metrics-graphite or jmx_exporter) is going to take quite some time.

We should certainly try to find the most expensive end points and see if there is a way to cache some of the values.

cc: rgerard

Issue Links

• is related to: CASSANDRA-16843 List snapshots of dropped tables
• relates to: CASSANDRA-17588 "Total TrueDiskSpaceUsed" computation does not include manifest and schema files
• relates to: CASSANDRA-18102 Add a virtual table to list snapshots
• relates to: CASSANDRA-18111 Centralize all snapshot operations to SnapshotManager and cache snapshots