[CASSANDRA-8880] Add metrics to monitor the amount of tombstones created

• Type: Improvement
• Status: Open
• Priority: Low
• Resolution: Unresolved
• Fix Version/s: 2.1.x
• Labels: lhf metrics
• Complexity: Low Hanging Fruit
• Assignee: Unassigned
• Reporter: Michaël Figuière
• Created: 28/Feb/15 00:30
• Updated: 13/Jun/19 18:28

Description

AFAIK there's currently no way to monitor the amount of tombstones created on a Cassandra node. CASSANDRA-6057 has made it possible for users to figure out how many tombstones are scanned at read time, but in write mostly workloads, it may not be possible to realize if some inappropriate queries are generating too many tombstones.

Therefore the following additional metrics should be added:

• writtenCells: amount of cells that have been written
• writtenTombstoneCells: amount of tombstone cells that have been written

Alternatively these could be exposed as a single gauge such as writtenTombstoneCellsRatio.