[CASSANDRA-19619] Enforce contract for internal metrics naming

• Type: Task
• Status: Resolved
• Priority: Normal
• Resolution: Fixed
• Fix Version/s: 5.0-rc1, 5.0, 5.1
• Component/s: Observability/Metrics
• Change Category: Semantic
• Complexity: Low Hanging Fruit
• Platform: All

Source Control Link

https://github.com/apache/cassandra/commit/ccdeb12419a70afb00e9aa3958fc05eb4617ee44

Test and Documentation Plan

n/a (shouldn't be any client-facing changes)

• Assignee: Maxim Muzafarov
• Reporter: Maxim Muzafarov

Authors

Maxim Muzafarov

Reviewers

Caleb Rackliffe, Michael Semb Wever

• Created: 03/May/24 21:52
• Updated: 20/May/24 11:24
• Resolved: 08/May/24 18:02

Description

Metrics have their internal representation which uniquely identifies a particular metric name. The name is formed as <metric group>.<metric type>.<metric name>.<metric scope>. For some metrics, the scope includes a metric name that is not necessary for uniqueness, this can be simplified.

For example,

// AS IS
org.apache.cassandra.metrics.StorageAttachedIndex.BalancedTreeIntersectionEarlyExits.my_keyspace.my_table.ColumnQueryMetrics.BalancedTreeIntersectionEarlyExits

// TO BE
org.apache.cassandra.metrics.StorageAttachedIndex.BalancedTreeIntersectionEarlyExits.my_keyspace.my_table.ColumnQueryMetrics

The metrics are filtered based on knowledge of how they are formatted, so having a metric scope without a built-in metric name also simplifies the way we filter metrics.

Issue Links

• links to: GitHub Pull Request #3291
• links to: GitHub Pull Request #3292