Reduce cardinality of default Tomcat JDBC pool names

[YaoYingLong]

Description

Tomcat JDBC generates default pool names in this format:

Tomcat Connection Pool[<counter>-<PoolProperties identity hash>]

The identity hash makes the pool.name / db.client.connection.pool.name
metric attribute unstable across JVM instances and can create unnecessary
time-series cardinality.

This change:

• detects Tomcat-generated default pool names and unnamed pools;
• derives a stable pool name from the JDBC URL and connection properties as
  server.address[:server.port][/db.namespace];
• preserves explicitly configured pool names;
• falls back to tomcat-jdbc when no server address or database namespace can
  be derived;
• intentionally allows pools targeting the same database to share a metric
  attribute value, which is aggregated by asynchronous metric observation.

Only automatically generated or unnamed pool names are affected. Explicit pool
names continue to be reported unchanged.

Compatibility

The implementation uses DataSourceProxy#getPoolProperties() together with
PoolConfiguration#getUrl() and PoolConfiguration#getDbProperties(). These
APIs are available across the supported Tomcat JDBC versions.

[Copilot]

Pull request overview

Reduces metric cardinality by normalizing Tomcat-generated JDBC pool names while retaining configured names.

Changes:

• Maps generated names to process-local jdbc-<id> values.
• Tests multiple pools, configured names, and repeated lifecycle calls.

Reviewed changes

Copilot reviewed 2 out of 2 changed files in this pull request and generated 1 comment.

File	Description
TomcatConnectionPoolMetrics.java	Detects and normalizes generated pool names.
TomcatJdbcInstrumentationTest.java	Verifies naming and lifecycle behavior.

[opentelemetry-pr-dashboard]

Pull request dashboard status

Status last refreshed: 2026-07-22 01:49:48 UTC.

• Waiting on: Reviewers
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