Documentation

JDBC

The kamon-jdbc module brings bytecode instrumentation to trace jdbc-compatible database requests

The kamon-jdbc module requires you to start your application using the AspectJ Weaver Agent. Kamon will warn you at startup if you failed to do so.

The bytecode instrumentation provided by the kamon-jdbc module hooks into the JDBC API to automatically start and finish segments for requests that are issued within a trace. This translates into you having metrics about how the requests you are doing are behaving.

Metrics

The following metrics will be recorded:

  • reads: a histogram that tracks the reads requests latency (SELECT statement).
  • writes: a histogram that tracks the writes requests latency (INSERT, UPDATE, and DELETE statements).
  • slows: a simple counter with the number of measured slow requests.
  • errors: a simple counter with the number of failures.

Naming Segments

By default, the name generator bundled with the kamon-jdbc module will use the statement name as the name to the automatically generated segment (i.e SELECT, INSERT, etc). Currently, the only way to override that name would be to provide your own implementation of kamon.jdbc.JdbcNameGenerator which is used to assign the segment name

Slow Requests

Requests that take longer to execute than the configured kamon.jdbc.slow-query-threshold can be processed by user-defined kamon.jdbc.DefaultSlowQueryProcessor. The default processor logs a warning message

Error Processor

Requests that error can be processed by user-defined kamon.jdbc.SqlErrorProcessor. The default processor logs an error message

Configuration

kamon {
  jdbc {
    slow-query-threshold = 2 seconds

    # Fully qualified name of the implementation of kamon.jdbc.SlowQueryProcessor.
    slow-query-processor = kamon.jdbc.DefaultSlowQueryProcessor

    # Fully qualified name of the implementation of kamon.jdbc.SqlErrorProcessor.
    sql-error-processor = kamon.jdbc.DefaultSqlErrorProcessor

    # Fully qualified name of the implementation of kamon.jdbc.JdbcNameGenerator that will be used for assigning names to segments.
    name-generator = kamon.jdbc.DefaultJdbcNameGenerator
  }
}