logging

You learned how to handle errors in Error Handling. This page describes how to set up logging and log query execution and errors.

Logging is an important part of understanding application behavior and diagnosing problems. ldbc provides a customizable logging system that can be integrated with any logging library.

ldbc can export execution and error logs of database connections in any format using any logging library.

By default, a logger using Cats Effect's Console is provided, which can be used during development.

To customize logging using an arbitrary logging library, use ldbc.sql.logging.LogHandler.

The following is the standard implementation of logging. ldbc generates the following three types of events on database connection.

def console[F[_]: Console: Sync]: LogHandler[F] =
  case LogEvent.Success(sql, args) =>
    Console[F].println(
      s"""Successful Statement Execution:
         |  $sql
         |
         | arguments = [${ args.mkString(",") }]
         |""".stripMargin
    )
  case LogEvent.ProcessingFailure(sql, args, failure) =>
    Console[F].errorln(
      s"""Failed ResultSet Processing:
         |  $sql
         |
         | arguments = [${ args.mkString(",") }]
         |""".stripMargin
    ) >> Console[F].printStackTrace(failure)
  case LogEvent.ExecFailure(sql, args, failure) =>
    Console[F].errorln(
      s"""Failed Statement Execution:
         |  $sql
         |
         | arguments = [${ args.mkString(",") }]
         |""".stripMargin
    ) >> Console[F].printStackTrace(failure)

The created LogHandler can be passed as an argument to setLogHandler when creating a Provider to use any log output method.

import ldbc.connector.*
val provider =
  ConnectionProvider
    .default[IO]("127.0.0.1", 3306, "ldbc", "password", "ldbc")
    .setSSL(SSL.Trusted)
    .setLogHandler(console[IO])

Next Steps

Now you know how to set up logging in ldbc. Setting up proper logging will make it easier to monitor application behavior and diagnose problems.

Next, go to Custom Data Types to learn how to use your own data types in ldbc.