The Agent start-up instantiates a global logger. The Agent uses this logger to record significant events related to general Agent processes and service execution. You have access to this logger in custom HydraExpress server-side code. You can also create your own loggers if you want to log information to locations other than the default log output file.

You can log information from any custom service that you write. In many cases, logging is simply added to an existing service to log specific data, but you might also create a separate service just to log some information.