Using NuoDB Logging

Logging in NuoDB is performed as follows.

Logging Message Flows
Figure 1. Logging Message Flows

  • Database engines (TEs and SMs) send their logging over the network to the Admin Process (AP) responsible for them.

  • The Admin Process (nuoadmin) writes writes all logging (its own plus logging it receives from the engines) to a single file: nuoadmin.log.

  • How the AP generates its own logs is defined by properties in nuoadmin.conf - see NuoDB Admin Logging.

  • How the engines generate logs is defined by options passed to the engines at startup - see default logging

  • The logging level of the AP does not affect, filter or reduce the engine logging in any way.

  • Engine logs (only) can optionally be sent to the local syslog (Unix only) and/or a remote syslog, in addition to nuoadmin.log.

NuoDB offers several levels of logging:

  • Default logging is defined at process start time

  • Additional, on-demand, or dynamic, logging can be requested at any time while the database is running.

  • The amount of logging detail is controlled by the logging level; NuoDB supports 4 logging levels: error, warn, info and debug.

  • What is logged is defined by logging categories.

Before configuring logging, decide:

  • Whether to log to a log file, to syslog, and/or to a remote syslog (typically for integration with third-party log managers)

  • How much information to log (the levels)

  • What to log (the categories)