Details
When a node starts, shuts down, or processes acockroach command, it produces a stream of messages about the command’s activities. Each message is composed of:
- A payload that contains events either structured in JSON or conveyed in an arbitrary string. For details on structured event types and their fields, see Notable Event Types.
- An envelope that contains event metadata (e.g., severity, date, timestamp, channel). Depending on the log format you specify when configuring logs, the envelope can be formatted either in JSON or as a flat prefix to the message.
Logging channels
Log channels cannot be completely disabled. You can configure how log messages are routed to different sinks and adjust verbosity levels, but you cannot turn off a log channel entirely. For example, a channel that is not explicitly configured for a file group is enabled in the
default file group.
Logging channels are analogous to logging facilities in Syslog or logging services in Datadog. For more details on the contents of each logging channel, see the Logging reference.
log.channel_compatibility_mode.enabled
New in v25.4: The log.channel_compatibility_mode.enabled cluster setting controls logging channel behavior. When set to:
true(default): Logs are sent to the standard logging channels. This maintains the behavior in v25.3 and earlier supported versions. Specifically, the system sends:- Changefeed telemetry events to the
TELEMETRYchannel. - SQL Slow Query Log and SQL Slow Query Log (Internal) events to the
SQL_PERFandSQL_INTERNAL_PERFchannels, respectively. sampled_queryandsampled_transactionevents to theTELEMETRYchannel.
- Changefeed telemetry events to the
false: Logs are sent to updated logging channels. Specifically, the system sends:- Changefeed telemetry events to the
CHANGEFEEDchannel. - SQL Slow Query Log and SQL Slow Query Log (Internal) events to the
SQL_EXECchannel. sampled_queryandsampled_transactionevents to theSQL_EXECchannel.
- Changefeed telemetry events to the
In a future release,
log.channel_compatibility_mode.enabled is expected to default to false. To prepare for that change and assess potential downstream impacts on your logging setup and pipelines, set the log.channel_compatibility_mode.enabled cluster setting to false in a non-production environment.Logging destinations
When using the default logging configuration, the events collected on each logging channel are split into log files as follows:
Logging destinations and many other parameters are configurable via YAML. For details, see Configure Logs.

