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MySQL semi-sync cluster logs

For a MySQL semi-sync Managed Database cluster, MySQL service events and slow queries are logged.

Logs can be retrieved via the Logs service. For more information on how the service works and its pricing, see the General information about the Logs service guide. You can check service availability in regions in the Logs availability matrix.

To collect cluster logs in the Logs service, enable logging. Logs can only be retrieved from the service via API. If you no longer need to collect logs, you can disable logging.

Slow query logs can be viewed in the Managed Databases section of the control panel. You do not need to enable logging in the Logs service for this.

Logs are stored for 30 days.

Learn more about logs in the MySQL Server Logs section of the MySQL documentation.

Manage logs in the Logs service

Enable logging

You can enable logging via the API or in the Control Panel:

Enable logging in an existing cluster

Logging uses a portion of the cluster's computing resources. To control the amount of consumed resources, monitor the cluster node metrics. For more information on how to view metrics, see the article Monitoring of the cluster, nodes and databases MySQL semi-sync.

  1. In the Control Panel, in the top menu, click Products and select Managed Databases.
  2. Open the Active tab.
  3. Open the cluster page → Settings tab.
  4. In the Logging block, in the Log service field, click Connect.
  5. Select a log group or create a new group.
  6. If you selected a new group, enter its name.
  7. Click Save.

Get logs

Use the Get logs guide in the Logs section.

Event streams mysql.log-<instance_id> and slow.log-<instance_id> will be created, where <instance_id> is the identifier of the MySQL semi-sync cluster node.

Logged events are defined by the log_error_verbosity = 2 parameter, so events of ERROR and WARNING levels are logged. See the description of log fields for a MySQL semi-sync cluster.

Disable logging

  1. In the Dashboard, on the top menu, click Products and select Managed Databases.
  2. Open the Active tab.
  3. Open the cluster page → Settings tab.
  4. In the Logging block, in the Log service field, click .
  5. Uncheck the Collect cluster technical logs to log service checkbox.
  6. Click Save.

View slow query logs in the control panel

By default, queries to databases that take longer than two seconds are considered slow. To change this value, change the long_query_time database setting.

In the logs, you can see what a slow query looked like, its duration, and when and by which user it was executed. Queries can be filtered by time range, cluster nodes, and databases.

  1. In the control panel, in the top menu, click Products and select Managed Databases.
  2. Open the Active tab.
  3. Open the cluster page → Logs tab.
  4. Enter the time range for which you want to display logs. Logs are stored for 30 days.
  5. Select the cluster nodes and databases for which you want to view logs.
  6. The list displays the first 200 queries. To view all queries for the specified time range, click Download logs. See the description of log fields for a MySQL semi-sync cluster.

Log fields

_HOSTNAMECluster node name in the format dbaas-<instance_id>, where <instance_id> is the identifier of the MySQL semi-sync cluster node
SYSLOG_IDENTIFIERLog source name
SYSLOG_TIMESTAMPEvent time in the log
MESSAGEDescription of the event submitted by the log source