Node data disk full

OceanBase Database rarely experiences full data disk space, but when it happens, it can lead to issues such as inability to perform minor compaction, major compaction, and memory release, ultimately causing the cluster to be unable to write.

Emergency handling procedure

Address the issue of full data disk space based on the following scenarios:

• For OBServer nodes with multiple tenants, add more nodes and migrate some resource units to the added nodes.

  1. Add more nodes

     This can be done through OCP or command line. For detailed instructions, see Add an OBServer node.

  2. Migrate resource units

     Use OCP to manually migrate some resource units to the added nodes. For detailed instructions, see View unit distribution. Note that resource units can only be migrated within the same zone.

• For other scenarios, use the following methods:

  • Increase the maximum data disk usage of the OceanBase cluster.

    ALTER system SET datafile_disk_percentage = 98;
    

    The default value of the datafile_disk_percentage parameter is 90. Increasing it during emergencies can temporarily release some space.

  • Delete some redundant data, tables, and indexes, and empty the recycle bin. Please carefully confirm before executing the data cleanup, as the data in the recycle bin cannot be recovered once cleared.