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 strategies:

1. For OBServer nodes that host multiple tenants, first consider balancing data by adding nodes and migrating units.

   • Add nodes

     You can add nodes through the OCP console or by using the command line. For detailed steps, see Add nodes.

   • Manually migrate units to the added nodes

     Use OCP to manually migrate units. You can double-click the unit specification to perform the migration. For detailed steps, see View unit distribution. Migration can only be performed within a single zone.

2. For scenarios where units cannot be migrated or data cannot be balanced through expansion, use the following emergency 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.