ilog_index_expire_time

Description

ilog_index_expire_time specifies the maximum time for which an OBServer node can provide Ilog files.

Attributes

Considerations

In OceanBase Database, file_id_cache caches the metadata information of all Ilog files and records the starting log number and timestamp of each partition in these Ilog files. By default, file_id_cache is cleared only when an Ilog file is deleted. Therefore, on servers with large disk space, file_id_cache may occupy a significant amount of memory. This issue is further exacerbated when partitions are frequently created and deleted.

You can adjust the value of ilog_index_expire_time to reduce the memory usage of file_id_cache. ilog_index_expire_time specifies the maximum time for which an OBServer node can provide Ilog files. Ilog files that exceed this time limit are not cached in file_id_cache, thus reducing memory usage.

When setting the value of this parameter:

• If you reduce the maximum time, the system will quickly clear the memory usage of file_id_cache. After the setting is applied, you can query the memory usage of ob_csr_file_id_cache to observe the changes.

• If you increase the maximum time, the system will cache Ilog files with a larger time span after the server restarts.

Examples

obclient> ALTER SYSTEM SET ilog_index_expire_time = '7d';