archive_lag_target specifies the lag of log archiving in a tenant.
Note
This parameter was introduced in OceanBase Database V4.2.0.
Attribute |
Description |
|---|---|
| Type | Time |
| Default value | 120s |
| Value range | [0ms, 7200s] |
| Effective upon OBServer node restart | No |
Take note of the following considerations:
In the Physical Standby Database architecture based on log archiving, you can adjust the value of
archive_lag_targetbased on the synchronization latency required by the standby tenant. For example, you can set the value to half the synchronization latency required by the standby tenant.In other architectures, such as the network-based Physical Standby Database architecture, we recommend that you adjust the value of
archive_lag_targetbased on the write load of the tenant and the requirements for archiving timeliness. On the premise that the timeliness requirement is met, make sure that at least one log file of 64 MB is generated in a log stream within the period specified byarchive_lag_target.
Note
Archived files and log files are homogeneous in OceanBase Database. A log file can be uploaded and archived as a Normal type archive file.