HADR Calculator
When you enable HADR on a database, the logs on the primary database are replicated to one or more standby databases in real time. This replication can slow down the log writing process on the primary database. The HADR Calculator will help you assess the impact caused by the slow down.
The HADR Calculator uses the output from the Db2 Log Scanner to estimate HADR performance in various synchronization modes. You can use it in conjunction with the HADR Simulator to conduct any necessary performance tuning for HADR.
The following factors impact log writing on the primary database:
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Log device speed on primary and standby databases
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Network speed between primary and standby databases
The HADR calculator computes the logging rate of the peer state for SYNC, NEARSYNC, and ASYNC modes, where log writing can be slowed down by log shipping.
For the SUPERASYNC mode, the HADR calculator computes the logging rate of the remote catchup state, as HADR does not enter the peer state in this mode.