Phase Count and Phase Ratio Tuning Redistribution and Replication
You can control the pace and throttling of redistribution and replication be by using the space definition settings.
- Phase Count - The Java setPhaseCount method sets the number of phases that are used during redistribution and replication.
- A phase count of 1 provides the fastest redistribution/replication time, but at the expense of incurring the most impact on ongoing space operations (no client requests are serviced until the redistribution/replication is completed).
- The default value (-1) specifies that the total number of records that need to be redistributed or replicated is divided by 100,000 to compute the number of phases.
- Phase Ratio - The Java setPhaseCount method specifies a percentage of the time spent doing redistribution/replication versus the time spent servicing client requests.
By using the values that you specify for the Phase Count and the Phase Ratio, ActiveSpaces computes the amount of time to wait before starting the next phase, as follows:
Amount of time to wait before starting next phase = Amount of time spent during a phase * Phase ratio percentage
The default value is 100 (%), which indicates that if, on average, a redistribution/replication phase takes x ms to complete, then redistribution/replication is paused for 100% of x ms until the next phase starts.