Configuring compaction settings for SSTables (deprecated)
This content applies only to On-premises and Client-managed cloud environments
Maintain the good health of the Cassandra cluster by tuning compaction throughput for write-intensive workloads.
Cassandra might write multiple versions of a row to different SSTables. Often, each
version has a unique set of columns that Cassandra stores with a different time stamp.
As a result, the size of the SSTables grows, and the data distribution might require
accessing an increasing number of SSTables to retrieve a complete row of data. Cassandra
periodically merges SSTables and discards old data through compaction, to keep the
Starting in Pega Platform version 8.6, the use of an internal Cassandra database is deprecated. On-premises and client-managed cloud systems that have been updated from earlier versions of Pega Platform can continue to use Cassandra in embedded mode. However, to ensure future compatibility, do not create any new environments using embedded Cassandra.
- For every Decision Data Store (DDS) node, add the following dynamic system
- In the Pega-Engine ruleset, set the same number of concurrent compactors by adding the prconfig/dnode/yaml/concurrent_compactors/default property with the value that represents the number of CPU cores.
- In the Pega-Engine ruleset, configure the
compaction throughput by adding the
property with the following value: 256.
For more information, see Configuring dynamic system settings.
Determining the most appropriate compaction throughput setting is an iterative process. You can use the nodetool to adjust the compaction throughput for one node at a time, without requiring a node restart. In that case, any changes are reverted after the restart. For more information about the nodetool commands for compaction throughput, see the Apache Cassandra documentation.
- Restart all DDS nodes.For more information, see Managing decision management nodes.
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