Configuring RocksDB state backend
You can use RocksDB as a state backend when your Flink streaming application requires a larger state that doesn’t fit easily in memory. The RocksDB state backend uses a combination of fast in-memory cache and optimized disk based lookups to manage state.
You can configure the state backend for your streaming application by using the state.backend parameter directly or in Cloudera Manager under the Configuration tab:
You can adjust how much memory RocksDB should use as a cache to increase lookup performance by setting the memory managed fraction of the TaskManagers in Cloudera Manager under the Configuration tab:
The default fraction value is 0.4, but with larger cache requirements you need to increase this value together with the total memory size.