Truong Duc Kien created FLINK-9070: -------------------------------------- Summary: Improve performance of RocksDBMapState.clear() Key: FLINK-9070 URL: https://issues.apache.org/jira/browse/FLINK-9070 Project: Flink Issue Type: Improvement Components: State Backends, Checkpointing Affects Versions: 1.6.0 Reporter: Truong Duc Kien
Currently, RocksDBMapState.clear() is implemented by iterating over all the keys and drop them one by one. This iteration can be quite slow with: * Large maps * High-churn maps with a lot of tombstones There are a few methods to speed-up deletion for a range of keys, each with their own caveats: * DeleteRange: still experimental, likely buggy * DeleteFilesInRange + CompactRange: only good for large ranges Flink can also keep a list of inserted keys in-memory, then directly delete them without having to iterate over the Rocksdb database again. Reference: * [RocksDB article about range deletion|https://github.com/facebook/rocksdb/wiki/Delete-A-Range-Of-Keys] * [Bug in DeleteRange|https://pingcap.com/blog/2017-09-08-rocksdbbug] -- This message was sent by Atlassian JIRA (v7.6.3#76005)