Hi Kiran You can use the RocksDBConfigSetter and pass options.setMaxOpenFiles(100);
to all RocksDBs for the Streams application which limits how many are kept open at the same time. best regards Patrik On Wed, 26 Jun 2019 at 16:14, emailtokir...@gmail.com < emailtokir...@gmail.com> wrote: > Hi, > > We are using Kafka streams DSL APIs for doing some counter aggregations > (running on OpenJDK 11.0.2). Our topology has some 400 sub topologies & we > are using 8 partitions in source topic. When we start pumping more load, we > start getting RockDBException stating "too many open files". > > Here are the stack trace samples: > > ------------------------------------------------------------------------------------------ > Caused by: org.rocksdb.RocksDBException: while open a file for lock: > PPPPPPPPPPP.1512000000/LOCK: Too many open files > at org.rocksdb.RocksDB.open(Native Method) > at org.rocksdb.RocksDB.open(RocksDB.java:235) > at > org.apache.kafka.streams.state.internals.RocksDBStore.openDB(RocksDBStore.java:156) > ... 24 common frames omitted > > > Caused by: org.apache.kafka.streams.errors.ProcessorStateException: Error > while executing flush from store XXXXXXXXXXX.1512000000 > at > org.apache.kafka.streams.state.internals.RocksDBStore.flushInternal(RocksDBStore.java:397) > at > org.apache.kafka.streams.state.internals.RocksDBStore.flush(RocksDBStore.java:388) > at > org.apache.kafka.streams.state.internals.Segments.flush(Segments.java:163) > at > org.apache.kafka.streams.state.internals.RocksDBSegmentedBytesStore.flush(RocksDBSegmentedBytesStore.java:178) > at > org.apache.kafka.streams.state.internals.WrappedStateStore$AbstractStateStore.flush(WrappedStateStore.java:85) > at > org.apache.kafka.streams.state.internals.WrappedStateStore$AbstractStateStore.flush(WrappedStateStore.java:85) > at > org.apache.kafka.streams.state.internals.CachingWindowStore.flush(CachingWindowStore.java:130) > at > org.apache.kafka.streams.state.internals.MeteredWindowStore.flush(MeteredWindowStore.java:177) > at > org.apache.kafka.streams.processor.internals.ProcessorStateManager.flush(ProcessorStateManager.java:217) > ... 10 more > Caused by: org.rocksdb.RocksDBException: While open a file for appending: > YYYYYYYYYYYYY.1512000000/000007.dbtmp: Too many open files > at org.rocksdb.RocksDB.flush(Native Method) > at org.rocksdb.RocksDB.flush(RocksDB.java:3401) > at org.rocksdb.RocksDB.flush(RocksDB.java:3361) > at > org.apache.kafka.streams.state.internals.RocksDBStore.flushInternal(RocksDBStore.java:395) > > ------------------------------------------------------------------------------------------ > > We tried increasing the open files limit at OS level to some decent > number.. but still no luck. Obviously we don't want to have boundless open > files.. > > We also tried to play with commit interval(kafka.commit.interval.ms) and > cache size (kafka.cache.max.bytes.buffering) .. but no luck there either. > > KAFKA-3904 talks about it.. but it was resolved long back.. > > Any other config tuning we have to do? > > Appreciate any help in this regard! > > Thanks, > Kiran > >