[jira] [Created] (KAFKA-5172) CachingSessionStore doesn't fetchPrevious correctly.

["Kyle Winkelman (JIRA)" <ji...@apache.org>]

Kyle Winkelman created KAFKA-5172:
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             Summary: CachingSessionStore doesn't fetchPrevious correctly.
                 Key: KAFKA-5172
                 URL: https://issues.apache.org/jira/browse/KAFKA-5172
             Project: Kafka
          Issue Type: Bug
          Components: streams
            Reporter: Kyle Winkelman


When using KStreamSessionWindowAggregate by calling KGroupedStream#aggregate() a CachingSessionStore is created.
This causes the following chain of method calls when a new record that requires removing others from the store appear:

KStreamSessionWindowAggregate
CachingSessionStore.remove(Windowed<K>)
CachingSessionStore.put(Windowed<K>, V)
ThreadCache.put(String, Bytes *containing Windowed<K> info*, LRUCacheEntry)
ThreadCache.maybeEvict(String)
NamedCache.evict()
NamedCache.flush(LRUNode *containing Bytes and LRUCacheEntry from ThreadCache#put*)
DirtyEntryFlushListener *defined in CachingSessionStore line 80* .apply(ThreadCache.DirtyEntry *containing Bytes and LRUCacheEntry from ThreadCache#put*)
CachingSessionStore.putAndMaybeForward(ThreadCache.DirtyEntry *containing Bytes and LRUCacheEntry from ThreadCache#put*, InternalProcessorContext)
CachingSessionStore.fetchPrevious(Bytes *containing Windowed<K> info*)
RocksDBSessionStore.fetch(Bytes *containing Windowed<K> info*)
RocksDBSessionStore.findSessions *on line 48* (Bytes *containing Windowed<K> info*, 0, Long.MAX_VALUE)
MeteredSegmentedByteStore.fetch(Bytes *containing Windowed<K> info*, 0, Long.MAX_VALUE)
ChangeLoggingSegmentedByteStore.fetch(Bytes *containing Windowed<K> info*, 0, Long.MAX_VALUE)
RocksDBSegmentedBytesStore.fetch(Bytes *containing Windowed<K> info*, 0, Long.MAX_VALUE)
SessionKeySchema.lower/upperRange(Bytes *containing Windowed<K> info*, Long)
****** in this method the already Windowed<K> gets Windowed again *****

The point of showing all this is to point out that the windowed gets windowed and because it passes the 0, Long.MAX_VALUE it searches for a strange key and searches all times for it. I think the fetchPrevious method of CachingSessionStore should be changed to call the byteStores.findSessions(Bytes.wrap(serdes.rawKey(key.key())), key.window().start(), key.window().end()). 



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