Enviroments:
./openflowplugin/distribution/karaf/target/assembly/bin/karaf debug -Xmx2G -XX:MaxPermSize=512m
mn --topo tree,3 --controller 'remote,ip=127.0.0.1,port=6653' --switch ovsk,protocols=OpenFlow13
feature:install odl-openflowplugin-flow-services odl-restconf

Reproduce activity:
add/remove 3 times 5K flows and forget close karaf (cca 5 min without any flows)

Uncaught error from thread [opendaylight-cluster-data-akka.persistence.dispatchers.default-plugin-dispatcher-58] shutting down JVM since 'akka.jvm-exit-on-fatal-error' is enabled for ActorSystem[opendaylight-cluster-data]
java.lang.OutOfMemoryError: Java heap space
at java.util.Arrays.copyOf(Arrays.java:2271)
at java.io.ByteArrayOutputStream.grow(ByteArrayOutputStream.java:113)
at java.io.ByteArrayOutputStream.ensureCapacity(ByteArrayOutputStream.java:93)
at java.io.ByteArrayOutputStream.write(ByteArrayOutputStream.java:140)
at java.io.ObjectOutputStream$BlockDataOutputStream.drain(ObjectOutputStream.java:1876)
at java.io.ObjectOutputStream$BlockDataOutputStream.setBlockDataMode(ObjectOutputStream.java:1785)
at java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1188)
at java.io.ObjectOutputStream.writeObject(ObjectOutputStream.java:347)
at akka.serialization.JavaSerializer$$anonfun$toBinary$1.apply$mcV$sp(Serializer.scala:129)
at akka.serialization.JavaSerializer$$anonfun$toBinary$1.apply(Serializer.scala:129)
at akka.serialization.JavaSerializer$$anonfun$toBinary$1.apply(Serializer.scala:129)
at scala.util.DynamicVariable.withValue(DynamicVariable.scala:57)
at akka.serialization.JavaSerializer.toBinary(Serializer.scala:129)
at akka.persistence.serialization.MessageSerializer.akka$persistence$serialization$MessageSerializer$$payloadBuilder$1(MessageSerializer.scala:151)
at akka.persistence.serialization.MessageSerializer$$anonfun$akka$persistence$serialization$MessageSerializer$$persistentPayloadBuilder$1.apply(MessageSerializer.scala:158)
at akka.persistence.serialization.MessageSerializer$$anonfun$akka$persistence$serialization$MessageSerializer$$persistentPayloadBuilder$1.apply(MessageSerializer.scala:158)
at scala.util.DynamicVariable.withValue(DynamicVariable.scala:57)
at akka.persistence.serialization.MessageSerializer.akka$persistence$serialization$MessageSerializer$$persistentPayloadBuilder(MessageSerializer.scala:158)
at akka.persistence.serialization.MessageSerializer.akka$persistence$serialization$MessageSerializer$$persistentMessageBuilder(MessageSerializer.scala:136)
at akka.persistence.serialization.MessageSerializer.toBinary(MessageSerializer.scala:53)
at akka.serialization.Serialization$$anonfun$serialize$1.apply(Serialization.scala:90)
at akka.serialization.Serialization$$anonfun$serialize$1.apply(Serialization.scala:90)
at scala.util.Try$.apply(Try.scala:161)
at akka.serialization.Serialization.serialize(Serialization.scala:90)
at akka.persistence.journal.leveldb.LeveldbStore$class.persistentToBytes(LeveldbStore.scala:96)
at akka.persistence.journal.leveldb.LeveldbJournal.persistentToBytes(LeveldbJournal.scala:20)
at akka.persistence.journal.leveldb.LeveldbStore$class.akka$persistence$journal$leveldb$LeveldbStore$$addToMessageBatch(LeveldbStore.scala:102)
at akka.persistence.journal.leveldb.LeveldbStore$$anonfun$writeMessages$1$$anonfun$apply$1.apply(LeveldbStore.scala:44)
at akka.persistence.journal.leveldb.LeveldbStore$$anonfun$writeMessages$1$$anonfun$apply$1.apply(LeveldbStore.scala:44)
at scala.collection.Iterator$class.foreach(Iterator.scala:727)
at scala.collection.AbstractIterator.foreach(Iterator.scala:1157)
at scala.collection.IterableLike$class.foreach(IterableLike.scala:72)