I want kafka to only store the latest value of a given key in a topic. This seems so be possible, as shown here.
However, the only think I archived so far, are that ALL Key/Value pairs get deleted or nothing at all. I replace a given Key/Value pair with the code example of the link above in a java program. This leads to have the same Key TWICE in a topic, once with a Value, once with NULL.
Heres my server.properties
listeners=kafka0://SERVERIP:9092
num.network.threads=3
num.io.threads=8
socket.send.buffer.bytes=102400
socket.receive.buffer.bytes=102400
socket.request.max.bytes=104857600
log.dirs=/tmp/kafka-logs
num.partitions=5
num.recovery.threads.per.data.dir=1
offsets.topic.replication.factor=1
transaction.state.log.replication.factor=1
transaction.state.log.min.isr=1
############################# Log Retention Policy #############################
# The minimum age of a log file to be eligible for deletion due to age
#168
log.retention.minutes=1
# A size-based retention policy for logs. Segments are pruned from the log unless the remaining
# segments drop below log.retention.bytes. Functions independently of log.retention.hours.
#log.retention.bytes=1073741824
log.retention.bytes=200000
# The maximum size of a log segment file. When this size is reached a new log segment will be created.
#log.segment.bytes=1073741824
log.segment.bytes=200000
# The interval at which log segments are checked to see if they can be deleted according
# to the retention policies
log.retention.check.interval.ms=2000
log.cleaner.enable=true
#Ensure compaction runs continuously
log.cleaner.min.cleanable.ratio = 0.00001
#Set a limit on compaction so there is bandwidth for regular activities
log.cleaner.io.max.bytes.per.second=1000000
#
log.roll.ms=60000
############################# Group Coordinator Settings #############################
delete.topic.enable = true
auto.create.topics.enable = false
And here are the settings of a topic: Topicsettings
