[
https://issues.apache.org/jira/browse/KAFKA-4212?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=16886605#comment-16886605
]
Steve Cosenza edited comment on KAFKA-4212 at 7/17/19 1:30 AM:
---
For reference, Apache Samza supports RocksDB with TTL support when strict
correctness isn't required (Search for "Using RocksDB TTL" here
[https://cwiki.apache.org/confluence/display/SAMZA/How+to+configure+your+RocksDB+state+store])
was (Author: scosenza):
For reference, Apache Samza supports RocksDB with TTL support when strict
correctness isn't required (see
[https://cwiki.apache.org/confluence/display/SAMZA/How+to+configure+your+RocksDB+state+store])
> Add a key-value store that is a TTL persistent cache
>
>
> Key: KAFKA-4212
> URL: https://issues.apache.org/jira/browse/KAFKA-4212
> Project: Kafka
> Issue Type: Improvement
> Components: streams
>Affects Versions: 0.10.0.1
>Reporter: Elias Levy
>Priority: Major
> Labels: api
>
> Some jobs needs to maintain as state a large set of key-values for some
> period of time. I.e. they need to maintain a TTL cache of values potentially
> larger than memory.
> Currently Kafka Streams provides non-windowed and windowed key-value stores.
> Neither is an exact fit to this use case.
> The {{RocksDBStore}}, a {{KeyValueStore}}, stores one value per key as
> required, but does not support expiration. The TTL option of RocksDB is
> explicitly not used.
> The {{RocksDBWindowsStore}}, a {{WindowsStore}}, can expire items via segment
> dropping, but it stores multiple items per key, based on their timestamp.
> But this store can be repurposed as a cache by fetching the items in reverse
> chronological order and returning the first item found.
> KAFKA-2594 introduced a fixed-capacity in-memory LRU caching store, but here
> we desire a variable-capacity memory-overflowing TTL caching store.
> Although {{RocksDBWindowsStore}} can be repurposed as a cache, it would be
> useful to have an official and proper TTL cache API and implementation.
--
This message was sent by Atlassian JIRA
(v7.6.14#76016)
