[jira] [Resolved] (KAFKA-8870) Prevent dirty reads of Streams state store from Interactive queries

["Boyang Chen (Jira)" <ji...@apache.org>]

     [ https://issues.apache.org/jira/browse/KAFKA-8870?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel ]

Boyang Chen resolved KAFKA-8870.
--------------------------------
    Resolution: Duplicate

> Prevent dirty reads of Streams state store from Interactive queries
> -------------------------------------------------------------------
>
>                 Key: KAFKA-8870
>                 URL: https://issues.apache.org/jira/browse/KAFKA-8870
>             Project: Kafka
>          Issue Type: Improvement
>          Components: streams
>            Reporter: Vinoth Chandar
>            Assignee: Boyang Chen
>            Priority: Major
>
> Today, Interactive Queries (IQ) against Streams state store could see uncommitted data, even with EOS processing guarantees (these are actually orthogonal, but clarifying since EOS may give the impression that everything is dandy). This is causes primarily because state updates in rocksdb are visible even before the kafka transaction is committed. Thus, if the instance fails, then the failed over instance will redo the uncommited old transaction and the following could be possible during recovery,.
> Value for key K can go from *V0 → V1 → V2* on active instance A, IQ reads V1, instance A fails and any failure/rebalancing will leave the standy instance B rewinding offsets and reprocessing, during which time IQ can again see V0 or V1 or any number of previous values for the same key.
> In this issue, we will plan work towards providing consistency for IQ, for a single row in a single state store. i.e once a query sees V1, it can only see either V1 or V2.
>  
>  
>  



--
This message was sent by Atlassian Jira
(v8.3.4#803005)