[ https://issues.apache.org/jira/browse/KAFKA-10494?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel ]
Andy Coates reassigned KAFKA-10494: ----------------------------------- Assignee: Andy Coates > Streams: enableSendingOldValues should not call parent if node is itself > materialized > ------------------------------------------------------------------------------------- > > Key: KAFKA-10494 > URL: https://issues.apache.org/jira/browse/KAFKA-10494 > Project: Kafka > Issue Type: Improvement > Components: streams > Reporter: Andy Coates > Assignee: Andy Coates > Priority: Major > > Calling `enableSendingOldValues` on many nodes, e.g. `KTableFilter`, is > unnecessarily calling `enableSendingOldValues` on the parent, even when the > processor itself is materialized. This can force the parent table to be > materialized unnecessarily. > For example: > {code:java} > StreamsBuilder builder = new StreamsBuilder();builder > .table("t1", Consumed.of(...)) > .filter(predicate, Materialized.as("t2")) > .<downStreamOps> > {code} > If `downStreamOps` result in a call to `enableSendingOldValues` on the table > returned by the `filter` call, i.e. `t2`, then it will result in `t1` being > materialized unnecessarily. > This ticket was raised off the back of [comments in a > PR|#discussion_r490152263]] while working on KAFKA-10077. > A good test that highlights this would be to add this to `KTableFilterTest`: > {code:java} > @Test > public void > shouldEnableSendOldValuesIfSourceTableNotMaterializedButFinalTableIsEvenIfNotForcedToMaterialize() > { > final StreamsBuilder builder = new StreamsBuilder(); > final String topic1 = "topic1"; > final KTableImpl<String, Integer, Integer> table1 = > (KTableImpl<String, Integer, Integer>) builder.table(topic1, consumed); > final KTableImpl<String, Integer, Integer> table2 = > (KTableImpl<String, Integer, Integer>) table1.filter(predicate, > Materialized.as("store2")); > table2.enableSendingOldValues(false); > doTestSendingOldValue(builder, table1, table2, topic1); > } > {code} > Though this problem is not restricted to the filter call. Other processor > suppliers suffer from the same issue. > In addition, once [https://github.com/apache/kafka/pull/9156] is merged, if > you call {{enableSendingOldValues}} without forcing materialization on a > table that is itself materialized, but who's upstream is not. In such a > situation, the table will _not_ enable sending old values, but should. > -- This message was sent by Atlassian Jira (v8.3.4#803005)