[email protected] has posted comments on this change. ( http://gerrit.cloudera.org:8080/24324 )
Change subject: IMPALA-14936: [DOCS] Hierarchical metastore event processing ...................................................................... Patch Set 1: (5 comments) http://gerrit.cloudera.org:8080/#/c/24324/1/docs/topics/impala_metadata.xml File docs/topics/impala_metadata.xml: http://gerrit.cloudera.org:8080/#/c/24324/1/docs/topics/impala_metadata.xml@313 PS1, Line 313: This feature is controlled by the : <codeph>‑‑hms_event_polling_interval_s</codeph> flag. Start the : <codeph>catalogd</codeph> with the <codeph>‑‑hms_event_polling_interval_s</codeph> : flag set to a positive double value to enable the feature and set the polling frequency in : seconds. We recommend the value between 1.0 to 5.0 seconds. This is the recommendation when hierarchical event processing is not enabled. We support lower than 1sec with HEP. I think, we need to update this. And we can remove hms_event_polling_interval_s from Catalogd configuration properties section added below. http://gerrit.cloudera.org:8080/#/c/24324/1/docs/topics/impala_metadata.xml@707 PS1, Line 707: <concept id="hierarchical_event_processing"> Suggest to keep hierarchical_event_processing after disable_event_based_metadata_sync like below: auto_poll_hms_notification ??? configure_event_based_metadata_sync ??? disable_event_based_metadata_sync ??? hierarchical_event_processing http://gerrit.cloudera.org:8080/#/c/24324/1/docs/topics/impala_metadata.xml@736 PS1, Line 736: <li>>Database event executor – Manages table event nit: There is an additional > before Database http://gerrit.cloudera.org:8080/#/c/24324/1/docs/topics/impala_metadata.xml@767 PS1, Line 767: </ul></p> I think, we can add about backpressure mechanism- When the number of outstanding events to be processed on db event executors and table event executors exceed the threshold configured by --max_outstanding_events_on_executors, the processor temporarily stops fetching new events from HMS as a backpressure mechanism. http://gerrit.cloudera.org:8080/#/c/24324/1/docs/topics/impala_metadata.xml@789 PS1, Line 789: <entry>Enables hierarchical event processing on Catalogd. This is disabled by Enabled by default. May be it is good to mention how to disable it if user do not wish to enable it by default? Do we have show default values for other params too? -- To view, visit http://gerrit.cloudera.org:8080/24324 To unsubscribe, visit http://gerrit.cloudera.org:8080/settings Gerrit-Project: Impala-ASF Gerrit-Branch: master Gerrit-MessageType: comment Gerrit-Change-Id: Ib57bc4df70edf513a826a715d5bf842e9a580a34 Gerrit-Change-Number: 24324 Gerrit-PatchSet: 1 Gerrit-Owner: Sanjana Malhotra <[email protected]> Gerrit-Reviewer: Anonymous Coward <[email protected]> Gerrit-Reviewer: Impala Public Jenkins <[email protected]> Gerrit-Reviewer: Quanlong Huang <[email protected]> Gerrit-Reviewer: Sanjana Malhotra <[email protected]> Gerrit-Comment-Date: Mon, 29 Jun 2026 09:54:59 +0000 Gerrit-HasComments: Yes
