Quanlong Huang has posted comments on this change. ( 
http://gerrit.cloudera.org:8080/18926 )

Change subject: IMPALA-11540: Add logs for ALTER_TABLE events that trigger slow 
metadata reload
......................................................................


Patch Set 3:

(2 comments)

> Patch Set 3: Verified-1
>
> Build failed: https://jenkins.impala.io/job/gerrit-verify-dryrun/8542/

The failure is due to compilation error on Apache Hive 3.x:
https://jenkins.impala.io/job/all-build-options-ub1604/8722/console

http://gerrit.cloudera.org:8080/#/c/18926/3/fe/src/main/java/org/apache/impala/catalog/events/MetastoreEvents.java
File fe/src/main/java/org/apache/impala/catalog/events/MetastoreEvents.java:

http://gerrit.cloudera.org:8080/#/c/18926/3/fe/src/main/java/org/apache/impala/catalog/events/MetastoreEvents.java@1462
PS3, Line 1462:       long duration = System.currentTimeMillis() - start_ms;
> Hi quanlong, System.nanoTime() is more accurate than System.currentTimeMill
Done


http://gerrit.cloudera.org:8080/#/c/18926/3/fe/src/main/java/org/apache/impala/catalog/events/MetastoreEvents.java@1474
PS3, Line 1474:       if (tableBefore_.isSetColStats() || 
tableAfter_.isSetColStats()) {
The colStats field is added in HIVE-21078 which is not in Hive-3.1.2. This 
causes compilation error when building with Apache Hive 3.x.

In my experiments, the colStats is always null in the AlterTable events. It 
seems it's not set into the event, at least for the oldTable object:

https://github.com/apache/hive/blob/4e4e39c471094567dcdfd9840edbd99d7eafc230/standalone-metastore/metastore-server/src/main/java/org/apache/hadoop/hive/metastore/HMSHandler.java#L6117
https://github.infra.cloudera.com/CDH/hive/blob/64234e1217b105ac74216e7877a75a14b141ee6d/standalone-metastore/src/main/java/org/apache/hadoop/hive/metastore/HiveMetaStore.java#L3733

Hive also have codes logging the Table#toString() directly, e.g.
https://github.com/apache/hive/blob/4e4e39c471094567dcdfd9840edbd99d7eafc230/standalone-metastore/metastore-server/src/main/java/org/apache/hadoop/hive/metastore/MetastoreDefaultTransformer.java#L708
https://github.com/apache/hive/blob/4e4e39c471094567dcdfd9840edbd99d7eafc230/standalone-metastore/metastore-server/src/main/java/org/apache/hadoop/hive/metastore/MetastoreDefaultTransformer.java#L766

BTW, I think even if we log the stats, the complexity is the same as logging 
the column schema. There are no large binaries like incremental stats of Impala.

So I think it's ok to ignore these checks.



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Gerrit-Project: Impala-ASF
Gerrit-Branch: master
Gerrit-MessageType: comment
Gerrit-Change-Id: Ibf344e6b423f88c9635ca8d61d53385b88ba4dce
Gerrit-Change-Number: 18926
Gerrit-PatchSet: 3
Gerrit-Owner: Quanlong Huang <[email protected]>
Gerrit-Reviewer: Csaba Ringhofer <[email protected]>
Gerrit-Reviewer: Impala Public Jenkins <[email protected]>
Gerrit-Reviewer: Quanlong Huang <[email protected]>
Gerrit-Reviewer: Xiang Yang <[email protected]>
Gerrit-Reviewer: Yu-Wen Lai <[email protected]>
Gerrit-Comment-Date: Thu, 08 Sep 2022 07:42:06 +0000
Gerrit-HasComments: Yes

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