Performance degradation on tunneled connection

I’ve experienced performance degradation when upgraded from 2.2.2 to 2.3.7. see measurements in attachment which was made by Spark application calling spark.catalog.listTables(). newer WD is 3 times slower impacting the ssh-tunneled connections (see highlighted rows) the most.

how much can it be eliminated?

[rambrus]

@bAndie91 , @patduin: I did some investigation and found this:

Test Case 1 - listTables on non-tunneled connection

wd version	run-1	run-2
2.3.0	20 s	19 s
2.3.1	20 s	23 s
2.3.2	25 s	24 s
2.3.3	36 s	32 s
2.3.4	28 s	25 s
2.3.5	44 s	56 s
2.3.6	48 s	46 s

Test Case 2 - listTables on tunneled connection

wd version	run-1	run-2
2.3.0	5 m 37 s	4 m 52 s
2.3.1	4 m 59 s	5 m 04 s
2.3.2	5 m 15 s	5 m 11 s
2.3.3	7 m 27 s	7 m 12 s
2.3.4	5 m 14 s	5 m 15 s
2.3.5	13 m 02 s	13 m 27 s
2.3.6	12 m 33 s	13 m 07 s

Summary I had 2 runs for both test cases, the test durations are pretty much consistent between runs and we can observe ~150% performance degradation between 2.3.4 and 2.3.5 releases.

IMPORTANT: The performance degradation does not seem to be specific to tunneled connection, the same trend can be observed in both cases.

[rambrus]

@bAndie91 , @patduin

Re-run the test cases on the version built from issue-115 branch and added the results to the charts.

Test Case 1 - listTables on non-tunneled connection

Test Case 2 - listTables on tunneled connection

I can confirm that the fix resolves the performance degradation issue.

Also the RetryingMetaStoreClient:184 - MetaStoreClient lost connection. Attempting to reconnect. warning disappeared from the logs.