[SERVER-51451] Flaky mongos API version parameter tests Created: 09/Oct/20  Updated: 29/Oct/23  Resolved: 19/Oct/20

Status: Closed
Project: Core Server
Component/s: Replication
Affects Version/s: None
Fix Version/s: 5.0.0-rc0

Type: Bug Priority: Major - P3
Reporter: A. Jesse Jiryu Davis Assignee: A. Jesse Jiryu Davis
Resolution: Fixed Votes: 0
Labels: None
Remaining Estimate: Not Specified
Time Spent: Not Specified
Original Estimate: Not Specified

Issue Links:
Depends
Backwards Compatibility: Fully Compatible
Operating System: ALL
Sprint: Repl 2020-10-19, Repl 2020-11-02
Participants:
Linked BF Score: 23

 Description   

Two kinds of failures. First, an intermittent failure in api_params_nontransaction_sharded.js. On a 2-shard cluster with shard 0 and shard 1, the test does a "find" on mongos with $where: sleep(99999) and waits for the "find" command to appear in currentOp. Sometimes it times out without seeing the command in currentOp.

Second, an intermittent failure in api_params_nontransaction_unsharded.js and api_params_nontransaction_sharded.js. The test executes "find" with batchSize 1, and receives a cursorId in the "find" reply. The test executes the "killCursors" command with that cursorId, then searches for a "killCursors" command in the shard 0 primary's log, but doesn't find it.

I'm still diagnosing both failures.



 Comments   
Comment by Githook User [ 19/Oct/20 ]

Author:

{'name': 'A. Jesse Jiryu Davis', 'email': 'jesse@mongodb.com', 'username': 'ajdavis'}

Message: SERVER-51451 Fix mongos API version parameter tests, part 2
Branch: master
https://github.com/mongodb/mongo/commit/7728778a2138dddb951ab87e95c4337d8e653a86

Comment by A. Jesse Jiryu Davis [ 18/Oct/20 ]

Reopening, there's been a new failure of the first kind, a failure while waiting to see "find" in "currentOp". Since I've added more logging to the test I can see clearly the cause of the error: while the test is looking for one "find" command with a certain "comment" value in "currentOp", it sees two of them, one for each shard. It asserts that the number of "find" commands it sees is < 2, and fails.

In my previous fix I thought I'd avoided this possibility by adding a filter on the shard key in "find", but apparently mongos has targeted both shards anyway.

Comment by Githook User [ 14/Oct/20 ]

Author:

{'name': 'A. Jesse Jiryu Davis', 'email': 'jesse@mongodb.com', 'username': 'ajdavis'}

Message: SERVER-51451 Fix mongos API version parameter tests
Branch: master
https://github.com/mongodb/mongo/commit/f2380dd48d01bb62271b8c749b4d87984266160f

Generated at Thu Feb 08 05:25:31 UTC 2024 using Jira 9.7.1#970001-sha1:2222b88b221c4928ef0de3161136cc90c8356a66.