[SERVER-49004] Router returns an empty result, although the collection contains data. Created: 22/Jun/20  Updated: 27/Oct/23  Resolved: 12/Jul/20

Status: Closed
Project: Core Server
Component/s: Querying
Affects Version/s: 4.0.16
Fix Version/s: None

Type: Bug Priority: Major - P3
Reporter: Florian Hulliger Assignee: Dmitry Agranat
Resolution: Community Answered Votes: 0
Labels: None
Remaining Estimate: Not Specified
Time Spent: Not Specified
Original Estimate: Not Specified

Operating System: ALL
Steps To Reproduce:

We have not found a way to reproduce the problem because it is very rare.

 

Participants:

 Description   

From time to time we face the problem that a router does not know a collection although the collection exists and has data.

A simple .find() operation returns a empty result. Over another router the same .find() operation returns the expected records.

After a restart of the router, the query works as expected.

 



 Comments   
Comment by Dmitry Agranat [ 12/Jul/20 ]

No problem florian.hulliger@gmail.com, I will go ahead and close this case. If you'll reproduce this issue on supported MongoDB version, please open a new ticket.

Regards,
Dima

Comment by Florian Hulliger [ 10/Jul/20 ]

Hi Dima

I checked with our ICT team, and its true. They checked the behavior on the wrong cluster. I should have double checked that by myself. Thanks for finding this out.

Regards,

Florian

Comment by Dmitry Agranat [ 09/Jul/20 ]

Hi florian.hulliger@gmail.com, this is MongoDB version from the logs you've uploaded:

2020-06-08T13:07:37.372+0000 I SHARDING [mongosMain] mongos version v3.4.20
2020-06-08T13:07:37.372+0000 I CONTROL  [mongosMain] git version: 447847d93d6e0a21b018d5df45528e815c7c13d8
2020-06-08T13:07:37.372+0000 I CONTROL  [mongosMain] OpenSSL version: OpenSSL 1.0.2g  1 Mar 2016
2020-06-08T13:07:37.372+0000 I CONTROL  [mongosMain] allocator: tcmalloc
2020-06-08T13:07:37.372+0000 I CONTROL  [mongosMain] modules: none
2020-06-08T13:07:37.372+0000 I CONTROL  [mongosMain] build environment:
2020-06-08T13:07:37.372+0000 I CONTROL  [mongosMain]     distmod: ubuntu1604
2020-06-08T13:07:37.372+0000 I CONTROL  [mongosMain]     distarch: x86_64
2020-06-08T13:07:37.372+0000 I CONTROL  [mongosMain]     target_arch: x86_64
2020-06-08T13:07:37.372+0000 I CONTROL  [mongosMain] db version v3.4.20
2020-06-08T13:07:37.372+0000 I CONTROL  [mongosMain] git version: 447847d93d6e0a21b018d5df45528e815c7c13d8
2020-06-08T13:07:37.372+0000 I CONTROL  [mongosMain] OpenSSL version: OpenSSL 1.0.2g  1 Mar 2016
2020-06-08T13:07:37.372+0000 I CONTROL  [mongosMain] allocator: tcmalloc
2020-06-08T13:07:37.372+0000 I CONTROL  [mongosMain] modules: none
2020-06-08T13:07:37.372+0000 I CONTROL  [mongosMain] build environment:
2020-06-08T13:07:37.372+0000 I CONTROL  [mongosMain]     distmod: ubuntu1604
2020-06-08T13:07:37.372+0000 I CONTROL  [mongosMain]     distarch: x86_64
2020-06-08T13:07:37.372+0000 I CONTROL  [mongosMain]     target_arch: x86_64

Comment by Florian Hulliger [ 09/Jul/20 ]

Hi Dima

Thats just the version of the client console application. The version of the server is 4.0.16.The behavior was the same in a newer console or when running over Studio 3T.

Regards,

Florian

Comment by Dmitry Agranat [ 08/Jul/20 ]

Hi florian.hulliger@gmail.com,

You've indicated that the version you are using is 4.0.16 but based on the provided logs it is db version v3.4.20. As 3.4 version has reached EOL, can you reproduce this issue by using one of the supported versions?

Thanks,
Dima

Comment by Florian Hulliger [ 25/Jun/20 ]

Hi Carl

I uploaded the two files. The collection with no result was: D_IQ_CHEOR.PROD_RUN_10722

Thanks for having a look!

Regards,

Florian

Comment by Carl Champain (Inactive) [ 24/Jun/20 ]

Sure, we'll take a look at the mongos.log files!

We've created a secure upload portal for you. Files uploaded to this portal are visible only to MongoDB employees and are routinely deleted after some time.

Thank you,
Carl
 

Comment by Florian Hulliger [ 24/Jun/20 ]

Hi 

We stored the log of the mongos before and after the restart.

We don't have the mongod log any longer. Would it be enough to provide just the mongos log?

And do you provide a possibility to upload the log on a private channel?

Regards,

Florian

Comment by Carl Champain (Inactive) [ 23/Jun/20 ]

Hi florian.hulliger@gmail.com,

Thank you for the report.
Can you please provide the mongod.log and mongos.log files covering this behavior?

Kind regards,
Carl

Generated at Thu Feb 08 05:18:40 UTC 2024 using Jira 9.7.1#970001-sha1:2222b88b221c4928ef0de3161136cc90c8356a66.