FCV is automatically advanced to 4.4 on ARBITER after upgrading replica set from 4.2 on Windows

Ops and Admin
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1

Hi Experts,

We have 3 node replica set(PSA) on Windows 2016 servers with MongoDB version 4.2.
Its featureCompatibilityVersion is 4.2 on all nodes before upgrade. Once it is upgraded to 4.4 all expect ARBITER remained at FCV 4.2 but on ARBITER it is automatically advanced to 4.4. Even if we set it back to 4.2 on primary using set command it is not replicating to ARBITER. is it default behavior or a known issue in version 4.4. This looks strange. Can we just disregard it.

Thanks

2

FCV is only for data bearing nodes
Actually it’s value should be less than other nodes
I think you can ignore
The command set FCV cannot be replicated to arbiter

3

Hi @Ramachandra_Tummala ,

Thanks for the quick update.

I did not get what you meant by “Actually it’s value should be less than other nodes”.

Do you mean FCV should be less on ARBITER.

Thanks

4

Hi @Ramachandra_Tummala ,

My issue is similar to the one mentioned in the below thread.

Thanks

5

Hi ,

And we have below doc:
https://jira.mongodb.org/browse/DOCS-13029
https://jira.mongodb.org/browse/SERVER-60869

We also have these: