Increase conection suddenly on MongoD

Hi , good time
i have big problem during last 2 month . since 2 month ago sometime we have huge connection ( more than 20K) as unusual on primary and shard0
as we have checked there is not any abnormal TPS or queries or identified time pattern.
now i have below enquiries :

  1. is it related to version ?
  2. the main error is REST SERVICE INVOCATION , what’s it?
  3. is it belong to any object?
    version is : 3.2.6
    1 primary and 2 secondary

Hi @Soroush_Sadegh_Bayan and welcome to the MongoDB community!!

The current version you are using is quiet old (released around 2017) and there have been security issues related to this version.

Hence, the recommendation would be to update to the oldest supported version which is 4.4. Please refer to the legacy support documentation for more.

Can you please share the complete error message that you are seeing in the deployment?

Can you also share more details on how the does your deployment looks like?

Also, please share the output for db.getCmdLineOpts() and db.version() on the affected node.

Let us know if you have any further questions.

Best Regards