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Description of problem:

The switch to the wiredTiger Storage Engine, offered has a great performance improvement has brought also a big memory issue: as reported in upstream documentation[0] the engine can consume up to half of all memory for its local cache.

[0] https://docs.mongodb.com/manual/core/wiredtiger/

In the solution is reported how to limit the cache size:

https://access.redhat.com/solutions/4505561

but that value is not tested. Customer are left with no reasonable/tested/reference value.

This situation leave customers with two bad options:
- the risk that OOM killer will stop Mongo in case of resources contention
- the risk to affect performance by choosing an arbitrary value for the cache size


Version-Release number of selected component (if applicable):
Sat 6.5+


Actual results:
No guidance on how to avoid mongo taking possession of a Sat6

Expected results:
Having guidance with documented values according to host numbers or other parameters, in a shape like https://github.com/RedHatSatellite/satellite-support/tree/master/tuning-profiles

*** This bug has been marked as a duplicate of bug 1798668 ***