We have received recently some complaints about the non-retry behaviour on StaleConfig error when running a count command.

When mongos receives a count command, it's sending out a scatter-gather request to all shards owning chunks. Since the scatter-gather utility is not retrying on StaleConfig errors, the StaleConfig error is being reported to the user. 

After browsing the code, we have seen there are several commands using the same scatterGatherVersionedTargetByRoutingTable utility, so they are likely to don't reply on StaleConfig either.

The aim of this ticket is to investigate more deeply which commands are not retrying on StaleConfig and to figure out how to solve this.