ClusterCountCmd::run uses scatterGatherVersionedTargetByRoutingTable, which throws on routing errors. The routing error exceptions are caught in mongos's/mongoq's service entry point, where mongos/mongoq marks the appropriate routing cache entry as stale and retries the command by calling that function recursively until retries are exhausted.

This ticket should:

• Update scatterGatherVersionedTargetByRoutingTable to also throw on TenantMigrationAborted
• Update mongos's/mongoq's service entry point to recursively call run() on TenantMigrationAborted
• Add a test that mongos/mongoq retries the count command internally on TenantMigrationAborted.
  • The test should be similar to the testRejectBlockedWritesAfterMigrationAborted test case in that it should:
    • set the pauseTenantMigrationBeforeLeavingBlockingState and abortTenantMigrationBeforeLeavingBlockingState failpoints on the replica set primary
    • start a tenant migration against the replica set primary
    • wait for the first failpoint to be hit
    • run the count command
    • wait for the replica set primary to report that it is blocking a read
    • disable the first failpoint to allow the count command to continue
    • assert that the count command worked
  • However, the test should run the count command against mongos/mongoq instead of against the replica set primary.