MongoDB | 2608533

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The block_chunk_migrations_without_hashed_shard_key_index test migrates chunks between shards and finishes with the following sequence: wait for balancer round to finish wait until a chunk show up on the recipient shard check the shardVersion equivalence on CSRS and the donor shard The checking might fail due to a race condition if a stepdown happens during the balancer round of the CSRS. In that case the following happens: CSRS stepdown -> balancer round ends donor commands the recipient to update the local catalog (new chunks show up) donor commits the change on CSRS CSRS updates shardVersion check the shardVersion equivalence on CSRS and the donor shard CSRS responses the update -> donor has updated shardVersion in this scenario the check happens just in the wrong time causing a fail in the test. the intention was to eliminate this race condition with the wait for balancer round to finish but if a CSRS stepdown happens the race condition could occur. Recommended solution: Wait for the migrations to finish with the _shardsvrJoinMigrations internal command before the shardVersion checking (after the balancer is stopped) before

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