Major - P3 We have a sharded cluster. One of our primaries had several queued up RangeDeletes from chunks being moved off due to chunk migration. Typically the log shows the following for deleting a chunk after the migration of the chunk to a new primary:
1. Deleter starting delete for: <namespace> from {<begin-range-of-chunk>} -> {<end-range-of-chunk>}, with opId: xxxxxxxx 2. Some time later...Helpers::removeRangeUnlocked time spent waiting for replication: x ms 3. rangeDeleter deleted n documents for <namespace> from {<begin-range-of-chunk>} -> {<end-range-of-chunk>}
However, occasionally we see:
1. Deleter starting delete for: ... (normal log statement as above) 2. some time later... Error encountered while trying to delete range: Error encountered while deleting range: ns<namespace> from {<begin-range-of-chunk>} -> {<end-range-of-chunk>}, cause by: :: caused by :: 112 WriteConflict 3. No further log statements by the RangeDeleter for the specified chunk range that experienced a write conflict.
I can only assume that the Write Conflict was not handled properly, and the documents were never successfully deleted??