After upgrading mongodb from version 4.4.x to 5.0.14 in a company I'm working for, we have found thousands of errors in our logs. All of them refers to the same issue "Plan executor error during findAndModify".
In our case, we use findAndModify in a spring-boot application to take first pending job from a queue. This operation is executed concurrently on many app instances (5-10 threads each).
Here you can find sample project simulating our use case: https://github.com/gebus93/mongo-find-and-modify-issue
In this project I created 3 tests to compare the behaviour of mongo 4, 5 and 6. Each test runs a specific mongodb in a docker container and executes the same test case.
Mongodb 4.4.19 doesn't log any write conflict during the test, but starting from mongo 5.0.x error logs are produced on every test run.
{"t":{"$date":"2023-03-02T11:47:14.567+00:00"},"s":"W", "c":"COMMAND", "id":23802, "ctx":"conn13","msg":"Plan executor error during findAndModify","attr":{"error":{"code":112,"codeName":"WriteConflict","errmsg":"WriteConflict error: this operation conflicted with another operation. Please retry your operation or multi-document transaction."},"stats":{"stage":"UPDATE","nReturned":0,"executionTimeMillisEstimate":0,"works":104,"advanced":0,"needTime":102,"needYield":1,"saveState":1,"restoreState":1,"failed":true,"isEOF":0,"nMatched":0,"nWouldModify":0,"nWouldUpsert":0,"inputStage":{"stage":"SORT","nReturned":1,"executionTimeMillisEstimate":0,"works":103,"advanced":1,"needTime":102,"needYield":0,"saveState":2,"restoreState":1,"isEOF":0,"sortPattern":{"creationTime":1},"memLimit":104857600,"limitAmount":1,"type":"default","totalDataSizeSorted":0,"usedDisk":false,"inputStage":{"stage":"COLLSCAN","filter":{"status":{"$eq":"NEW"}},"nReturned":53,"executionTimeMillisEstimate":0,"works":102,"advanced":53,"needTime":48,"needYield":0,"saveState":2,"restoreState":1,"isEOF":1,"direction":"forward","docsExamined":100}}},"cmd":{"findAndModify":"jobs","query":{"status":"NEW"},"sort":{"creationTime":1},"update":{"$set":{"status":"PROCESSING"}},"new":false}}}
Is this behaviour expected?
Why is there a difference between mongodb 4 and the others?
- is caused by
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SERVER-43821 Fail in query execution by throwing rather than the FAILURE state code
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- Closed
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- is related to
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SERVER-80317 DuplicateKey error message is logged from findAndModify after 5.0 upgrade
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- Closed
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