> db.test.drop() true > db.test.insert({_id:0}) WriteResult({ "nInserted" : 1 }) > benchRun({ "ops" : [ { "op" : "update" , "ns" : "test.test" , "query" : { "_id" : 0 }, "writeCmd" : true , "update" : { "$adsfadsf" : { "x" : 1 } } } ], "seconds" : 0.1, host: db.getMongo().host }) { "note" : "values per second" , "errCount" : NumberLong(0), "trapped" : "error: not implemented" , "updateLatencyAverageMicros" : 282.6798866855524, "totalOps" : NumberLong(353), "totalOps/s" : 3519.0557366589906, "findOne" : 0, "insert" : 0, "delete" : 0, "update" : 3519.0557366589906, "query" : 0, "command" : 0 } > db.test.find({_id:0}) { "_id" : 0 } > benchRun({ "ops" : [ { "op" : "update" , "ns" : "test.test" , "query" : { "_id" : 0 }, "writeCmd" : true , "update" : { "$inc" : { "x" : 1 } } } ], "seconds" : 0.1, host: db.getMongo().host }) { "note" : "values per second" , "errCount" : NumberLong(0), "trapped" : "error: not implemented" , "updateLatencyAverageMicros" : 195.5078431372549, "totalOps" : NumberLong(510), "totalOps/s" : 5087.992338082126, "findOne" : 0, "insert" : 0, "delete" : 0, "update" : 5087.992338082126, "query" : 0, "command" : 0 } > db.test.find({_id:0}) { "_id" : 0, "x" : 510 } > 2019-10-31T14:45:40.735+1100 D2 COMMAND [conn13] run command test.$cmd { update: "test", writeConcern: {}, $db: "test" } 2019-10-31T14:45:40.735+1100 D1 - [conn13] User Assertion: FailedToParse: Unknown modifier: $adsfadsf. Expected a valid update modifier or pipeline-style update specified as an array src/mongo/db/update/update_driver.cpp 81 2019-10-31T14:45:40.735+1100 I WRITE [conn13] update test.test appName: "BenchRun" command: { q: { _id: 0.0 }, u: { $adsfadsf: { x: 1.0 } }, multi: false, upsert: false } numYields:0 ok:0 errMsg:"Unknown modifier: $adsfadsf. Expected a valid update modifier or pipeline-style update specified as an array" errName:FailedToParse errCode:9 locks:{} 0ms 2019-10-31T14:45:40.735+1100 I COMMAND [conn13] command test.$cmd appName: "BenchRun" command: update { update: "test", writeConcern: {}, $db: "test" } numYields:0 reslen:228 locks:{ ParallelBatchWriterMode: { acquireCount: { r: 1 } }, ReplicationStateTransition: { acquireCount: { w: 1 } }, Global: { acquireCount: { r: 1 } } } protocol:op_msg 0ms