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Type:
Bug
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Resolution: Incomplete
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Priority:
Major - P3
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None
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Affects Version/s: None
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Component/s: Performance, Write Ops
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Storage Execution
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Fully Compatible
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ALL
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0
Mongo-perf shows a large regression on all of the update tests sometime between 3.1.2 and 3.1.4 on wiredTiger, probably over multiple commits, and another ~4% drop since 3.1.4. On WiredTiger and MMAPv1, although the regression shows earlier on wiredTiger.
WiredTiger Results
MMAPv1 Results
Two simplified shell based reproductions.
Update.MultiUpdate.Uncontended.TwoDocs.NoIndex
var setupTestUncontendedTwoDocs = function( collection ) { collection.drop(); var docs = []; for ( var i = 0; i < 4800; i++ ) { docs.push( { _id : i , x : 0 } ); } collection.insert(docs); collection.getDB().getLastError(); }; use test0 setupTestUncontendedTwoDocs(db.MultiUpdate_Uncontended_TwoDocs_NoIndex0) benchRun({"ops":[{"op":"update","multi":true,"query":{"_id":{"$in":[{"#RAND_INT_PLUS_THREAD":[0,100]},{"#RAND_INT_PLUS_THREAD":[0,100]}]}},"update":{"$inc":{"x":1}},"ns":"test0.MultiUpdate_Uncontended_TwoDocs_NoIndex0","safe":false,"w":0,"j":false,"writeCmd":true}],"seconds":5,"host":"127.0.0.1:27017","parallel":8})
Update.FieldAtOffset
var setup = function( collection ) { collection.drop(); var kFieldCount = 512; // Build the document and insert several copies. var toInsert = {}; for (var i = 0; i < kFieldCount; i++) { toInsert["a_" + i.toString()] = "a"; } var docs = []; for (var i = 0; i < 100; i++) { docs.push(toInsert); } collection.insert(docs); collection.getDB().getLastError(); } use test0 setup(db.Update_FieldAtOffset0) benchRun({"ops":[{"op":"update","multi":true,"query":{},"update":{"$set":{"a_256":"a"}},"ns":"test0.Update_FieldAtOffset0","safe":false,"w":0,"j":false,"writeCmd":true},{"op":"update","multi":true,"query":{},"update":{"$set":{"a_256":"aa"}},"ns":"test0.Update_FieldAtOffset0","safe":false,"w":0,"j":false,"writeCmd":true}],"seconds":5,"host":"127.0.0.1:27017","parallel":8})