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Type:
Bug
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Resolution: Done
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Priority:
Major - P3
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None
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Affects Version/s: 2.4.2
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Component/s: None
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None
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Environment:Windows 2008 R2
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Fully Compatible
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Windows
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None
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3
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None
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None
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None
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None
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None
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None
Restart mongodb, issue touch command for a collection's data and indexes.
Mongostat output taken while touch was running is shown below (shows data is page faulted into memory and resident goes up)
insert query update delete getmore command flushes mapped vsize res faults locked db idx miss % qr|qw ar|aw netIn netOut conn time
*0 *0 *0 *0 0 2|0 0 80m 308m 39m 2 local:0.0% 0 0|0 0|0 115b 5k 3 10:38:43
*0 *0 *0 *0 0 2|0 0 80m 308m 39m 0 local:0.0% 0 0|0 0|0 115b 5k 3 10:38:44
*0 *0 *0 *0 0 2|0 0 80m 308m 39m 0 local:0.0% 0 0|0 0|0 115b 5k 3 10:38:45
*0 *0 *0 *0 0 2|0 0 80m 308m 39m 0 local:0.0% 0 0|0 0|0 115b 5k 3 10:38:46
*0 *0 *0 *0 0 2|0 0 80m 308m 39m 0 local:0.0% 0 0|0 0|0 115b 5k 3 10:38:47
*0 *0 *0 *0 0 2|0 0 80m 308m 39m 0 local:0.0% 0 0|0 0|0 115b 5k 3 10:38:48
*0 *0 *0 *0 0 3|0 0 80m 309m 39m 15 local:0.0% 0 0|0 0|0 203b 5k 4 10:38:49
*0 *0 *0 *0 0 2|0 0 80m 309m 39m 2 local:0.0% 0 0|0 0|0 115b 5k 4 10:38:50
*0 *0 *0 *0 0 5|0 0 80m 309m 39m 0 local:0.0% 0 0|0 0|0 286b 6k 4 10:38:51
*0 *0 *0 *0 0 2|0 0 80m 309m 39m 0 local:0.0% 0 0|0 0|0 115b 5k 4 10:38:52
insert query update delete getmore command flushes mapped vsize res faults locked db idx miss % qr|qw ar|aw netIn netOut conn time
*0 *0 *0 *0 0 2|0 0 80m 309m 39m 0 local:0.0% 0 0|0 0|0 115b 5k 4 10:38:53
*0 *0 *0 *0 0 4|0 0 544m 1.21g 83m 11268 .:0.2% 0 0|0 0|0 290b 5k 4 10:38:54
*0 *0 *0 *0 0 2|0 0 544m 1.21g 83m 5 xxxx:0.0% 0 0|0 0|0 115b 7k 4 10:38:55
*0 *0 *0 *0 0 2|0 0 544m 1.21g 83m 32 xxxx:0.0% 0 0|0 0|0 115b 7k 4 10:38:56
*0 *0 *0 *0 0 2|0 0 544m 1.21g 83m 0 xxxx:0.0% 0 0|0 0|0 115b 7k 4 10:38:57
*0 *0 *0 *0 0 2|0 0 544m 1.21g 83m 0 xxxx:0.0% 0 0|0 0|0 115b 7k 4 10:38:58
*0 *0 *0 *0 0 2|0 0 544m 1.21g 83m 0 xxxx:0.0% 0 0|0 0|0 115b 7k 4 10:38:59
*0 *0 *0 *0 0 2|0 0 544m 1.21g 83m 2 xxxx:0.0% 0 0|0 0|0 115b 7k 4 10:39:00
Run query db.collection.find() - this query runs slow and there is evidence from profiling of high timeAcquiringMicros , r and high numYield while this query takes place.
{
"op" : "getmore",
"ns" : "xxxx",
"query" : { },
"cursorid" : NumberLong("369564976120489"),
"ntoreturn" : 0,
"keyUpdates" : 0,
"numYield" : 185,
"lockStats" : {
"timeLockedMicros" : {
"r" : NumberLong(5482),
"w" : NumberLong(0)
},
"timeAcquiringMicros" : {
"r" : NumberLong(2970221),
"w" : NumberLong(3)
}
},
"nreturned" : 589,
"responseLength" : 712048,
"millis" : 2970,
"ts" : ISODate("2013-04-23T09:18:57.007Z"),
"client" : "10.194.144.71",
"allUsers" : [],
"user" : ""
}
Mongostat shows page faulting.
Run same query again - query runs fast. Mongostat shows page faulting.
RAM is 4GB, collection size is 13MB data, 2MB indexes.
Dedicated VM used for testing with no other queries running.