20110514 mongo dbチューニング
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The document provides tips and explanations for various MongoDB commands and operations including explain, hint, setProfilingLevel, currentOp, and mongostat. It discusses using indexes to optimize queries, setting profiling levels to log slow queries, using currentOp to view currently running operations, and using mongostat to view MongoDB server statistics.
![( )
> db.logs.find({uid:"b3iVxMGIEc3xxxxY"}).explain();
{
"cursor" : "BtreeCursor uid_1",
"nscanned" : 3,
"nscannedObjects" : 3,
"n" : 3,
"millis" : 6,
”uid_1”
"nYields" : 0, 6ms
"nChunkSkips" : 0,
3 3
"isMultiKey" : false,
"indexOnly" : false,
"indexBounds" : {
"uid" : [
[
"b3iVxMGIEc3xxxxY",
"b3iVxMGIEc3xxxxY"
]
]
}
}](https://image.slidesharecdn.com/20110514mongodb-110513234802-phpapp01/85/20110514-mongo-db-15-320.jpg)
![slowms
! mongod slowms
ms
mongod
mongod --logpath=/var/log/mongodb/mongodb.log --logappend –slowms 500
Sat May 14 02:25:53 [conn16] query logdb.$cmd ntoreturn:1
command: { count: "logs", query: { path: "/index.html" }, fields: {} } reslen:64 3116ms](https://image.slidesharecdn.com/20110514mongodb-110513234802-phpapp01/85/20110514-mongo-db-18-320.jpg)
![> db.currentOp();
{
"inprog" : [
{
"opid" : 272,
"active" : true,
"lockType" : "read",
"waitingForLock" : false,
"secs_running" : 20,
"op" : "query",
"ns" : "logdb.logs",
"query" : {
"count" : "logs",
"query" : {
"month" : "2010/02"
},
"fields" : {
}
},
"client" : "127.0.0.1:59394",
"desc" : "conn"
}]}](https://image.slidesharecdn.com/20110514mongodb-110513234802-phpapp01/85/20110514-mongo-db-22-320.jpg)
![!
• db.c.find( {x:10,y:20} ), using index {x:1,y:1}
• db.c.find( {x:10,y:20} ), using index {x:1,y:-1}
• db.c.find( {x:{$in:[10,20]},y:20} ), using index {x:1,y:1}
• db.c.find().sort( {x:1,y:1} ), using index {x:1,y:1}
• db.c.find().sort( {x:-1,y:1} ), using index {x:1,y:-1}
• db.c.find( {x:10} ).sort( {y:1} ), using index {x: 1,y:1}](https://image.slidesharecdn.com/20110514mongodb-110513234802-phpapp01/85/20110514-mongo-db-25-320.jpg)
![hint
> db.logs.find({uid:"f2RNwtj34m3xxxxB" , path : "/index.html"}).hint({uid:1}).explain();
{
"cursor" : "BtreeCursor uid_1",
"nscanned" : 95,
"nscannedObjects" : 95,
"n" : 35,
"millis" : 3,
"nYields" : 0,
"nChunkSkips" : 0,
"isMultiKey" : false,
"indexOnly" : false,
"indexBounds" : {
"uid" : [
[
"f2RNwtj34m3xxxxB",
"f2RNwtj34m3xxxxB"
]
]
}
}](https://image.slidesharecdn.com/20110514mongodb-110513234802-phpapp01/85/20110514-mongo-db-27-320.jpg)
![hint
> db.logs.find({uid:"f2RNwtj34m3xxxxB" , path : "/index.html"}).hint({uid:1 , path:1}).explain();
{
"cursor" : "BtreeCursor uid_1_path_1",
"nscanned" : 35,
"nscannedObjects" : 35,
"n" : 35,
"millis" : 0,
"nYields" : 0,
"nChunkSkips" : 0,
"isMultiKey" : false,
"indexOnly" : false,
"indexBounds" : {
"uid" : [
[
"f2RNwtj34m3xxxxB",
"f2RNwtj34m3xxxxB"
]
],
( )
}
}](https://image.slidesharecdn.com/20110514mongodb-110513234802-phpapp01/85/20110514-mongo-db-28-320.jpg)
![collection
! getIndexKeys()
> db.logs.getIndexKeys();
[ { "_id" : 1 }, { "uid" : 1 }, { "uid" : 1, "path" : 1 } ]](https://image.slidesharecdn.com/20110514mongodb-110513234802-phpapp01/85/20110514-mongo-db-31-320.jpg)
![! db.currentOp opid db.killOp(opid)
> db.currentOp();
{
"inprog" : [
{
"opid" : 308,
"active" : true,
"lockType" : "read",
"waitingForLock" : false,
"secs_running" : 11,
"op" : "query",
"ns" : "logdb.logs",
( )
}
]
}
> db.killOp(308);
{ "info" : "attempting to kill op" }](https://image.slidesharecdn.com/20110514mongodb-110513234802-phpapp01/85/20110514-mongo-db-32-320.jpg)
20110514 mongo dbチューニング
- 1. MongoDB id:matsuou1
- 2. ! ! ! ! ! ! Tips !
- 3. ! ID matsuou1 ! ! ! ! ! Oracle PostgreSQL ! MongoDB Hadoop R
- 4. 1. 2. 3. 4.
- 6. ! ! RDBMS !
- 7. ! !
- 8. MongoDB ! ! CPU ! ! JOIN !
- 9. • • 100 insert update delete • • nscanned 10 •
- 12. ! explain > db.logs.find({uid:"a10Sty5jqqiyxxxx2"}).explain(); { "cursor" : "BasicCursor", "nscanned" : 2669511, "nscannedObjects" : 2669511, "n" : 3, "millis" : 6100, "nYields" : 0, "nChunkSkips" : 0, "isMultiKey" : false, "indexOnly" : false, "indexBounds" : { } }
- 13. cursor BasicCursor BasicCursor or BtreeCursor nscanned 14 nscannedObjects 14 n 14 millis 9 ms nYields 0 nChunkSkips 0 Chunk isMultiKey false indexOnly false indexBounds scanAndOrder allPlans
- 14. ( ) > db.logs.find({uid:"a10Sty5jqqiyxxxx2"}).explain(); { "cursor" : "BasicCursor", "nscanned" : 2669511, "nscannedObjects" : 2669511, "n" : 3, "millis" : 6100, "nYields" : 0, 6100ms "nChunkSkips" : 0, 3 266 "isMultiKey" : false, "indexOnly" : false, "indexBounds" : { } }
- 15. ( ) > db.logs.find({uid:"b3iVxMGIEc3xxxxY"}).explain(); { "cursor" : "BtreeCursor uid_1", "nscanned" : 3, "nscannedObjects" : 3, "n" : 3, "millis" : 6, ”uid_1” "nYields" : 0, 6ms "nChunkSkips" : 0, 3 3 "isMultiKey" : false, "indexOnly" : false, "indexBounds" : { "uid" : [ [ "b3iVxMGIEc3xxxxY", "b3iVxMGIEc3xxxxY" ] ] } }
- 17. ! ! slowms ! ! db.setProfilingLevel(level,slowms) !
- 18. slowms ! mongod slowms ms mongod mongod --logpath=/var/log/mongodb/mongodb.log --logappend –slowms 500 Sat May 14 02:25:53 [conn16] query logdb.$cmd ntoreturn:1 command: { count: "logs", query: { path: "/index.html" }, fields: {} } reslen:64 3116ms
- 19. setProfilingLevel setProfilingLevel (level,slowms) > db.setProfilingLevel(1,500); { "was" : 1, "slowms" : 100, "ok" : 1 } 100ms
- 20. setProfilingLevel system.profile > db.system.profile.find(); { "ts" : ISODate("2011-05-01T03:40:04.462Z"), "info" : "query logdb.logs reslen:192 nscanned:2669511 nquery: { uid: "b2kwyYCXn3b5Scpr" } nreturned:1 6686ms", "millis" : 6686 } ts millis info query query query nscanned reslen nreturned
- 21. db.currentOp opid ID KillOp op query update ns query lockType waitingForLock client desc
- 22. > db.currentOp(); { "inprog" : [ { "opid" : 272, "active" : true, "lockType" : "read", "waitingForLock" : false, "secs_running" : 20, "op" : "query", "ns" : "logdb.logs", "query" : { "count" : "logs", "query" : { "month" : "2010/02" }, "fields" : { } }, "client" : "127.0.0.1:59394", "desc" : "conn" }]}
- 23. slowms db.setProfilingLevel collection system.profile capped collection db.currentOp MongoDB
- 24. Tips
- 25. ! • db.c.find( {x:10,y:20} ), using index {x:1,y:1} • db.c.find( {x:10,y:20} ), using index {x:1,y:-1} • db.c.find( {x:{$in:[10,20]},y:20} ), using index {x:1,y:1} • db.c.find().sort( {x:1,y:1} ), using index {x:1,y:1} • db.c.find().sort( {x:-1,y:1} ), using index {x:1,y:-1} • db.c.find( {x:10} ).sort( {y:1} ), using index {x: 1,y:1}
- 26. hint ! hint !
- 27. hint > db.logs.find({uid:"f2RNwtj34m3xxxxB" , path : "/index.html"}).hint({uid:1}).explain(); { "cursor" : "BtreeCursor uid_1", "nscanned" : 95, "nscannedObjects" : 95, "n" : 35, "millis" : 3, "nYields" : 0, "nChunkSkips" : 0, "isMultiKey" : false, "indexOnly" : false, "indexBounds" : { "uid" : [ [ "f2RNwtj34m3xxxxB", "f2RNwtj34m3xxxxB" ] ] } }
- 28. hint > db.logs.find({uid:"f2RNwtj34m3xxxxB" , path : "/index.html"}).hint({uid:1 , path:1}).explain(); { "cursor" : "BtreeCursor uid_1_path_1", "nscanned" : 35, "nscannedObjects" : 35, "n" : 35, "millis" : 0, "nYields" : 0, "nChunkSkips" : 0, "isMultiKey" : false, "indexOnly" : false, "indexBounds" : { "uid" : [ [ "f2RNwtj34m3xxxxB", "f2RNwtj34m3xxxxB" ] ], ( ) } }
- 29. mongostat mongostat
- 30. mongostat inserts insert / query query / update update / delete delete / getmore getmore / command command / flushes fsync flush / mapped Map MB visze MB res MB faults / locked Idx miss qr|qw read | write ar|aw read | write netIn In bits netOut Out bits conn
- 31. collection ! getIndexKeys() > db.logs.getIndexKeys(); [ { "_id" : 1 }, { "uid" : 1 }, { "uid" : 1, "path" : 1 } ]
- 32. ! db.currentOp opid db.killOp(opid) > db.currentOp(); { "inprog" : [ { "opid" : 308, "active" : true, "lockType" : "read", "waitingForLock" : false, "secs_running" : 11, "op" : "query", "ns" : "logdb.logs", ( ) } ] } > db.killOp(308); { "info" : "attempting to kill op" }
- 33. ! ! ! explain ! ! slowms ! setProfilingLevel ! db.currentOP ! Tips ! ! Hint ! mongostat