MongoDB Slow Query

slow query log in MongoDB

1. turn on the query log .

(1) Dynamic Open , can be selective to the specified DB turn on slow query log , However, the slow query log is manually opened after the server restarts.

Db.setprofilinglevel (1,300)

The Setprofilinglevel has two parameters , the first parameter represents the slow query log switch ( The value that can be used is 0,1,2

0: The slow query log is turned off , 1: indicates that the slow query log is turned on , 2: indicates that all queries in the database are logged.

The second parameter is a slow query threshold , in milliseconds , and by default , the threshold is 100ms.

(2). in the configuration file, open , Be permanently in effect. Valid for all data DB

Add two parameters to the MONGO configuration file to permanently open the slow query.

Profile: indicates a slow query log switch .

SLOWMS: Slow query log threshold.

corresponds to the two parameters in the Setprofilinglevel.

2. View server slow query log status

Db.getprofilingstatus ()

Rs0:secondary> Db.getprofilingstatus ();

{"was": 1, "SLOWMS": 100}

Db.getprofilinglevel ()

Rs0:secondary> Db.getprofilinglevel ()

1

3. view the full query log.

In general , a collection (system.profile) is generated below each DB when the slow query log is turned on .

This collection records all query records for the current database query time exceeding the threshold.

Rs0:primary> db.system.profile.find ({ns:/^gow/}). Limit (1)

{"OP": "Update",

"NS": "Gow.broadcasts",

"Query": {"_id": ObjectId ("54b73af6bab3047b5593c456")},

"Updateobj": {"_id": ObjectId ("54b73af6bab3047b5593c456"), "content": " each new stone "},

"nscanned": 0,

"Nscannedobjects": 0,

"Nmatched": 1,

"Nmodified": 0,

"Upsert": true,

"Keyupdates": 0,

"Numyield": 0,

"Lockstats": {"Timelockedmicros": {"R": Numberlong (0), "W": Numberlong (10)}},

"Millis": 157,

"Execstats": {},

"TS": Isodate ("2015-01-26t19:05:00.118z"),

"Client": "10.136.3.117",

"AllUsers": [{"User": "Root", "db": "admin"}], "User": "[email protected]"}

Key value Explanation:

OP: The type of operation.

NS: Collection of objects performing actions

Millis: Operation takes time, milliseconds

Client: The customer service side that performs the operation.

AllUsers: mongodb account to perform the operation

TS: timestamp ( The time the operation occurred )

This article is from the "SQL Server MySQL" blog, so be sure to keep this source http://dwchaoyue.blog.51cto.com/2826417/1614281

MongoDB Slow Query