clearJumboFlag

On this page本页内容

Definition定义

clearJumboFlag

Available starting in 4.2.3 and 4.0.15

Clears the jumbo flag for a chunk. To use the command, issue the clearJumboFlag command on a mongos instance.

Syntax语法

clearJumboFlag has the following syntaxes:

db.adminCommand( {
   clearJumboFlag: "<database>.<collection>",
   bounds : <array>
} )

-OR-

// Cannot use for collections with hashed shard keys

db.adminCommand( {
   clearJumboFlag: "<database>.<collection>",
   find : <query>
} )

Command Fields

The clearJumboFlag command takes the following fields as arguments:

Field字段Type类型Description描述
clearJumboFlag string

The namespace of the sharded collection with the jumbo chunk(s).

Specify the collection’s full namespace, including the database name (i.e. “<database>.<collection>”)

bounds array

The exact bounds of a specific chunk. The array must consist of two documents that specify the lower and upper shard key values of a chunk to move:

[ { <shardKey> : <minValue> },{ <shardKey> : <maxValue> } ]

Note

find document

A specific shard key and its value contained in the jumbo chunk.

{ <shardKey> : <value> }

Note

Access Control

On systems running with authorization, the user must have the clearJumboFlag privilege actions on the { db: "", collection: "" } resource.

The built-in role clusterManager provides the appropriate privileges.

Example示例

Clear Jumbo Flag for a Chunk (Range-Based Shard Key)

The sh.status() includes the following sh.status.databases.<collection>.chunk-details for the test.jumbo collection.

... // Content omitted for brevity

test.jumbo
         shard key: { "x" : 1 }
         unique: false
         balancing: true
         chunks:
                 shardA   2
                 shardB   2
         { "x" : { "$minKey" : 1 } } -->> { "x" : 1 } on : shardB Timestamp(3, 0)
{ "x" : 1 } -->> { "x" : 2 } on : shardA Timestamp(6, 1) jumbo{ "x" : 2 } -->> { "x" : 3 } on : shardA Timestamp(5, 1) jumbo         { "x" : 3 } -->> { "x" : { "$maxKey" : 1 } } on : shardB Timestamp(6, 0)

The following clearJumboFlag command specifies the bounds of the { "x" : 1 } -->> { "x" : 2 } chunk:

db.adminCommand( {
   clearJumboFlag: "test.jumbo",
   bounds: [{ "x" : 1 }, { "x" : 2 }]
} )

Upon success, the command returns "ok": 1 in its output:

{
   "ok" : 1,
   "operationTime" : Timestamp(1580190080, 5),
   "$clusterTime" : {
      "clusterTime" : Timestamp(1580190080, 5),
      "signature" : {
         "hash" : BinData(0,"0cYT49s72MHUYV1F2WpoEwlyeVs="),
         "keyId" : NumberLong("6786859092951433239")
      }
   }
}

The following clearJumboFlag command specifies the find field to find the chunk that contains the shard key { "x" : 2 } :

db.adminCommand( {
   clearJumboFlag: "test.jumbo",
   find: { "x" : 2 }
} )

Upon success, the command returns "ok": 1 in its output:

{
   "ok" : 1,
   "operationTime" : Timestamp(1580191819, 5),
   "$clusterTime" : {
      "clusterTime" : Timestamp(1580191819, 5),
      "signature" : {
         "hash" : BinData(0,"N6x6drN7HUq5MR5ezUJns1rfeqY="),
         "keyId" : NumberLong("6786859092951433239")
      }
   }
}

To verify the operation, run sh.status() again. The jumbo flag should no longer appear in its output.

... // Content omitted for brevity

test.jumbo
         shard key: { "x" : 1 }
         unique: false
         balancing: true
         chunks:
                 shardA   2
                 shardB   2
         { "x" : { "$minKey" : 1 } } -->> { "x" : 1 } on : shardB Timestamp(3, 0)
{ "x" : 1 } -->> { "x" : 2 } on : shardA Timestamp(7, 0){ "x" : 2 } -->> { "x" : 3 } on : shardA Timestamp(8, 0)         { "x" : 3 } -->> { "x" : { "$maxKey" : 1 } } on : shardB Timestamp(6, 0)

Clear Jumbo Flag for a Chunk (Hashed Shard Key)

The sh.status() includes the following sh.status.databases.<collection>.chunk-details for the test.jumboHashed collection. The collection uses a hashed shard key.

... // Content omitted for brevity

test.jumboHashed
         shard key: { "x" : "hashed" }
         unique: false
         balancing: true
         chunks:
                 shardA   2
                 shardB   2
         { "x" : { "$minKey" : 1 } } -->> { "x" : NumberLong(0) } on : shardA Timestamp(1, 0)
         { "x" : NumberLong(0) } -->> { "x" : NumberLong("848411777775835583") } on : shardA Timestamp(4, 0)
{ "x" : NumberLong("848411777775835583") } -->> { "x" : NumberLong("5902408780260971510") } on : shardB Timestamp(4, 1) jumbo         { "x" : NumberLong("5902408780260971510") } -->> { "x" : { "$maxKey" : 1 } } on : shardB Timestamp(2, 2)

To clear the jumbo flag for a chunk if the collection uses a hashed shard key, use clearJumboFlag with the bounds field:

db.adminCommand( {
   clearJumboFlag: "test.jumboHashed",
   bounds: [{ "x" : NumberLong("848411777775835583") }, { "x" : NumberLong("5902408780260971510") }]
} )

Upon success, the command returns "ok": 1 in its output:

{
   "ok" : 1,
   "operationTime" : Timestamp(1580194290, 5),
   "$clusterTime" : {
      "clusterTime" : Timestamp(1580194290, 5),
      "signature" : {
         "hash" : BinData(0,"nWCqOYVrab7NEGHWoo2NYENqHR4="),
         "keyId" : NumberLong("6786875525496307742")
      }
   }
}

To verify the operation, run sh.status() again. The jumbo flag should no longer appear in its output.

... // Content omitted for brevity

test.jumboHashed
        shard key: { "x" : "hashed" }
        unique: false
        balancing: true
        chunks:
                shardA    2
                shardB    2
        { "x" : { "$minKey" : 1 } } -->> { "x" : NumberLong(0) } on : shardA Timestamp(1, 0)
        { "x" : NumberLong(0) } -->> { "x" : NumberLong("848411777775835583") } on : shardA Timestamp(4, 0)
{ "x" : NumberLong("848411777775835583") } -->> { "x" : NumberLong("5902408780260971510") } on : shardB Timestamp(5, 0)        { "x" : NumberLong("5902408780260971510") } -->> { "x" : { "$maxKey" : 1 } } on : shardB Timestamp(2, 2)

See also参阅

Clear jumbo Flag