Database Manual / Reference / Database Commands / Sharding

clearJumboFlag (database command数据库命令)

Definition定义

clearJumboFlag
Clears the jumbo flag for a chunk. To use the command, issue the clearJumboFlag command on a mongos instance.清除大块的jumbo标志。要使用该命令，请在mongos实例上发出clearJumboFlag命令。

Compatibility兼容性

This command is available in deployments hosted in the following environments:此命令在以下环境中托管的部署中可用：

  • MongoDB Atlas: The fully managed service for MongoDB deployments in the cloud：云中MongoDB部署的完全托管服务
  • MongoDB Enterprise: The subscription-based, self-managed version of MongoDB：MongoDB的基于订阅的自我管理版本
  • MongoDB Community: The source-available, free-to-use, and self-managed version of MongoDB：MongoDB的源代码可用、免费使用和自我管理版本

Syntax语法

Th command has the following syntax:Th命令具有以下语法：

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命令字段

The clearJumboFlag command takes the following fields as arguments:clearJumboFlag命令接受以下字段作为参数：

Field字段Type类型Description描述
clearJumboFlagstring字符串

The namespace of the sharded collection with the jumbo chunk(s).带有巨型块的分片集合的命名空间。

Specify the collection's full namespace, including the database name (i.e. "<database>.<collection>")指定集合的完整命名空间，包括数据库名称（即"<database>.<collection>"）

boundsarray数组

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:特定块的确切边界。数组必须由两个文档组成，这两个文档指定要移动的块的下分片键值和上分片键值：

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

finddocument文档

A specific shard key and its value contained in the jumbo chunk.一个特定的分片键及其值包含在巨型块中。

{ <shardKey> : <value> }

Access Control访问控制

On systems running with authorization, the user must have the clearJumboFlag privilege actions on the { db: "", collection: "" } resource.在authorization运行的系统上，用户必须对{ db: "", collection: "" } 资源具有clearJumboFlag权限操作。

The built-in role clusterManager provides the appropriate privileges.内置的角色clusterManager提供了适当的权限。

Example示例

Clear Jumbo Flag for a Chunk (Range-Based Shard Key)清除块的巨型标志（基于范围的分片键）

The sh.status() includes the following sh.status.databases.<collection>.chunk-details for the test.jumbo collection.sh.status()包括以下test.jumbo集合的sh.status.databases.<collection>.chunk-details。

... // 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:以下clearJumboFlag命令指定了{ "x" : 1 } -->> { "x" : 2 }块的bounds：

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

Upon success, the command returns "ok": 1 in its output:成功后，命令在其输出中返回"ok": 1：

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

The following clearJumboFlag command specifies the find field to find the chunk that contains the shard key { "x" : 2 } :以下clearJumboFlag命令指定find字段以查找包含分片键{ "x" : 2 }的块：

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

Upon success, the command returns "ok": 1 in its output:成功后，命令在其输出中返回"ok": 1：

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

To verify the operation, run sh.status() again. The jumbo flag should no longer appear in its output.要验证操作，请再次运行sh.status()。jumbo标志不应再出现在其输出中。

... // 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)清除块的巨型标志（哈希分片键）

The sh.status() includes the following sh.status.databases.<collection>.chunk-details for the test.jumboHashed collection. sh.status()包括以下test.jumboHashed集合sh.status.databases.<collection>.chunk-details。The collection uses a hashed shard key.该集合使用哈希分片键。

... // Content omitted for brevity

test.jumboHashed
         shard key: { "x" : "hashed" }
         unique: false
         balancing: true
         chunks:
                  shardA   2
                  shardB   2
         { "x" : { "$minKey" : 1 } } -->> { "x" : Long(0) } on : shardA Timestamp(1, 0)
         { "x" : Long(0) } -->> { "x" : Long("848411777775835583") } on : shardA Timestamp(4, 0)
         { "x" : Long("848411777775835583") } -->> { "x" : Long("5902408780260971510") } on : shardB Timestamp(4, 1) jumbo
         { "x" : Long("5902408780260971510") } -->> { "x" : { "$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:如果集合使用哈希分片键，要清除块的jumbo标志，请在bounds字段中使用clearJumboFlag：

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

Upon success, the command returns "ok": 1 in its output:成功后，命令在其输出中返回"ok": 1：

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

To verify the operation, run sh.status() again. The jumbo flag should no longer appear in its output.要验证操作，请再次运行sh.status()。jumbo标志不应再出现在其输出中。

... // Content omitted for brevity

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

Tip

Clear jumbo Flag