setIndexCommitQuorum (database command数据库命令)

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

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

db.runCommand(
   {
     setIndexCommitQuorum: <string>,
     indexNames: [ <document> ],
     commitQuorum: <int> | <string>,
     comment: <any>
   }
)

Command Fields命令字段

The command takes the following fields:该命令包含以下字段：

Behavior行为

Index creation is a multistage process. The index creation process uses the commit quorum to minimize replication lag on secondary nodes.索引创建是一个多阶段的过程。索引创建过程使用commit quorum（提交仲裁）来最小化辅助节点上的复制延迟。

When a secondary node receives a commitIndexBuild oplog entry, the node stops further oplog applications until the local index build can be committed. Index builds can take anywhere from moments to days to complete, so the replication lag can be significant if the secondary node builds more slowly than the primary.当辅助节点收到commitIndexBuild oplog条目时，该节点会停止进一步的oplog应用程序，直到可以提交本地索引构建。索引构建可能需要几分钟到几天的时间才能完成，因此如果辅助节点的构建速度比主节点慢，复制延迟可能会很大。

To manage the replication lag, the commit quorum delays committing the index build on the primary node until a minimum number of secondaries are also ready to commit the index build.为了管理复制延迟，提交仲裁会延迟在主节点上提交索引构建，直到最小数量的辅助节点也准备好提交索引构建。

The commit quorum does not guarantee that indexes on secondaries are ready for use when the command completes. To ensure that a specific number of secondaries are ready for use, set an appropriate write concern.提交仲裁不保证在命令完成时辅助服务器上的索引已准备好使用。为确保有特定数量的中学可供使用，请设置适当的写入关注。

If a secondary node that is not included in the commit quorum receives a commitIndexBuild oplog entry, the node may block replication until its index build is complete.如果未包含在提交仲裁中的辅助节点收到commitIndexBuild oplog条目，则该节点可能会阻止复制，直到其索引构建完成。

Issuing setIndexCommitQuorum has no effect on index builds started with commitQuorum of 0.发出setIndexCommitQuorum对以commitQuorum为0启动的索引构建没有影响。

Examples示例

Index builds on a replica set or sharded cluster build simultaneously across all data-bearing replica set members. For sharded clusters, the index build occurs only on shards containing data for the collection being indexed. 索引基于副本集构建，或在所有承载数据的副本集成员之间同时构建分片集群。对于分片集群，索引构建仅发生在包含被索引集合的数据的分片上。The primary requires a minimum number of data-bearing voting members (i.e commit quorum), including itself, that must complete the build before marking the index as ready for use. 初选需要最少数量的数据承载voting成员（即提交法定人数），包括其本身，在将索引标记为可供使用之前，必须完成构建。See Index Builds in Replicated Environments for more information.有关更多信息，请参阅复制环境中的索引构建。

The following operation starts an index build of two indexes:以下操作启动两个索引的索引构建：

db.getSiblingDB("examples").invoices.createIndexes(
  [
    { "invoices" : 1 },
    { "fulfillmentStatus" : 1 }
  ]
)

By default, index builds use "votingMembers" commit quorum, or all data-bearing voting replica set members. The following operation modifies the index build commit quorum to "majority", or a simple majority of data-bearing voting members:.默认情况下，索引构建使用"votingMembers"提交仲裁，或所有承载数据的投票副本集成员。以下操作将索引构建提交法定人数修改为"majority"，或简单多数数据承载投票成员：。

db.getSiblingDB("examples").runCommand(
  {
    "setIndexCommitQuorum" : "invoices",
    "indexNames" : ["invoices_1", "fullfillmentStatus_1"],
    "commitQuorum" : "majority"
  }
)

• The indexes specified to indexNames must be the entire set of in-progress builds associated to a given index builder, i.e. the createIndexes() operation.为indexNames指定的索引必须是与给定索引生成器关联的整个正在进行的构建集，即createIndexes()操作。
• The indexNames field specifies the names of the indexes. Since the indexes were created without an explicit name, MongoDB generated an index name by concatenating the names of the indexed fields and the sort order.indexNames字段指定索引的名称。由于索引是在没有显式名称的情况下创建的，MongoDB通过连接索引字段的名称和排序顺序来生成索引名称。