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reshardCollection Event

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Summary摘要

reshardCollection

New in version 6.0. 6.0版新增。

A reshardCollection event occurs when the shard key for a collection and the distribution of your data is changed.当集合的分片键和数据的分布发生更改时，将发生reshardCollection事件。

Description描述

Field字段Type类型Description描述
_idDocumentA BSON object which serves as an identifier for the change stream event. BSON对象，用作更改流事件的标识符。This value is used as the resumeToken for the resumeAfter parameter when resuming a change stream. 恢复更改流时，此值用作resumeAfter参数的resumeToken。The _id object has the following form: _id对象具有以下形式：
{
   "_data" : <BinData|hex string>
}
The _data type depends on the MongoDB versions and, in some cases, the feature compatibility version (fCV) at the time of the change stream's opening or resumption. _data类型取决于MongoDB版本，在某些情况下，还取决于更改流打开或恢复时的功能兼容性版本（fCV）。See Resume Tokens for the full list of _data types.请参阅恢复令牌以获取_data类型的完整列表。
For an example of resuming a change stream by resumeToken, see Resume a Change Stream. 有关通过resumeToken恢复更改流的示例，请参阅恢复更改流。
clusterTimeTimestampThe timestamp from the oplog entry associated with the event.与事件相关联的oplog条目中的时间戳。
Change stream event notifications associated with a multi-document transaction all have the same clusterTime value: the time when the transaction was committed.与多文档事务关联的更改流事件通知都具有相同的clusterTime值：事务提交的时间。
On sharded clusters, events with the same clusterTime may not all relate to the same transaction. Some events don't relate to a transaction at all.在分片集群上，具有相同clusterTime的事件可能并不都与同一事务相关。有些事件根本与事务无关。
To identify events for a single transaction, you can use the combination of lsid and txnNumber in the change stream event document. 要识别单个事务的事件，可以在更改流事件文档中使用lsid和txnNumber的组合。
New in version 4.0. 4.0版新增。
collectionUUIDUUIDUUID identifying the collection where the change occurred. 标识了发生更改的集合。
New in version 6.0. 6.0版新增。
nsDocumentThe namespace (database and or collection) affected by the event. 受事件影响的命名空间（数据库和/或集合）。
ns.collStringThe name of the collection where the event occurred. 发生事件的集合的名称。
ns.dbStringThe name of the database where the event occurred. 发生事件的数据库的名称。
operationDescriptionDocumentAdditional information on the change operation.有关更改操作的其他信息。
This document and its subfields only appears when the change stream uses expanded events. 只有当变更流使用展开的事件时，才会显示此文档及其子字段。
New in version 6.0. 6.0版新增。
operationDescription.
reshardUUID		UUIDUUID that identifies the resharding operation. 标识重新分拣操作的UUID。
New in version 6.1. 6.1版新增。
operationDescription. | shardKeyDocumentThe shard key for the collection where the change occurred. 发生更改的集合的分片键。
New in version 6.0. 6.0版新增。
operationDescription. | oldShardKeyDocumentThe shard key for the collection that changed. 更改的集合的分片键。
New in version 6.1. 6.1版新增。
operationDescription. | uniqueBooleanThis has a value of true if the collection was sharded with a unique shard key. 如果使用唯一的分片键对集合进行分片，则该值为true。
New in version 6.0. 6.0版新增。
operationDescription. | numInitialChunksNumberLongNumber of chunks created on each shard during a shardCollection operation. shardCollection操作期间在每个分片上创建的块数。
New in version 6.0. 6.0版新增。
operationDescription.
collation		DocumentCollation document used for the shard key index. 用于分片键索引的排序规则文档。
New in version 6.1. 6.1版新增。
operationDescription.
zones		ArrayThe zones added for the new shard key. 为新分片键添加的区域。
New in version 6.1. 6.1版新增。

Example实例

The following example shows a reshardCollection event:以下示例显示了一个reshardCollection事件：

{
   "_id": { <ResumeToken> },
   "operationType": "reshardCollection",
   "collectionUUID": 0,
   "ns": {"db": "reshard_collection_event", "coll": "coll"},
   "operationDescription": {
     "reshardUUID": 0,
     "shardKey": {"newKey": 1},
     "oldShardKey": {"_id": 1},
     "unique": false,
     "numInitialChunks": NumberLong(1),
     "collation": {"locale": "simple"},
     "zones": [
         {"zone": "zone1", "min": {"newKey": {"$minKey": 1}}, "max": {"newKey": {"$maxKey": 1}}}
     ]
   }
}