Database Manual / Change Streams / Change Events

invalidate Event

Summary

invalidate

An invalidate event occurs when an operation renders the change stream invalid. For example, a change stream opened on a collection that was later dropped or renamed would cause an invalidate event.

Description

FieldTypeDescription

_id

Document

A BSON object which serves as an identifier for the change stream event. This value is used as the resumeToken for the resumeAfter parameter when resuming a change stream. The _id object has the following form:

{
   "_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. See Resume Tokens for the full list of _data types.

For an example of resuming a change stream by resumeToken, see Resume a Change Stream.

clusterTime

Timestamp

clusterTime is the timestamp from the oplog entry associated with the event.

Due to oplog size limits, multi-document transactions may create multiple oplog entries. In a transaction, change stream events staged in a given oplog entry share the same clusterTime.

Events with the same clusterTime may not all relate to the same transaction. Some events don't relate to a transaction at all. Starting in MongoDB 8.0, this may be true for events on any deployment. In previous versions, this behavior was possible only for events on a sharded cluster.

To identify events for a single transaction, you can use the combination of lsid and txnNumber in the change stream event document.

Changed in version 8.0.

operationType

string

The type of operation that the change notification reports.

Returns a value of invalidate for these change events.

wallTime

ISODate

The server date and time of the database operation. wallTime differs from clusterTime in that clusterTime is a timestamp taken from the oplog entry associated with the database operation event.

New in version 6.0.

Example

The following example illustrates an invalidate event:

{
   "_id": { <Resume Token> },
   "operationType": "invalidate",
   "clusterTime": <Timestamp>,
   "wallTime": <ISODate>
}

Change streams opened on collections raise an invalidate event when a drop, rename, or dropDatabase operation occurs that affects the watched collection.

Change streams opened on databases raise an invalidate event when a dropDatabase event occurs that affects the watched database.

invalidate events close the change stream cursor.

You cannot use resumeAfter to resume a change stream after an invalidate event (for example, a collection drop or rename) closes the stream. Instead, you can use startAfter to start a new change stream after an invalidate event.