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Oplog Access

On this page

  • Add a User with Oplog Access
  • Access the Oplog

Important

Feature unavailable in Serverless Instances

Serverless instances don't support this feature at this time. To learn more, see Serverless Instance Limitations.

The oplog, a special capped collection, records operations that modify the data stored in your databases.

Note

You must precede a $regex query on an oplog in an M0 free cluster or M2/M5 shared cluster with a caret (^). Otherwise, the following error occurs:

MongoServerError: Oplog ns RegEx queries must begin with ^

To access the oplog, a database user must have read access on the local database. To create a user with read access on local:

1
  1. If it's not already displayed, select the organization that contains your project from the Organizations menu in the navigation bar.

  2. If it's not already displayed, select your project from the Projects menu in the navigation bar.

  3. In the left-hand menu, click Database Access under the Security heading.

2
  1. It it's not already displayed, click the Database Users tab.

  2. Click Add New Database User and enter a user name such as oploguser.

  3. Click Grant Specific Privileges and select the read role and the local database. This restricts the user to read operations on the local database.

  4. Enter a password and click Add User.

  1. Connect to your cluster with the mongosh, using the credentials of the new database user with access to the local database.

  2. Switch to the local database.

    > use local
  3. The oplog collection is named oplog.rs. Database write operations are recorded in date order, with a timestamp field and a wall clock field.

    The timestamp field contains an integer with seconds since epoch.

Note

← Commands Available Only in M0, M2, and M5 Clusters and Serverless Instances