Configure Additional Options¶
You can configure the following mongod runtime options
on M10+ paid tier clusters.
To view these settings, open the More Configuration Options under Additional Settings in the cluster form.
Set Oplog Size¶
Modify the oplog size of the cluster.
For sharded cluster deployments, this modifies the oplog size of each shard in the cluster.
This option corresponds to modifying the
replication.oplogSizeMB configuration file option for each
mongod in the cluster.
Specify your desired Oplog Size in megabytes in the input box.
If your change would reduce free disk space to below 25 percent, Atlas displays an error. Atlas doesn't change the oplog size until you choose a value above that threshold.
To check the oplog size:
- Connect to your cluster via the
mongoshell. - Authenticate as a user with the
Atlas adminrole. - Run the
rs.printReplicationInfo()method.
Atlas displays the current oplog size and time.
Reducing the size of the oplog requires removing data from the oplog. Atlas cannot access or restore any oplog entries removed as a result of oplog reduction. Consider the ramifications of this data loss before reducing the oplog.
Disk Space Considerations¶
Do not reduce the size of the oplog as a means of increasing available
disk space. Only the oplog collection (local.oplog.rs) can reclaim
the space saved by reducing the oplog size. Other collections do not
benefit from reducing oplog storage.
Enforce Index Key Limit¶
Enable or disable enforcement of the 1024-byte index key limit. Documents can only be updated or inserted if, for all indexed fields on the target collection, the corresponding index entries do not exceed 1024 bytes.
If disabled, mongod writes documents that breach the
limit but does not index them. This option corresponds to
modifying the
failIndexKeyTooLong
parameter via the setParameter command for each
mongod in the cluster.
failIndexKeyTooLong
was deprecated in MongoDB version 4.2 and is removed in MongoDB 4.4
and later.
Allow Server-Side JavaScript¶
Enable or disable execution of operations that perform server-side execution of JavaScript.
- If your cluster runs a MongoDB version less than 4.4, this option
corresponds to modifying the
security.javascriptEnabledconfiguration file option for eachmongodin the cluster. - If your cluster runs MongoDB version 4.4 or greater, this option
corresponds to modifying the
security.javascriptEnabledconfiguration file option for eachmongodandmongosin the cluster.
In MongoDB version 4.4 and later,
security.javascriptEnabled applies to
mongos' as well.
Set Minimum TLS Protocol Version¶
Sets the minimum TLS version the cluster accepts for incoming
connections. This option corresponds to configuring the
net.ssl.disabledProtocols configuration file option
for each mongod in the cluster.
For users considering this option as a method for enabling the deprecated Transport Layer Security (TLS) 1.0 protocol version, please read What versions of TLS does Atlas support? before proceeding. Atlas deprecation of TLS 1.0 improves your security of data-in-transit and aligns with industry best practices. Enabling TLS 1.0 for any Atlas cluster carries security risks. Consider enabling TLS 1.0 only for as long as required to update your application stack to support TLS 1.1 or later.
Require Indexes for All Queries¶
Enable or disable the execution of queries that require a collection
scan to return results. This option corresponds to modifying the
notablescan parameter via the
setParameter command for each mongod in
the cluster.
Considerations¶
Atlas dynamically modifies the Oplog Size for replica sets and sharded clusters. However, for the Minimum TLS Protocol Version and Allow Server-Side JavaScript settings, it performs a rolling restart of the shard members and the config server replica set. To learn more about how Atlas supports high availability during maintenance operations, see How does MongoDB Atlas deliver high availability?.