Upgrade to the Latest Revision of MongoDB¶

On this page

Before Upgrading
Upgrade Procedure
Upgrade a MongoDB Instance
Replace the Existing Binaries
Upgrade Replica Sets
Upgrade Sharded Clusters

MongoDB versioning have the form X.Y.Z where Z refers to the revision/patch number. Revisions provide security patches, bug fixes, and new or changed features that generally do not contain any backward breaking changes. Always upgrade to the latest revision in your release series.

For more information on versioning, see MongoDB Versioning.

Before Upgrading¶

Backup¶

Ensure you have an up-to-date backup of your data set. See MongoDB Backup Methods.

Compatibility Considerations¶

Consult the following documents for any special considerations or compatibility issues specific to your MongoDB release:
- The release notes, located at Release Notes.
- The documentation for your driver. See Drivers and Driver Compatibility pages for more information.

Important

Starting in MongODB 4.2, MongoDB removes support for Ubuntu 16.04 PPCLE.
Starting in MongoDB 3.6.13, MongoDB 3.6-series removes support for Ubuntu 16.04 PPCLE.
Starting in MongoDB 3.4.21, MongoDB 3.4-series removes support for Ubuntu 16.04 PPCLE.

Maintenance Window¶

If your installation includes replica sets, plan the upgrade during a predefined maintenance window.

Change Streams¶

Starting in MongoDB 4.0.7, change streams use a version 1 v1 resume tokens. MongoDB versions earlier than 4.0.7 use v0 resume tokens.

When upgrading from MongoDB 4.0.6 or earlier to MongoDB 4.0.7 or later, a client may try to resume change streams using the new v1 resume token when connected to a member that has not been updated (i.e. only accepts v0 or BinData token) and fail. In such cases, the client must wait for the upgrade to complete before resuming change streams.

3-Member PSA Architecture¶

Starting in MongoDB 3.6, MongoDB enables support for "majority" read concern by default.

You can disable read concern "majority" to prevent the storage cache pressure from immobilizing a deployment with a primary-secondary-arbiter (PSA) architecture. However,

Disabling "majority" read concern disables support for Change Streams for MongoDB 4.0 and earlier. For MongoDB 4.2+, disabling read concern "majority" has no effect on change streams availability.
Disabling "majority" read concern prevents collMod commands which modify an index from rolling back. If such an operation needs to be rolled back, you must resync the affected nodes with the primary node.
Disabling "majority" read concern affects support for transactions on sharded clusters. Specifically:
- A transaction cannot use read concern "snapshot" if the transaction involves a shard that has disabled read concern “majority”.
- A transaction that writes to multiple shards errors if any of the transaction’s read or write operations involves a shard that has disabled read concern "majority".
However, it does not affect transactions on replica sets. For transactions on replica sets, you can specify read concern "majority" (or "snapshot" or "local" ) for multi-document transactions even if read concern "majority" is disabled.

For more information, see Disable Read Concern Majority.

Staging Environment Check¶

Before you upgrade a production environment, use the procedures in this document to upgrade a staging environment that reproduces your production environment, to ensure that your production configuration is compatible with all changes.

Upgrade Procedure¶

Important

Always backup all of your data before upgrading MongoDB.

Upgrade each mongod and mongos binary separately, using the procedure described here. When upgrading a binary, use the procedure Upgrade a MongoDB Instance.

Follow this upgrade procedure:

For deployments that use authentication, first upgrade all of your MongoDB drivers. To upgrade, see the documentation for your driver as well as the Driver Compatibility page.
Upgrade sharded clusters, as described in Upgrade Sharded Clusters.
Upgrade any standalone instances. See Upgrade a MongoDB Instance.
Upgrade any replica sets that are not part of a sharded cluster, as described in Upgrade Replica Sets.

Upgrade a MongoDB Instance¶

To upgrade a mongod or mongos instance, use one of the following approaches:

Upgrade the instance using the operating system’s package management tool and the official MongoDB packages. This is the preferred approach. See Install MongoDB.
Upgrade the instance by replacing the existing binaries with new binaries. See Replace the Existing Binaries.

Replace the Existing Binaries¶

Important

Always backup all of your data before upgrading MongoDB.

This section describes how to upgrade MongoDB by replacing the existing binaries. The preferred approach to an upgrade is to use the operating system’s package management tool and the official MongoDB packages, as described in Install MongoDB.

To upgrade a mongod or mongos instance by replacing the existing binaries:

Download the binaries for the latest MongoDB revision from the MongoDB Download Page and store the binaries in a temporary location. The binaries download as compressed files that uncompress to the directory structure used by the MongoDB installation.
Shutdown the instance.
Replace the existing MongoDB binaries with the downloaded binaries.
Restart the instance.

Upgrade Replica Sets¶

To upgrade a replica set, upgrade each member individually, starting with the secondaries and finishing with the primary. Plan the upgrade during a predefined maintenance window.

Note

Starting in MongoDB 4.0.7, change streams use a version 1 v1 resume tokens. MongoDB versions earlier than 4.0.7 use v0 resume tokens or BinData resume tokens.

When upgrading from MongoDB 4.0.0-4.0.6 to MongoDB 4.0.7 or later, a client may try to resume change streams using the new v1 resume token when connected to a member that has not been updated (i.e. only accepts v0 token or BinData) and fail. In such cases, the client must wait for the upgrade to complete before resuming change streams.

Upgrade Secondaries¶

Upgrade each secondary separately as follows:

Upgrade the secondary’s mongod binary by following the instructions in Upgrade a MongoDB Instance.
After upgrading a secondary, wait for the secondary to recover to the SECONDARY state before upgrading the next instance. To check the member’s state, issue rs.status() in the mongo shell.

The secondary may briefly go into STARTUP2 or RECOVERING. This is normal. Make sure to wait for the secondary to fully recover to SECONDARY before you continue the upgrade.

Upgrade the Primary¶

Step down the primary to initiate the normal failover procedure. Using one of the following:
- The rs.stepDown() helper in the mongo shell.
- The replSetStepDown database command.
During failover, the set cannot accept writes. Typically this takes 10-20 seconds. Plan the upgrade during a predefined maintenance window.

Note

Stepping down the primary is preferable to directly shutting down the primary. Stepping down expedites the failover procedure.
Once the primary has stepped down, call the rs.status() method from the mongo shell until you see that another member has assumed the PRIMARY state.
Shut down the original primary and upgrade its instance by following the instructions in Upgrade a MongoDB Instance.

Upgrade Sharded Clusters¶

Changed in version 3.4: The procedure applies to 4.4. To make revision upgrades for other versions of MongoDB sharded clusters, refer to the appropriate version of the manual.

Note

Starting in MongoDB 4.0.7, change streams use a version 1 v1 resume tokens. MongoDB versions earlier than 4.0.7 use v0 resume tokens or BinData resume tokens.

When upgrading from MongoDB 4.0.6 or earlier to 4.0.7 or later, the members of the sharded clusters will continue to produce v0 or BinData resume tokens until the mongos instance(s) are updated. Upgraded mongos instances will begin producing v1 change stream resume tokens. These tokens cannot be used to resume a stream on a mongos that has not yet been upgraded to 4.0.7 or later.

To upgrade a 4.4 sharded cluster:

Disable the cluster’s balancer as described in Disable the Balancer.
Upgrade the config servers.

To upgrade the config server replica set, use the procedures in Upgrade Replica Sets.
Upgrade each shard.
- If a shard is a replica set, upgrade the shard using the procedure titled Upgrade Replica Sets.
- If a shard is a standalone instance, upgrade the shard using the procedure titled Upgrade a MongoDB Instance.
Once the config servers and the shards have been upgraded, upgrade each mongos instance by following the instructions in Upgrade a MongoDB Instance. You can upgrade the mongos instances in any order.
Re-enable the balancer, as described in Enable the Balancer.

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