- Storage >
- Storage Engines >
- WiredTiger Storage Engine >
- Change Sharded Cluster to WiredTiger
Change Sharded Cluster to WiredTiger¶
Starting in version 3.2, WiredTiger is the default storage engine for MongoDB. Use this tutorial to update your 3.2 sharded clusters to use WiredTiger.
To convert a 3.0 sharded cluster that uses MMAPv1, see the MongoDB 3.0 manual.
Considerations¶
Downtime¶
This procedure may involve downtime, especially if one or more of your shards is a standalone. If you change the host or port of any shard, you must update the shard configuration as well.
MongoDB 3.0 or Greater¶
Change Shards to WiredTiger¶
Note
A sharded cluster can have mixed storage engines for its individual shards.
To change the storage engine for the shards to WiredTiger, refer to the appropriate procedure for each shard:
- If the shard is a standalone, see Change Standalone to WiredTiger.
- If the shard is a replica set, see Change Replica Set to WiredTiger.
Change Config Servers to WiredTiger¶
CSRS¶
Starting in MongoDB 3.2, config servers can be deployed as replica sets. If the config servers are deployed as a replica set (CSRS), the config servers already use WiredTiger.
Mirrored mongod
Instances¶
If the config servers are deployed as 3 mirrored mongod
instances, see Change Config Servers to WiredTiger to
change the storage engines of these config servers.
You may safely continue to use MMAPv1 for the config servers even if one or more shards in the sharded cluster are using the WiredTiger storage engine. If you do choose to update the config servers to use WiredTiger, you must update all three.