DB instance specifications are listed in the following table.

The DB instance specifications depend on service requirements.

You can change the maximum number of connections of a DB instance by modifying the net.maxIncomingConnections parameter. For details about how to change the parameter value, see Modifying a Parameter Template.

Cluster

For details about the cluster instance specifications, see Table 1 and Table 2.

**Table 1** config specifications
CPU Type	vCPUs	Memory (GB)	Default Maximum Number of Connections
x86	2	4	600
Kunpeng	2	4	600

**Table 2** shard and dds mongos specifications
vCPUs	Memory (GB)	Default Maximum Number of Connections
1	4	400
2	8	400
4	16	1000
8	32	4000
16	64	8000

Replica Set

The specifications supported by a replica set are the same as those supported by shard and dds mongos. For details, see Table 2.

Single Node

The specifications supported by a single node are the same as those supported by shard and dds mongos. For details, see Table 2.

DB Instance Specifications

Cluster

Replica Set

Single Node