Viewing shard-cluster participants

Run the db.runCommand MongoDB shell command with listShards syntax to list the Enterprise Replication group names, hosts, and port numbers of all shard servers in a shard cluster.

Procedure

Run the mongo command.
The command starts the MongoDB shell.
Run the listShards command:
```
db.runCommand({listShards:1})
```

Results

The listShards command produces output in the following structure:

{
        "serverUsed" : "server_host/IP_address",
        "shards" : [
                {
                        "_id" : "ER_group_name_1",
                        "host" : "host_1:port_1"
                },
                {
                        "_id" : "ER_group_name_2",
                        "host" : "host_2:port_2"
                },
                {
                        "_id" : "ER_group_name_x",
                        "host" : "host_x:port_x"
                }
        ],
        "ok" : 1
}

ER_group_name: The Enterprise Replication group name of a shard server.
host: The host for a shard-cluster participant. The host can be a localhost name or a full domain name.
IP_address: The IP address of the database server that the listener is connected to.
port: The port number that a shard-cluster participant uses to communicate with other shard-cluster participants.
server_host: The host for the database server that the listener is connected to. The host can be a localhost name or a full domain name.

Example

For this example, you have a shard cluster defined by the following command:

prompt> db.runCommand({"addShard":["myhost1.ibm.com:9201",
   "myhost2.ibm.com:9202","myhost3.ibm.com:9203",
   "myhost4.ibm.com:9204","myhost5.ibm.com:9205"]})

The following example output is shown when the listShards command is run in the MongoDB shell, and the listener is connected to the database server at myhost1.ibm.com.

Figure 1. listShards command output for a shard cluster

{
        "serverUsed" : "myhost1.ibm.com/192.0.2.0:9200",
        "shards" : [
                {
                        "_id" : "g_myserver1",
                        "host" : "myhost1.ibm.com:9200"
                },
                {
                        "_id" : "g_myserver2",
                        "host" : "myhost2.ibm.com:9202"
                },
                {
                        "_id" : "g_myserver3",
                        "host" : "myhost3.ibm.com:9203"
                }
                {
                        "_id" : "g_myserver4",
                        "host" : "myhost4.ibm.com:9204"
                }
                {
                        "_id" : "g_myserver5",
                        "host" : "myhost5.ibm.com:9205"
                }
        ],
        "ok" : 1
}