boost::mqtt5::mqtt_client::brokers

Assign a list of Brokers that the Client will attempt to connect to.

boost::mqtt5::mqtt_client&
brokers(
    std::string hosts,
    uint16_t default_port = 1883);

The Client will cycle through the list of hosts, attempting to establish a connection with each until it successfully establishes a connection.

Name	Description
`hosts`	List of Broker addresses and ports. Address and ports are separated with a colon `:` while pairs of addresses and ports are separated with a comma `,`.
`default_port`	The default port to connect to in case the port is not explicitly specified in the `hosts` list.

This function has no effect while the Client is running. Call it before async_run, or after cancel or async_disconnect and before invoking async_run again.

Some valid hosts string:

std::string valid_hosts_1 = "broker1:1883, broker2, broker3:1883";
std::string valid_hosts_2 = "broker1";