NBWSS uses the following rules to establish a connection to an endpoint:

• If no active connections exist to an endpoint in a server group, NetBackup attempts to connect to the endpoint that has the highest priority.

• If unable to connect to an endpoint within a server group (the server is down), NetBackup attempts to connect to the endpoint that has the next highest priority in that server group.

Note these additional rules and limitations:

• At most one connection can exist per endpoint at a time.

• At most one connection can exist per server group at a time.

• NBWSS does not automatically close an existing connection when a higher priority connection comes online. For example, assume that server group sg1 has two endpoints (ep1 and ep2) with priorities 1 and 2, respectively. If NBWSS is currently connected to ep2 (priority 2) and ep1 (priority 1) comes online, NBWSS does not automatically connect to ep1. The cloud application must close the connection to ep2 before NBWSS attempts to connect to ep1.

• A connection process runs on a timer that responds to endpoint connection changes (such as for connecting to new endpoints or disconnecting from removed endpoints). The default period for this task is 60 seconds. As a result, it may be up to 1 minute before endpoint changes take effect.

  You can use the connectionInfo.period property to configure this task.

  See Configuring the properties of the NetBackup WebSocket Service (NBWSS).

• When the NetBackup Web Management Console service is restarted, the NetBackup web server takes a few minutes to start. As a result, it takes a few minutes for currently configured endpoints to appear in the NetBackup Administration Console. The endpoints appear under Media and Device Management > Credentials > WebSocket Servers.

• An established connection does not have a time limit; the connection can exist indefinitely. In some cases the connection may have to be re-established, such as when the token that NetBackup sends to the cloud application has expired. In that case, the NetBackup credentials for the endpoint must be re-added with a new, valid token. The connection is re-established the next time the connection process runs (determined by the connectionInfo.period property).

• The maximum incoming packet size that is allowed on the NetBackup WebSocket channel is 2 MB. If the NetBackup WebSocket server receives a packet that is larger than 2MB, the connection is dropped. In the next refresh of connections (by default, 60 seconds later), NBWSS attempts to reconnect with the remote endpoint.