Two Operations Sentinel servers can be configured for use in a resilient monitoring environment. Each client program must establish a connection to the secondary server to use this feature. All events generated by the client are normally sent to the primary server. If the client has registered for event callbacks, only events from the primary server are reported to the client in a resilient server environment.

If a client loses connection with the primary server, all events generated by the client are sent to the secondary server. In addition, the client callbacks begin receiving events from the secondary server. When the primary server is once again available, all events are sent to the primary server and the client callbacks are again received only from the primary Operations Sentinel server.

Specifying a Secondary Server

Set the environment variable SPO_EVENT_SECONDARY to specify the location of the secondary server before a client is started. As the value of this variable, use the name or IP address of the secondary server (as specified in the /etc/hosts file, the Domain Name Server, or the Windows Internet Naming Service). If this environment variable is not specified, the client will not connect to a secondary server.

See the Operations SentinelAdministration and Configuration Guide for details on using the Operations Sentinel Configuration application to specify a secondary server.

After the Operations Sentinel administrator has specified the secondary server, you can display its name and network address using the Configuration application. Use this information to set the environment variable SPO_EVENT_SECONDARY to ensure consistency with the agents supplied by Unisys that support a secondary server. Click Applications in the main menu bar, and then click Specify Secondary SPO Server. The dialog box that appears includes the server name and its network address. Click Cancel to close this dialog box.

Alternatively, you see the name and network address of the secondary server in the file

sp-data-folder\data\SPO-secondary

where sp-data-folder is the data folder specified during installation of the server version of Operations Sentinel.

If the administrator uses the default data folder, the location of this file is

C:\Documents and Settings\All Users\Application Data\Unisys\Operations Sentinel\x.y.z\data (level 11.x)

where x.y.z is the release level of Operations Sentinel.

File Format for SPO-Secondary

The format of the file is:

        secondary-name
        secondary-addr
        reserved
      

secondary-name

is the name of the secondary Operations Sentinel server.

secondary-addr

is the network address of the secondary Operations Sentinel server.

reserved

is any text or special characters. This field is reserved for future use.

Each field in this file appears on a line by itself.

Event Report for Switch of Servers

When a switch between servers occurs, the Event Server API sends an alert event report on behalf of the client, reporting that the Event Server switched to the primary or secondary server, whichever is the case. The API (linked with the client application) sends this event report to any Operations Sentinel server that is connected.

The following fields are included in this event report:

TYPE = AL
SEV = major
APPL=spues                (Single Point Universal Event Server)
APPLQUAL=application-name (as specified for SPD_InitClient)
ALARMID=_SwitchToPrimary  (or _SwitchToSecondary, depending on which case applies)

This alert must be manually cleared.

Like any alert event report, an alert raised when servers are switched is logged by Operations Sentinel. This alert is recorded in the logs named SPO and SP-SPALS, but is not recorded in the log of each monitored system. If several client applications report the switch of servers, only one alert appears in the Alerts windows of Operations Sentinel Console, because subsequent alerts are treated as duplicates. Any subsequent alerts (before the first alert has been cleared) are recorded as discarded raises (type DR) in the logs.

If an operator clears this alert before all clients have raised it, the alert reappears when another client sends the event report raising it.

You can examine the SPO and SP-SPALS logs using the Operations Sentinel Log Viewer. See the Operations Sentinel Console User Guide.