How does Pulse determine if a TM1 instance is offline

It might happen that you are receiving an offline alert from Pulse but the TM1 instance is still running.

For Pulse, Offline means that the TM1 instance is not reachable. It could be due to the fact that the instance is stopped or if the instance is not reachable by Pulse.

Pulse makes a very fast REST API request every second to each TM1 instance to check if the instance is still reachable.

If the response from TM1 is not retrieved by Pulse in a certain time, Pulse will raise an Offline alert.

In the Pulse.cfg, you will find two timeout values:

• LocalConnectionCheckTimeout: when TM1 instances are self-hosted (default value is 500 Ms)

• RemoteConnectionCheckTimeout: when TM1 instances are hosted on IBM PA Cloud (default value is 3000 Ms).

The REST API request should take less than these timeouts. If your TM1 instance takes longer to send the information to Pulse, this is where you might get a false alert from Pulse. Pulse will raise an Offline alert while the instance is still Running because it did not get the response in time, Pulse will assume the instance is not reachable.

If this is the case, you should investigate the reason why these requests take longer than they should. Maybe the TM1 instance is under a lot of stress. If this is not the case the request is still taking more than the timeout.

You can increase these timeouts to reduce the chance of receiving offline alerts when the instance is still running. Do note that your Dashboard metrics may give you delayed information like the message logs due to the possible slowness of your TM1 server.