How to change interval for Is-alive?

Solution

Microsoft Cluster Server (MSCS) uses poll intervals to determine the status of the resources it is protecting. The "Looks Alive" poll occurs frequently, performing a quick check to verify that the resource is still running, while the "Is Alive" poll performs a more comprehensive check of the resource and occurs less frequently.

Please follow the steps below to change the default poll intervals for a resource type in a cluster:

1. Open the ClusterX client, and highlight the cluster with the resource type to be changed (see Figure 1).
2. Select the "Configuration" view. This will show a list of every object contained in the cluster, including the resource types (see Figure 2).
3. Highlight the resource type that is to be changed, right-click, and select "Properties..."
4. Change to the "Poll Interval" tab (see Figure 3).
5. Make the appropriate poll interval changes, and click OK.

Figure 1:

Figure 2:

Figure 3

 

Looks Alive Vs Is Alive

Looks Alive 

check:Looks alive check is a basic resource health check to verify that the service(SQL service in our context) is running properly. To perform this , cluster service queries the windows service control manager to check the status of the service. By default looks alive check will happen in every five seconds.

Is Alive check: 

An exhaustive check to verify that a resource is running properly. If this check fails, the resource is moved offline and the failover process is triggered. During the Is alive check the cluster service connects to the SQL server instance and execute select @@SERVERNAME. It will check only the SQL server instance availability and does not check the availability of user databases.