Excessive request timeout health policy target timeout value

The excessive request timeout health policy specifies an acceptable percentage of requests that can time out after being routed from the on demand router (ODR). The target timeout value can vary depending on settings in your environment.

About the excessive request timeout health policy

The excessive request timeout health policy defines an acceptable percentage of timed out requests that are routed through the ODR. For each control cycle of the health controller, the number of requests that time out after being routed from the ODR is examined. If the percentage of timed out requests exceeds the configured percentage, runtime tasks are generated to correct the situation.

If you enabled Intelligent Management for your web server, the timeout value is determined using the read/write timeout in the web server plug-in cluster properties (serverIOTimeout in the plugin-cfg.xml file). The health policy calculates the percentage of timeouts over a 60-second interval.

Default values

By default, the target timeout value for requests is 60 seconds. The default value for the percentage of requests that can time out in the excessive request timeout health policy is 5%. However, setting other properties in your environment can affect the target timeout value that is used.

Settings that affect the timeout value

The following settings in the administrative console affect the target timeout value:

ODR outbound request timeout setting
To change the setting, click Servers > On demand routers > on_demand_router_name > On demand router properties > On demand router settings and set the ODR outbound request timeout value to a number of seconds.
ODR outbound request timeout for static ODR clusters setting.
To change the setting, click Servers > Clusters > On Demand Router Cluster > Cluster Name > On Demand Router Settings and set the ODR outbound request timeout value to a number of seconds.
ODR outbound request timeout for dynamic ODR clusters setting.
To change the setting, click Servers > Clusters > Dynamic Clusters > Cluster Name > Server Templates > On Demand Router Settings > On Demand Router Properties and set the ODR outbound request timeout value to a number of seconds.
goodServiceTimeLimitSpec custom property
For more information, read about autonomic request flow manager custom properties.
timeoutFactor custom property
For more information, read about autonomic request flow manager custom properties.
Average response time value that is defined in the service policy
To change the setting, click Operational policy > Service policy > service_policy_name. Specify Average response time as the Goal type and enter a Goal value.

Determining the target timeout value

Depending your configuration, the timeout value that is used as target value for the excessive request timeout health policy can vary. The following decision tree helps you determine the target timeout value for your environment. The default setting is the path indicated with red arrows, or a target timeout value of 60 seconds, which is the default setting for the ODR outbound request timeout.

Target timeout decision tree — Figure 1. Target timeout value decision tree .
The settings that affect the target timeout value combine together to indicate the target timeout value.

The value of the `goodServiceTimeLimitSpec` custom property is used as the target timeout value if the `goodServiceTimeLimitSpec` custom property is specified and is larger than the ODR outbound request timeout value.

The value of the ODR outbound request timeout setting is used as the target timeout value if the `goodServiceTimeLimitSpec` custom property is not specified, the `timeoutFactor` custom property is not specified, and the ODR outbound request timeout setting is set to less than 60 seconds.

The default value of 60 seconds is used as the target timeout value if the `goodServiceTimeLimitSpec` custom property is not specified, the `timeoutFactor` custom property is not specified, and the ODR outbound request timeout setting is set to greater than 60 seconds.

The timeout value is set to the product of the values of the `timeoutFactor` custom property and the average response time of the service policy if the `goodServiceTimeLimitSpec` custom property is not specified, the `timeoutFactor` custom property is specified, and the goal type of the service policy is set to average response time.