Response Times

Concepts

Response times denote the time it takes to serve a web request or an EJB method call. Unlike numerical metrics, response time data is usually a tabular array of data rather than a single data point. For example, one response time metric provides you min/avg/max data for all methods of a Session Bean or all URLs of a web application.

Before you continue, you should make yourself familiar with Monitoring as a whole.

Enabling Response Time measurement

Before response times can be gathered or displayed, they first need to be enabled

EJB call times

In order to gather EJB call times you need to go to the configure section of the Monitor tab and enable the collection of the call times:

See the Collection Schedules section on the general Monitoring page for more information about collection schedules and defaults.

Web application response times

In order to gather response times from web applications, you need to instrument the servlet container. This process is described on the Response Time Filter page.

Note: the RHQ Server is already instrumented.

After the filter is installed, you need to go to the inventory tab of the web application and give the full path to the logfile:

There are two more properties that you want to set:

• URL Excludes: you can here specify URLs that should not be taken into account for the response time metrics. Examples are static pages like CSS files or favicons. Entries are regular expressions and need to be separated by spaces
• URL Transforms: If a page is called with different parameter, you might decide to show them as separate URLs or as one URL only. The transform allows you to rewrite URLs to e.g. strip off those parameters. Entries are regular expressions that are separated by spaces. The functioning of the URL transforms is depending on the settings of the Response Time Filter; especially the chopQueryString parameter.

After this is done, you need to go to the configure section of the Monitor tab and enable the collection of the reponse times:

See Monitoring#Collection schedules for more information about this.

Monitor Tab

For resources that can collect response times, you will see another subtab on the monitor tab named "Response time":

When you select it you will see two sections

• on the left the raw data table with the resource, number of calls and times

• on the right the call times visualized as bar diagrams

  Jopr 2.1 used bar diagrams, the latest code just shows the data in tabular form