Configure Application Performance Score Objects

Go to Configuration > Objects > Service Levels > Application Performance Score.

1. Click the Add New APS Object button.
2. Type a name for the score.
3. In the Application list, select the application traffic to monitor.

4. If you want to just monitor the application for a particular internal network object, specify the desired internal network object; otherwise select ALL.

5. If you want to just monitor the application for a particular external network object, specify the desired external network object; otherwise select ALL.

   By specifying both the internal and external network object, only the application conversations between the specified network objects will be tracked.

6. If you want to be alerted when the application performance score drops below a particular threshold, set the alert settings.

   See 'To configure the system to send a notification when the APS score is too low' section below.

7. Set the thresholds for the APS metrics either by having the system automatically baseline the traffic to determine the thresholds or by manually setting the thresholds.

   See 'To manually set the threshold values' and 'To automatically calculate the thresholds by baselining the traffic' sections below.

8. If the application uses a non-transactional protocol for traffic between the client and server, such as Citrix XenApp Servers or Microsoft Remote Desktop, select the Non-Transactional Protocol checkbox.

9. Click Add New APS Object.

   The object is added to the list of configured APS objects.

Metric thresholds can be set manually when initially creating the APS object or upon editing an APS object even if they were automatically determined by the baselining operation. For example, if the baselining operation set all of the thresholds and you really only care about round trip time, normalized server delay, and normalized network delay, then you can remove the threshold settings for the other metrics.

1. On the Add New APS Object form, uncheck the Auto Baseline checkbox. Note if a baseline analysis is running, you'll need to press the Stop Baseline button. The threshold values are only editable there is not a baseline running. The metrics will appear on the screen.

   Or edit the APS object in the list, then on the Edit APS Object form, the Scoring Metrics appear at the bottom of the form.

2. Enter or modify the values for the metrics that you are interested in setting thresholds for. Note that any metric that does not have a threshold set will not be analyzed when calculating the APS score.

   • Network delay – the time taken for data to traverse the network (on the wire) in one direction from the client through the Exinda appliance to the server (or in the opposite direction) in ms
   • Server delay – the time taken for a server to respond to the request in ms
   • Normalized network delay – the time taken for data to traverse the network in one direction, where the delay is measured independent of the transaction size by assuming a normalized packet size of 1024 bytes
   • Normalized server delay – the time taken for a server to respond to the request, where the delay is measured independent of the transaction size by assuming a normalized packet size of 1024 bytes
   • Round-trip time – the time taken for a packet to travel from a client through the Exinda appliance to the server and back
   • Jitter – the measure of variability of network delay, defined as one standard deviation of normalized network delay
   • Inbound loss – the percentage of packet loss on inbound traffic
   • Outbound loss – the percentage of packet loss on outbound traffic

3. Click Apply Changes.

To save the changes to the configuration file, in the status bar click the Unsaved changes menu and select Save configuration changes.

The baselining process can be started when initially creating the APS object or upon editing an APS object. At any time you can restart the baselining process if you would like the system to recalculate the thresholds.

1. On the Add New APS Object form, ensure that the Auto Baseline checkbox is checked and set how long you want the system to observe traffic when calculating the thresholds by using the Auto Baseline Period drop-down list.

   Select the time period for the baseline based on how popular the application is. For example, if there is a lot of HTTP traffic on the network, the 1 hour period will be long enough to analyze traffic and create an accurate baseline. For an application that is not used very often, use the 1 week baseline period to ensure that enough traffic is analyzed to generate baseline recommendations.

2. Or on the Edit APS Object form, set the Auto Baseline Period and click the Start Baseline button.

	Note The Network Loss metric is not calculated during the baseline analysis.

Note If no traffic matching this APS object is observed during the baseline period, the appliance restarts the baseline analysis for the next larger time period. For example, if no traffic observed during the one hour period, the traffic continues to be analyzed for one day. If no traffic is observed during the one day period, then the traffic is analyzed for a week. If the traffic is analyzed for one week and no traffic has been transferred, the auto baseline analysis stops. Each time the system unsuccessfully baselines the traffic (that is, when no traffic is observed during the auto baseline period), an email notification is sent to the users configured on the Configuration > System > Network > Email page.

1. On the Application Performance Score configuration tab, the list of APS objects is shown. If the APS is currently baselining the application traffic, there will be a green checkmark in the Auto Baseline column.
2. Press the Edit button for the APS object. The Baseline Info section specifies the status (Running or Stopped) and the Start and End Date and time of the baseline period. Note that it also shows the average packet size and the amount of traffic seen.

Alerts can be enabled when initially creating the APS object or upon editing an APS object.

1. Ensure the Alert Enable checkbox is checked.

2. In the APS Threshold field, specify the APS user experience score threshold value below which you would like a notification to be sent. This threshold must be between 0 and 10.

3. In the Alert Trigger Delay field, specify how long you would like the APS user experience score to be below the threshold before the notification is sent. This threshold is measured in minutes.

E X A M P L E If the alert threshold is set to 7.0 and the alert trigger delay is set to 5 minutes, then the alert needs to be below 7.0 for 5 minutes before the alert is triggered.

	Note Ensure that the Send Email alert is enabled for this on the Configuration > System > Setup > Alerts page. Valid SMTP and email settings are required for email alerts. To configure, see SNMP Configuration and Email Configuration.

Applications like Citrix XenApp server or Microsoft Remote Desktop use non-transactional protocols that send information between the client and server at arbitrary times. With these types of applications, the standard method of calculating the Application Performance Score (APS) does not produce an accurate metric. If the application uses a non-transactional protocol, you must specify that when creating APS object.

When creating the APS object, ensure the Non-Transactional Protocol checkbox is selected.

Yes. You can modify the thresholds either manually or by re-starting the baseline analysis. You can also enable an alert. You can change the internal and/or external network object setting to monitor the application for a subset of your network.

	Important Do not change which application is being monitored. It is not recommended to change the name of the APS object.

To learn how round trip time, network delay, server delay, network jitter, and packet loss are calculated (as well as, total transaction delay), read How Network Performance Metrics are Calculated.

The network performance metrics are calculated based on the observed traffic. Each threshold is calculated to be 0.85 standard deviation above the average observation for that metric. This ensures that the calculated thresholds target an APS of 9.0. If the application reports an APS below 9.0, the application is performing worse than the baseline.

To learn how the application performance score is calculated, read How an Application Performance Score is Calculated.