PRTG Manual: Passive Application Performance Sensor
This Sensor Type Is Deprecated! |
|---|
This sensor type is deprecated. We provide the documentation in this section for your information only. We removed this sensor type from PRTG with version 16.x.25 (expected in May 2016). Your sensor will then stop monitoring and show a Down status. See the following article for details and possible alternatives for deprecated sensors: Knowledge Base: The PRTG Sensor Cleanup |
The Passive Application Performance sensor monitors Transmission Control Protocol (TCP) connection timings using packet sniffer. It can measure the performance of many different web applications without actually having direct access to neither the client nor the server. To obtain valuable data, these applications must work TCP-based and initiate a new session with each request.
The sensor can show the following:
- Total number of packets per second on the selected network card
- Number of dropped packets per second by PRTG because of system overload (more processor power is required if this value is above zero to cope with the traffic)
- Number of currently active connections on all monitored applications.
For defined applications, the sensor can show (together with the corresponding application name):
- Request time in msec: average time between the initial (SYN) packet from the client and the first request package from the client
- Response time in msec: average time between the initial (SYN) packet from the client and first packet of the result from the server
- ACK (acknowledge) time in msec: average time between the initial (SYN) packet of a connection from the client until the server sends an ACK (acknowledge) packet. This means that a TCP connection was successfully established (in LANs this value is zero in most cases and only increases for extreme loads).
- Count: total number of observed connections to the service in the last monitoring interval. This is the number of measurements the average is based on. The higher the value the more reliable/averaged the data is. If this value is zero, PRTG did not see any packets for this service.
Passive Application Performance Sensor
Click here to enlarge: http://media.paessler.com/prtg-screenshots/passive_application_performance.png
- For a general introduction to the technology behind packet sniffing, see section Monitoring Bandwidth via Packet Sniffing.
- This sensor can have a high impact on the performance of your monitoring system. Use it with care. We recommend that you use no more than 50 sensors of this sensor type on each probe.
The Add Sensor dialog appears when you manually add a new sensor to a device. It only shows the setting fields that are required for creating the sensor. Therefore, you do not see all setting fields in this dialog. You can change (nearly) all settings in the sensor's Settings tab later.
Click the Settings tab of a sensor to change its settings.
Usually, a sensor connects to the IP Address or DNS Name of the parent device on which you created the sensor. See the device settings for details. For some sensors, you can explicitly define the monitoring target in the sensor settings. See below for details on available settings.
Setting |
Description |
|---|---|
Sensor Name |
Enter a meaningful name to identify the sensor. By default, PRTG shows this name in the device tree, as well as in alarms, logs, notifications, reports, maps, libraries, and tickets. |
Parent Tags |
Shows tags that this sensor inherits from its parent device, group, and probe. This setting is shown for your information only and cannot be changed here. |
Tags |
Enter one or more tags. Confirm each tag with the Spacebar key, a comma, or the Enter key. You can use tags to group objects and use tag-filtered views later on. Tags are not case-sensitive. Tags are automatically inherited. You can add additional tags to the sensor. There are default tags that are automatically predefined in a sensor's settings when you add a sensor.
|
Priority |
Select a priority for the sensor. This setting determines where the sensor is placed in sensor lists. A sensor with a top priority is at the top of a list. Choose from one star (low priority) to five stars (top priority). |
Applications |
|
|---|---|
Network Adapter |
Select the network adapter that you want to monitor. |
Applications |
Define the applications that you want to monitor. For each application, use one dedicated line. Use the following syntax to define an application to be monitored: ip:port=application. Provide the IP address and port number of the application. Behind the equals sign, enter a name for the application which will be displayed in the channels. Enter a string. This sensor will create four channels with the application name, for example, "Application (ACK)". |
Setting |
Description |
|---|---|
Primary Channel |
Select a channel from the list to define it as the primary channel. In the device tree, the last value of the primary channel is always displayed below the sensor's name. The available options depend on what channels are available for this sensor.
|
Graph Type |
Define how different channels are shown for this sensor:
|
Stack Unit |
This field is only visible if you enable Stack channels on top of each other as Graph Type. Select a unit from the list. All channels with this unit are stacked on top of each other. By default, you cannot exclude single channels from stacking if they use the selected unit. However, there is an advanced procedure to do so. |
By default, all of the following settings are inherited from objects that are higher in the hierarchy and should be changed there if necessary. Often, best practice is to change them centrally in the root group settings. For more information, see section Inheritance of Settings. To change a setting for this object only, disable inheritance by clicking the button next to inherit from under the corresponding setting name. You then see the options described below.
Click 
to interrupt the inheritance. See section Inheritance of Settings for more information.
Setting |
Description |
|---|---|
Scanning Interval |
Select a scanning interval (seconds, minutes, or hours). The scanning interval determines the amount of time that the sensor waits between two scans. You can change the available intervals in the system administration on PRTG on premises installations. |
If a Sensor Query Fails |
Define the number of scanning intervals that the sensor has time to reach and check a device again in case a sensor query fails. Depending on the option that you select, the sensor can try to reach and check a device again several times before the sensor shows a Down status. This can avoid false alarms if the monitored device only has temporary issues. For previous scanning intervals with failed requests, the sensor shows a Warning status. Choose from:
|
Schedules, Dependencies, and Maintenance Window
You cannot interrupt the inheritance for schedules, dependencies, and maintenance windows. The corresponding settings from the parent objects are always active. However, you can define additional settings here. They are active at the same time as the parent objects' settings.
Setting |
Description |
|---|---|
Schedule |
Select a schedule from the list. Schedules can be used to monitor for a certain time span (days or hours) every week.
|
Maintenance Window |
Specify if you want to set up a one-time maintenance window. During a maintenance window, the selected object and all child objects are not monitored. They are in a Paused status instead. Choose between:
|
Maintenance Begins |
This field is only visible if you enable Set up a one-time maintenance window above. Use the date time picker to enter the start date and time of the maintenance window. |
Maintenance Ends |
This field is only visible if you enable Set up a one-time maintenance window above. Use the date time picker to enter the end date and time of the maintenance window. |
Dependency Type |
Define a dependency type. You can use dependencies to pause monitoring for an object depending on the status of a different object. You can choose from:
|
Dependency |
This field is only visible if you enable Select a sensor above. Click the Search button and use the object selector to select a sensor on which the current object will depend. |
Dependency Delay (Sec.) |
This field is only visible if you enable Select a sensor above. Define a time span in seconds for dependency delay. After the master sensor for this dependency comes back to an Up status, monitoring of the dependent objects is additionally delayed by the defined time span. This can prevent false alarms, for example, after a server restart, by giving systems more time for all services to start up. Enter an integer value.
|
Click to interrupt the inheritance. See section Inheritance of Settings for more information.
Setting |
Description |
|---|---|
User Group Access |
Define the user groups that have access to the object. You see a table with user groups and group access rights. The table contains all user groups in your setup. For each user group, you can choose from the following group access rights:
To automatically set all child objects to inherit this object's access rights, enable the Revert children's access rights to inherited option.
|
To change display settings, spike filtering, and limits, switch to the sensor's Overview tab and click the gear icon of a specific channel. For detailed information, see section Sensor Channel Settings.
Click the Notification Triggers tab to change notification triggers. For detailed information, see section Sensor Notification Triggers Settings.
For more general information about settings, see section Object Settings.
For information about sensor settings, see the following sections:
