Agent Group - Agent Mapping Advanced Settings

Use the Agent Mapping Advanced Settings dialog box to dynamically configure Agents that match the Agent Mapping. The Advanced settings let you:

  • Adjust communication buffers and specify a timer type that applies to a group of agents.
  • Set agent log level.
  • Enable hot sensor placement, Leak Analysis Memory Snapshot automatic generation, and Trending / Leak Analysis Memory Snapshot creation for .NET CLRs.
  • Adjust auto-sensor resolution for tolerable overhead.

Access the Agent Mapping Advanced Settings dialog box

  1. In the desired System Profile, expand the Agent Group, then select Agent Mapping.
  2. In the Agent Mapping dialog box, click Advanced to open the Advanced Settings dialog box.

Agent Mapping advanced settings

Buffer saturation threshold: If the Agent's communication buffer is filled above this threshold, no new PurePaths are added to the buffer until the buffer empties below the threshold. This increases the amount of correct PurePaths in certain Agent overload scenarios.

Buffer Size and Count: Define the overall size of the Agent communication buffer. Overall size is about equal to size * count.

Timer: Specifies a specific timer type to use for measuring method execution time.

Timers measure method execution time. Different timers provide different accuracy and granularity, based on the OS and architecture.

If a selected timer is not available on the agent platform, the Agent uses the standard run-time (Low-Res System Clock) timer. If changing the timer type, you must restart the Agent for the change to take effect.

Use the Agents Overview Dashlet to see the timer used by a specific Agent. To do this, select the desired Agent in the Agent list. The HiResClock and Timer properties in the Details pane indicate the type of timer for the Agent.

Select the timer to be used for the Agent. See Agent Timers for descriptions of each timer type.

Agent Log Level: Override the Agent's default log level.

Hot Sensor Placement: Enable/Disable Hot Sensor Placement. If set to Automatic the Agent enables Hot Sensor Placement automatically if supported by the underlying VM. Older JVM's do not support Hot Sensor Placement or certain JVM versions contain bugs that prohibit Hot Sensor Placement use.

Resource Exhausted Notifications (only available when Java is enabled for System Profile): Enable/Disable automatic generation of a Leak Analysis Memory Snapshot in case a Java 6 VM reports an Out-of-Memory notification. This option is not visible if Java is not selected on the General pane of the System Profile. Enabling it only affects Java agents.

.NET Trending/Leak-Analysis Memory Snapshot: Enable or disables Trending / Leak Analysis Memory Snapshot creation for .NET CLRs. By default, this is set to Automatic. This means that this is determined by the CLR version, but is off by default with any version. Off means no Memory Snapshots are possible and no additional overhead due to CLR notifications is necessary for Memory Snapshots. If set to Always On, run-time overhead increases even if no Memory Snapshot is created. Memory Snapshots for CLRs can be created. If you change this setting, restart the SUD. For ASP.NET, the AppPool must be recycled. When you see Agent configuration may cause high runtime overhead in the Start Center, take the appropriate action.

Note

Enabling this introduces a significant amount of overhead. Garbage collection times increase. Enabling this setting is not recommend in a production environment.

Auto Sensors (Extended PurePath Information): Auto Sensors adjust automatically to ensure they do not incur more overhead than the percentage setting. The amount of detail captured depends on the complexity of the application or environment. You may need to adjust the resolution settings until you see the desired level of detail for a tolerable amount of overhead. You can enable or disable Auto Sensors for the given Agent Group. You can also select the amount of information (known as resolution) provided by Auto Sensors to be stored in PurePaths. A higher resolution provides more detailed PurePaths, but causes more traffic between Agents and the Server.

Auto Sensors must be enabled to have sync and wait times.

You can enable or disable Extended PurePath information and adjust tolerable overhead dynamically at run time. See Sensors > Auto Sensor Resolution Settings for overhead and detail numbers and defaults in Editions.

Select the desired resolution level from the list box under Auto Sensors. The default setting is low for the Production Edition, medium for Pre-Production Edition.

The following table shows the typical percentage of overhead for each setting. Note the overhead highly depends on the instrumented application and the level of instrumentation.

Overhead in % Lowest Low Medium High Highest
Production Version 1 3 5 10 20
Non-Production 1 5 10 20 50

Changing the Advanced Settings does not require a restart.