Agents
This screen allows to modify on the fly data collected by HPA.
Those switches are managed by properties and configuration files loaded at the startup of the HPA agents. But this screen enables to modify their current values.
Change those values can have an impact on the HPA overhead.
The changes made via this screen are persisted on the file system as described here.
Data collection sessions monitors
The Data collection session monitor is an additional process running on each host where at least one HPA agent is running.
The data collection session monitor encapsulates and manages certain metrics captured by the data collection session, such as:
- Threads dumps
- Memory dumps
- JFR
Those metrics are captured in fine by a script steered by the data collection session monitor process.
Description of agents settings
Agents settings have 2 different types
- flag: activates the collection of some metrics
- service: activates a service running inside the agent - e.g.
HpaThreadStackServicewhich dumps JVM threads
| Name | Type | Comment |
|---|---|---|
| HpaConfigurationExportService | Service | Calypso configuration export for data collection session - described here |
| HpaDBExtractorService | Service | Calypso database data export for data collection session - described here |
| HpaStallService | Service | Allows the capture of stall metrics - described here |
| HpaThreadStackService | Service | Threads dumps every 10 minutes - used for method hotspots |
| HpaTraceService | Service | Used for Context tracer - activated by default |
| HpaUsageOverviewService | Service | Provides the DataServer compute time by DataServer client - used typically in the homepage |