Configure the maximum memory (heap size) of the On-Premise Poller to control how much system memory the application can consume. This helps ensure stable performance and prevents resource exhaustion.

Prerequisites

• Access to the On-Premise Poller installation directory.
• Administrative or root privileges in the system where the On-Premise Poller is installed.
• Details about available system memory (RAM).

By default, the On-Premise Poller allocates up to 80% of total system memory, which is suitable for most environments. Modify the heap size to increase or reduce memory usage based on monitoring workload and system resource availability. Ensure the configured values are appropriate for your environment, as incorrect values may impact monitoring performance. As a best practice, create a backup copy of the file before making any changes.

Configuring maximum memory in Linux

In Linux, you can manually set the heap size in the StartServer.sh file.

Steps

1. Navigate to the On-Premise Poller's installation directory.
2. Open the StartServer.sh file.
3. Locate the following section:
   # Optional manual override
   # maxHeapSize=8192
4. Uncomment the line and set the required value (in MB):
   maxHeapSize=8192
5. Save the file.
6. Restart the On-Premise Poller.
   
   

Notes

• The value is specified in MB.
• This overrides the default memory calculation.
• Ensure sufficient memory is available on the system before making changes.

Configure maximum memory in Windows

In Windows, you can configure max memory in the wrapper.conf file.

Configure using percentage

1. Navigate to the On-Premise Poller's installation directory.
2. Open the wrapper.conf file.
3. Locate:
   wrapper.java.maxmemory.percent
4. Set the required percentage value.

wrapper.java.maxmemory.percent=85

• Total system memory: 16GB
• Configured value: 85%
• On-Premise Poller maximum memory: 13.6GB

Configure using MB (manual override)

1. In the wrapper.conf file, locate:
   #wrapper.java.maxmemory=8096
2. Uncomment the line and set the required value in MB:
   wrapper.java.maxmemory
3. Save the file.
4. Restart the On-Premise Poller.

Notes

• Value is specified in MB.
• This overrides the percentage-based configuration.

When should you increase maximum memory?

Increase the On-Premise Poller's maximum memory (heap size) when you observe performance degradation or memory-related issues.

Common indicators

• Frequent OutOfMemoryError messages in logs.
• High memory utilization sustained over time.
• Slow data collection or delayed metric updates.
• On-Premise Poller becoming unresponsive or restarting unexpectedly.
• Increase in the number of monitored devices, interfaces, or flows.

Typical scenarios

• Adding a large number of devices to the On-Premise Poller.
• Enabling high-frequency polling.
• Monitoring flow data (NetFlow, sFlow, etc.).
• Collecting logs or handling high-volume telemetry.
• Running multiple monitoring modules on the same On-Premise Poller.

Before increasing memory

• Verify current memory usage at the OS level.
• Check On-Premise Poller logs for memory-related errors.
• Ensure additional RAM is available on the system.
• Avoid over-allocation that impacts other processes.

Quick tip

If memory usage is consistently high even after increasing heap size, review:

• Polling intervals.
• Number of monitored resources.
• Enabled monitoring features.

Best practices

• Allocate 70–85% of total system memory.
• Avoid assigning full system memory to the On-Premise Poller.
• Monitor memory usage after configuration changes.
• Restart the On-Premise Poller after updating settings.