N|Solid Documentation


Threshold Alerts

Threshold Alerts allow you to instruct N|Solid to take certain actions (such as taking heap snapshots or CPU profiles) when one or more processes cross over performance thresholds that you set.

Often, performance problems occur in production code non-deterministically and the only information you have available to diagnose the situation is in an error log or possibly a stack trace. With N|Solid's Threshold Alerts, you can automatically capture more useful information when problems arise in production.

Setting Threshold Alerts with the N|Solid Console

  1. From the main application page, click on an application to enter the cluster view. Click on Threshold Settings, located near the upper-right corner of the page.

  2. There are two types of thresholds to choose from: Heap Used and CPU Used. You may configure actions independently in both.

  3. To enable a threshold, click the switch immediately below the ENABLE THRESHOLD label.

  4. Depending on the threshold you selected, drag either the maximum heap percentage or maximum CPU percentage slider immediately below the switch. Set this value to the ceiling you do not wish your application's processes to exceed during normal operation. When enabled, there will be a dotted red line in the corresponding graphs that indicates where the threshold is set.

  5. Next, set the threshold delay. This setting allows you to prevent short blips of activity, which do not necessarily indicate an issue, from triggering a threshold.

  6. As threshold actions can themselves be resource intensive, the threshold snooze setting ensures that the performance of your application does not suffer due to excessive profiles or snapshots and that your inbox is not inundated with repeated notifications.

    Note: When a threshold is set, a draggable bar for that threshold will appear in the cluster view. To change its value, click and drag the square handle at the center of the bar. To quickly open the Threshold Settings panel, double-click the square handle.

  7. Now that you have configured your threshold parameters, select one or more actions that N|Solid will perform when a threshold is triggered:

    1. Initiate CPU Profile: Select this option if you suspect that your application suffers from high CPU utilization. When enabled, N|Solid will start a CPU profile on your behalf and create an entry in the CPU profiles list in the process view.
    2. Take Heap Snapshot: Select this option if you suspect a memory leak. When enabled, N|Solid will take a heap snapshot on your behalf and create an entry in the memory profiles list in the process view.
    3. Send a Notification: Select this option to have alerts emailed to you. Separate multiple email addresses with a comma.

  8. Finally, don't forget to click click the Update button to save your settings.

Note: Be careful about setting a very high threshold, such as 99% Heap, and then selecting an action that uses the same resource, such as Take Heap Snapshot. Taking an intensive action at a very high ceiling is likely to negatively impact your application.