QuerySurge uses disk space for storage for all QuerySurge information, including your QuerySurge assets, your 'raw' data, your results data and your scheduling. Eventually, as you use QuerySurge, disk usage will rise until all available disk space is consumed. Once there is insufficient space on a disk to support QuerySurge, application behavior can become unpredictable. QuerySurge includes a Disk Monitoring feature in order to help avoid problems related to disk usage.
QuerySurge and Disk Usage
Before we look at how Disk Monitoring works, it is important to understand how QuerySurge uses disk space.
The QuerySurge database uses disk space both as permanent storage, as well as for temporary storage during execution. Temporary disk usage during execution may consume significant amounts of space – enough to fill a disk entirely, depending on how much free space is available and how large the resultsets are. After execution is complete, the temporary storage is released.
Note that, if the disk becomes full during execution due to the temporary storage, this is the same as if the disk becomes full due to the level of permanent storage - QuerySurge may behave unpredictably. It is critical that full disk conditions must be avoided at all times, especially during execution.
Disk Usage Notification Threshold Levels
Alert Threshold Levels
QuerySurge Disk Status notification uses two notification thresholds: a lower threshold of disk consumption where users are issued a Warning message, and an Critical threshold where users are notified that disk usage has reached a critical point. The Critical alert threshold means that immediate action is required to free up disk space.
Modifying the Warning and Critical Alert Thresholds
The thresholds are managed in the QuerySurge Administration view. Navigate to Configuration > Server Properties in the tree.
The default settings are:
- Disk Usage Warning Threshold: 75% disk consumption
- Disk Usage Critical Threshold: 90% disk consumption
Note: The Disk Usage Warning Threshold must always be less than the Disk Usage Critical Threshold.
QuerySurge monitors the disk usage in two different intervals, depending on whether tests are executing or not. This is because disk usage can rise rapidly during execution and is increasing slowly when users are performing non-execution tasks. Therefore, the monitor interval is shorter during execution than when QuerySurge is not executing.
Modifying the Monitoring Intervals
The thresholds are managed in the QuerySurge Administration view. Navigate to Configuration > Server Properties in the tree. There are no restrictions imposed on these intervals, but generally the Idle Disk Usage Ping Interval will be the larger of the two.
The default settings are:
- Idle Disk Usage Ping Interval: 60 sec
- Running Disk Usage Ping Interval: 5 sec
Note: If you modify the Ping Interval, it will not take effect until the QuerySurge Statsmon service is restarted.
Monitored Disk Locations
The system monitors the following locations:
- The drive on which the MySQL data directory is located.
- The drive on which the MySQL temporary directory is located.
- The MySQL data directory itself.
- The MySQL temporary directory itself.
Note: Depending on your Operating System and configuration, some of these values may coincide.
Disk Usage Notifications
If any of the monitored locations exceeds a notification threshold (see above), a pop-up notification will be displayed to all users. Your pop-up will look like:
Any user not currently logged on at the time the condition occurs will see the popup on the next login. QuerySurge filters so that only critical notifications are displayed upon login.
Note: Pop-up alerts are displayed only once for each user when a notification threshold is reached, with the following exception: at login, users will receive a pop-up alert if disk usage is still above the Disk Usage Critical threshold. This popup shows even if the user previously received a pop-up alert during the previous session. QuerySurge notifies users in the manner because Critical alerts represent a condition requiring immediate attention.
Disk Usage Widget
The QuerySurge Widget library has a Disk Usage widget that displays the disk usage over time.
What to do if you receive an alert
If you receive an alert, it is time for disk management, without delay. A QuerySurge Admin user will need to remove results data from the QuerySurge database to recover disk space for ongoing work. See this Knowledge Base article on options for managing your disk usage.
IMPORTANT! When you start receiving an alert, do not delay disk management procedures. You may be less than a single action or execution away from a full disk.