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uberAgent’s Driver Safety Net Feature

To collect high-quality network and process metrics, uberAgent relies on kernel-mode drivers that are started when the computer boots. While we invested a lot of time and energy to make our drivers as reliable as humanly possible, a driver is just a piece of software, and even software developed to the highest standards cannot be tested in all of the millions of possible combinations of hardware and software. One of the worst possible situations is a driver that crashes during the machine startup phase, more specifically during every machine startup. In such a bluescreen loop situation it can be difficult to restore the operating system to working order.

uberAgent’s drivers come with Driver Safety Net, a unique feature that prevents bluescreen loops: in the unlikely event of a crash in one of uberAgent’s drivers, the driver disables itself.

How Driver Safety Net Detects Crashes

In a nutshell, Driver Safety Net works as follows: uberAgent’s drivers write their current states to a location in the registry. The information from these registry values is used during the driver initialization phase. When a driver determines that its last start was unsuccessful it increments a failure count value. Once that count reaches a threshold of 3 (three), the driver disables itself.

False Positives

There are events that “look and feel” like a blue screen but have very different root causes, for example, power outages or hardware failures. If multiple such events occur in a short timeframe, uberAgent’s Driver Safety Net may be triggered, even though no driver crashed.

How to Re-Enable uberAgent’s Drivers After Driver Safety Net Triggered

Once Driver Safety Net triggers, uberAgent’s drivers remain disabled until re-enabled with the simple procedure outlined below. This is to ensure maximum system stability and reliability.

To re-enable uberAgent’s drivers remove the following registry values and restart the uberAgent service:

  • DrvFailureCount
  • DrvStartupFinished
  • DrvShutdownFinished
  • DrvLastStart

Depending on the driver that triggered Driver Safety Net, the above registry values are located in one of the following two registry paths:

  • Process driver: HKLM\SYSTEM\CurrentControlSet\Services\UberAgentDrv
  • Network driver: HKLM\SYSTEM\CurrentControlSet\Services\uberAgentNetMon


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