Request for Guidance: Disabling OneAgent Process Injection During Installation

[MahmoudBeheiry]

Dear Support Team,

We are experiencing an issue on several Windows Exchange servers where the application impacted after deploying Dynatrace OneAgent. To minimize any impact, our deployment policy is to install OneAgent in Infrastructure Monitoring mode only 

Our understanding is that Infrastructure Monitoring mode should not perform deep process/code injection. However, we are still observing application impacted after the OneAgent installation on some servers.

During our troubleshooting, we found that when process injection is disabled, the application starts successfully and runs without any issues. This indicates that the issue appears to be related to the process injection mechanism.

Could you please confirm whether there is any supported method to completely disable process injection during the OneAgent installation? If not, could you advise whether there are any additional settings, monitoring rules, or best practices that should be applied to prevent process injection and ensure the OneAgent does not impact application availability on these Windows Exchange servers?

Any guidance on troubleshooting this behavior or recommendations for preventing application downtime during deployment would be greatly appreciated.

Regards,

Mahmoud.

[AntonPineiro]

Hi,

Yes, it is documented here and here. You can disable it during installation, or after.

Best regards

[kunal_vaidya]

Can someone from Dynatrace check and confirm if there are any compatibility issues with Exchange servers? 

[Mohamed_Hamdy · Accepted solution]

Hi Mahmoud,

Based on your description, you are already using OneAgent in Infrastructure Monitoring mode. One important point is that Infrastructure-only mode does not automatically guarantee that ProcessAgent injection is disabled.

You mentioned that when process injection is disabled, the application starts successfully and runs without any issues. Could you please clarify whether you specifically disabled ProcessAgent injection while keeping OneAgent running in Infrastructure Monitoring mode, or whether OneAgent itself was stopped/disabled? This distinction is important.

If the requirement is to use Infrastructure Monitoring without process injection, auto-injection can be explicitly disabled during the OneAgent installation using:

--set-auto-injection-enabled=false

If ProcessAgent injection was already active, the affected Exchange/IIS processes should be restarted after disabling it so that the previously loaded OneAgent modules are unloaded.

Installing OneAgent in Infrastructure Monitoring mode does not normally require application downtime or a service restart.

Note: Disabling ProcessAgent injection is generally not recommended as a permanent configuration unless required. Since you have already observed an application impact when injection is enabled, I would recommend raising a Dynatrace Support ticket and including the OneAgent support archive so Dynatrace can investigate the behavior and identify the exact root cause.

Best Regards,
Hamdy

[MahmoudBeheiry]

Dear Hamdy,

Thank you for your reply

We have opened a Dynatrace support ticket, and the Dynatrace team has recommended disabling ProcessAgent injection. Could you please clarify the impact on the Exchange/IIS services when we disable injection while keeping OneAgent in Infrastructure Monitoring mode? Specifically, I would like to know:

What performance or functionality changes we can expect.
Whether any additional steps are required to ensure that all OneAgent modules are fully unloaded.
Your guidance will help us assess the risk and plan the change safely.

Regards,
Mahmoud.

[Julius_Loman]

@MahmoudBeheiry  , you will lose some metrics which are captured using code modules (process agent) for the processes. For example, the number of IIS requests.  For unload the code modules, just restart of the processes with code modules inject is required. A reboot is not required, but I would recommend it in your case anyway.