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This product reached the end of support date on March 31, 2021.

Web Server Agent


We recently upgraded/installed a newer dynatrace agent (6.2) across some windows servers since our previous agent is no longer fully compatible with the collector server version. The install and minor config changes appear to have gone successful. However i noticed on the agent dashlet a warning/error for the web server agent: Issue: Shared memory version mismatch: master and sub agents have different versions, details see logs). Any assistance on what this may mean and how to address it will be appreciated.


Dynatrace Leader
Dynatrace Leader

For web server agents there is a master web server agent that serves as the communication broker between the collector and the sub agent which is the agent that runs on individual sites/app pools. There will be issues like the error you mentioned if these are not the same version. Can you look at the agents overview dashboard and expand the given web server agent? You should see the master and the sub agent and in the details you will likely see that they are different versions. It is likely that the sub agent was not updated during the upgrade.

I believe if you restart whichever agent is the lower version it should recieve the updated agent version.


To add to what James is saying it sounds like you need to update your Master Web Server agent which can be done by restarting the Dynatrace Web Agent service


Thank you both you much for the guidance. On the two windows machines I see the error, I went and check on the Agent Overview dashlet for each server. Server 1 I noticed the master and sub web server agent having different versions. The sub agent still shows 5.5.0. On Server 2 both master and sub agents have the same version. I then re-started on both windows machines these two windows services:

- dynatrace host agent 5.5.0

- dynatrace web server agent 6.2

However it does not seem the restart was enough clear this mismatch. Not sure if followed the correct steps or additional actions are required.


While checking some of the configuration steps executed by our operations team we found out they missed in removing the older web server agent modules from the iis web site. This is what was causing the mismatch between the master and sub agents. Once we removed the older modules ensuring only the newer ones were active we restarted the windows service which cleared this issue. Thank you so much for your guidance really appreciate it.


Hi @James Kitson

Can you kindly provide clarity the on impact if this is not upgraded after the server has. How will this impact data (vists, web requests/transactions) should this be ignored? Will the web server have irregular activity or behavior?

In addition to this do you know of a method that we can generate an incident for such as issue?

Kind regards



Katlego, first we were not aware at all that our old 5.5.0 agents were no longer fully compatible with the recent 6.2 upgrade on the server\collector side. We knew there was backwards compatibility going some minor versions or a version and this was more clear to us as we visited an article on Dynatrace's site. Our IT team responsible for the Dynatrace collector/server were the ones who informed us. Unfortunately I cannot fully quantify the immediate effect of the server collector upgrade while our app server agents remained unchanged. I can confirm that we could still see purepaths and we could also see UEM related data. Probably, its going into specifics to really find out where you find areas of incompatibility. Yes we did a high level smoke test after the server collector upgrade to ensure we could see still see data through our profiles but we did not find issues at that high level validation effort. Perhaps would be a question for the vendor to find out exactly what areas are affected with incompatibility. We worked quickly in upgrading our agents so we are now matching the collector version.