Activation of deep monitoring was unsuccessful after server restart

[ramzi_ait-sahal]

After restarting our environnement servers, we lost monitoring on some processes, and got the message "

"Activation of deep monitoring was unsuccessfull", we have tried uninstalling and reinstalling agents and restarting again but with no success.

[ChadTurner]

Do you have any security apps running on that host? I have seen where multiple security apps will either block the install, disable the oneagent and or totally revert the install hours later.

[ramzi_ait-sahal]

I need to check with servers admins but there probably is a Firewall/antivirus. Thing is it worked perfectly during first install, then it stopped working after restart of the monitored servers, and it kept not working after trying uninstallation and reinstallation of the agents.

One agent is monitoring the host, the problem concerns only some processes (tomcat and apache for the first host, and another process for the second host). For these three processes we keep having the same message:

"Activation of deep monitoring was unsuccessful"

[ramzi_ait-sahal]

Where can we check the logs or any info that will give us a clue ?

[ChadTurner]

You should be able to go to Dynatrace directory>oneagent>logs and review the data there.

[ramzi_ait-sahal]

Agent logs on problematic host revealed the following line:

2020-06-12 06:42:20.293 UTC [xxxx] info [native] URL https://<URL>:<PORT>/communication not working (Connection timed out after 2000 milliseconds) (occurred 20 times in the last 1h 0m 0s)

2020-06-12 06:48:30.296 UTC [xxxx] info [native] URL https://<dynatrace_host>.<dynatrace_domain>:<port>/communication not working (Couldn't resolve host 'host.domain.com') (occurred 10 times in the last 1h 0m 0s)

Seems like something was cut after restart ? but clearly host isn't reaching dynatrace server anymore

[ChadTurner]

Time out.... are you sure that the firewall rules are allowing the communication?

[AntonioSousa]

From the second line in the log, at least there seems to be an issue with DNS, as one host (not sure what it is) is not being resolved.

[ramzi_ait-sahal]

i'm checking with server admins, but nothing was changed since it worked the first time, except a full restart of hosts.

[ChadTurner]

Okay, keep up update, if the firewalls are good then check with your security team to ensure security apps arnt stopping it