Cluster Node installation and the OneAgent user

[gautier_begin]

Hello,

During the installation of the cluster node, an oneagent is also installed.

Because any user used by any software must be created by our UNIX team, I'm using the argument "

system-user" . That's working for the server installation, but not for the oneagent installed with. The dtuser is still created and used by the oneagent. How to get by ?

Regards,

[gautier_begin]

Can we install the server without the OneAgent, then install it with custom arguments using the installer script download from the

SELFMON_AGENT_DOWNLOAD_URL

parameter in the server installer config file ?

[kristof_renders]

Hi Gautier,

You can disable the agent installation by adding the following parameter to the installer:

--install-agent <on/off>  enable/disable installation of self-monitoring
                             agent. Default is on

Not sure about being able to install it after the fact, maybe somebody else can answer that one.

KR,
Kristof

[fstekelenburg]

Unfortunately the (re)install after question has not been answered.
I started a new topic on this https://answers.dynatrace.com/spaces/482/dynatrace-open-qa/questions/244698/installation-oneagent-on...

But am in contact with support now over this,

[gautier_begin]

Hi Kris,

On already installed node, how to remove the agent ?

Regards,

[Radoslaw_Szulgo]

just run the uninstaller of OneAgent from /opt/dynatrace/oneagent

or run ./reconfigure with

--install-agent off

[gautier_begin]

Hello,

Reinstallation of the node on the same machine, same address IP drives to one issue with the cassandra DB which doesn't want to start.

You get this error message:

ERROR [main] 2017-12-06 12:20:57,938 CassandraDaemon.java:583 - Exception encountered during startup
java.lang.RuntimeException: A node with address /10.137.10.95 already exists, cancelling join. Use cassandra.replace_address if you want to replace this node.
at org.apache.cassandra.service.StorageService.checkForEndpointCollision(StorageService.java:544) ~[apache-cassandra-2.1.18.jar:2.1.18]
at org.apache.cassandra.service.StorageService.prepareToJoin(StorageService.java:794) ~[apache-cassandra-2.1.18.jar:2.1.18]
at org.apache.cassandra.service.StorageService.initServer(StorageService.java:726) ~[apache-cassandra-2.1.18.jar:2.1.18]
at org.apache.cassandra.service.StorageService.initServer(StorageService.java:617) ~[apache-cassandra-2.1.18.jar:2.1.18]
at org.apache.cassandra.service.CassandraDaemon.setup(CassandraDaemon.java:391) [apache-cassandra-2.1.18.jar:2.1.18]
at org.apache.cassandra.service.CassandraDaemon.activate(CassandraDaemon.java:566) [apache-cassandra-2.1.18.jar:2.1.18

It can be corrected using this workaround:

https://blog.alteroot.org/articles/2014-03-12/replace-a-dead-node-in-cassandra.html

Add in the

cassandra-env.sh

file these lines:

LOCAL_IP=$( nslookup
$(hostname) | awk -F': ' '{if ( $1 == "Address"){print $2}}' )

JVM_OPTS="$JVM_OPTS
-Dcassandra.replace_address=$LOCAL_IP"

Stop/start Cassandra

Remove the lines in
./server/bin/cassandra/conf/cassandra-env.sh

Stop/start Cassandra

Stop/start the server

• Resinstallation
  finished

Regards,

[Radoslaw_Szulgo · Accepted solution]

To run OneAgent with a different user, run installer with:

--agent-system-user <user:group>