question Re: Uninstall Knox and installing again in Archives of Support Questions (Read Only)

Uninstall Knox and installing again

hammad_ali — Tue, 21 Apr 2026 12:32:52 GMT

Hi Guys,

We setup a new HDP cluster with Ambari version 2.1, with HDP version 2.3.4 and Knox version 0.6, after successful installation of knox for the first time, we tried to configure it with LDAP and tried to restart the knox gateway service, which didn't work and it seemed to be a bug which will be resolved in the next version of Ambari, then we thought to Delete Knox service via REST API and install it once again with Ambari, which is not working now as at the end of setup from Ambari we only get and error message "server error" from Ambari. Any ideas or suggestions that what should be the next step? Thanks in advance.

Regards,

Hammad Ali

Re: Uninstall Knox and installing again

nsabharwal — Sat, 06 Feb 2016 18:32:37 GMT

@Hammad Ali

You can delete knox through rest api

Run this in Ambari host

curl --user admin:admin -i -H "X-Requested-By: ambari" -X DELETE http://`hostname -f`:8080/api/v1/clusters/clustername/services/KNOX

Restart ambari server and see whats in the logs.

Clear broweser cache and try to login

Re: Uninstall Knox and installing again

aervits — Sat, 06 Feb 2016 20:18:26 GMT

@Hammad Ali Ambari 2.2 is out, why not go with that?

Re: Uninstall Knox and installing again

hammad_ali — Sun, 07 Feb 2016 18:41:27 GMT

@Neeraj Sabharwal Thanks for your answer, I deleted the Knox service with the above mentioned command, which i tried many time before too, when i checked on ambari the service is gone, then I restarted the ambari server and I found the this exception in the logs:

Local Exception Stack: Exception [EclipseLink-4002] (Eclipse Persistence Services - 2.5.2.v20140319-9ad6abd): org.eclipse.persistence.exceptions.DatabaseException Internal Exception: org.postgresql.util.PSQLException: ERROR: duplicate key value violates unique constraint "clusterservices_pkey" Detail: Key (service_name, cluster_id)=(KNOX, 2) already exists.

Moreover I can see the knox service with yellow sign once again in the ambari, my assumption is that the service is not being deleted from ambari database properly due to which I am also unable to install it once again.

Any feedback or advice, what is happening actually and how to proceed (we might need to delete it from database)?

Thanks in advance.

Hammad Ali

Re: Uninstall Knox and installing again

abajwa — Sun, 07 Feb 2016 18:57:02 GMT

You can remove it from the PostgresDB by runnign below from Ambari node:

su postgres
psql
\c ambari

DELETE FROM ambari.hostcomponentstate WHERE service_name IN ('KNOX');
DELETE FROM ambari.hostcomponentdesiredstate WHERE service_name IN ('KNOX');
DELETE FROM ambari.servicecomponentdesiredstate WHERE service_name IN ('KNOX');
DELETE FROM ambari.servicedesiredstate WHERE service_name IN ('KNOX');
DELETE FROM ambari.clusterservices WHERE service_name IN ('KNOX');

Re: Uninstall Knox and installing again

nsabharwal — Sun, 07 Feb 2016 19:40:03 GMT

@Hammad Ali For future referece 🙂 You can replace zepplein with KNOX

https://community.hortonworks.com/questions/577/on-ambari-211-centosrhel-7-removed-service-keeps-r.html

Re: Uninstall Knox and installing again

amcbarnett — Tue, 09 Feb 2016 12:15:25 GMT

HDP 2.3.4 Needs Ambari 2.2. You cannot use Ambari 2.1

Re: Uninstall Knox and installing again

nsabharwal — Tue, 09 Feb 2016 12:18:45 GMT

@Ancil McBarnett See this http://docs.hortonworks.com/HDPDocuments/Ambari-2.2.0.0/bk_Installing_HDP_AMB/content/_determine_stack_compatibility.html

You can use HDP 2.3 with Ambari 2.1

Re: Uninstall Knox and installing again

hammad_ali — Tue, 09 Feb 2016 15:46:06 GMT

@Ali Bajwa Thanks for this, deletion of service from Ambari database worked for me, after that i restarted Ambari and i was able to install new fresh version of Knox again.

Re: Uninstall Knox and installing again

nsabharwal — Sun, 14 Feb 2016 23:52:40 GMT

@Hammad Ali FYI ..Deletion is combination of both actions.

Re: Uninstall Knox and installing again

nsabharwal — Sun, 14 Feb 2016 23:53:27 GMT

Adding step for 1 for future users

Step 1) curl --user admin:admin -i -H "X-Requested-By: ambari" -X DELETE http://`hostname -f`:8080/api/v1/clusters/clustername/services/KNOX

Step 2) Ali's workaround

Re: Uninstall Knox and installing again

muanang — Wed, 03 Aug 2016 07:53:07 GMT

This works 100%

Thanks @Ali Bajwa and @Neeraj Sabharwal