Reinstalling the Services from Apache Ambari

This blog discusses on how to reinstall a component from Amabri. As an example, I have taken reinstallation of Knox.

IT IS RECOMMENDED TO GET PRODUCT TEAM INVOLVED BEFORE RUNNING THE BELOW PROCEDURE. PLEASE DO NOT TRY THIS PROCEDURE ON PRODUCTION CLUSTER DIRECTLY BEFORE TRYING IT IN YOUR DEVELOPMENT CLUSTER.

1) Stop the Knox


Syntax: curl -u admin:admin -H 'X-Requested-By: ambari' -i -X PUT -d '{"RequestInfo": {"context": "Stop KNOX REST"}, "Body": {"ServiceInfo": {"state": "INSTALLED"}}}' http://<AMBARI_IP>:8080/api/v1/clusters/<Cluster_Name>/services/KNOX


[root@bdavm621 nisan]# curl -u admin:admin -H 'X-Requested-By: ambari' -i -X PUT -d '{"RequestInfo": {"context": "Stop KNOX REST"}, "Body": {"ServiceInfo": {"state": "INSTALLED"}}}' http://bdavm621.com:8080/api/v1/clusters/BI_41/services/KNOX
HTTP/1.1 202 Accepted
User: admin
Set-Cookie: AMBARISESSIONID=1th1qyghm8v7vu39twhsrtpli;Path=/;HttpOnly
Expires: Thu, 01 Jan 1970 00:00:00 GMT
Content-Type: text/plain
Vary: Accept-Encoding, User-Agent
Content-Length: 148
Server: Jetty(8.1.17.v20150415)

{
  "href" : "http://bdavm621.com:8080/api/v1/clusters/BI_41/requests/179",
  "Requests" : {
    "id" : 179,
    "status" : "Accepted"
  }
}[root@bdavm621 nisan]#


2) Check the KNOX is stopped

Syntax: curl -u admin:admin -H "X-Requested-by:ambari" -i -k -X GET http://<AMBARI_IP>:8080/api/v1/clusters/<Cluster_Name>/services/KNOX

 If the component is stopped the state will be INSTALLED ("state" : "INSTALLED") in the output.


[root@bdavm621 nisan]# curl -u admin:admin -H "X-Requested-by:ambari" -i -k -X GET http://bdavm621.com:8080/api/v1/clusters/BI_41/services/KNOX
HTTP/1.1 200 OK
User: admin
Set-Cookie: AMBARISESSIONID=1x0zxckld3asbozro4jmw6c55;Path=/;HttpOnly
Expires: Thu, 01 Jan 1970 00:00:00 GMT
Content-Type: text/plain
Vary: Accept-Encoding, User-Agent
Content-Length: 1039
Server: Jetty(8.1.17.v20150415)

{
  "href" : "http://bdavm621.com:8080/api/v1/clusters/BI_41/services/KNOX",
  "ServiceInfo" : {
    "cluster_name" : "BI_41",
    "maintenance_state" : "OFF",
    "service_name" : "KNOX",
    "state" : "INSTALLED"
  },
  "alerts_summary" : {
    "CRITICAL" : 1,
    "MAINTENANCE" : 0,
    "OK" : 0,
    "UNKNOWN" : 0,
    "WARNING" : 0
  },
  "alerts" : [
    {
      "href" : "http://bdavm621.com:8080/api/v1/clusters/BI_41/services/KNOX/alerts/251",
      "Alert" : {
        "cluster_name" : "BI_41",
        "definition_id" : 101,
        "definition_name" : "knox_gateway_process",
        "host_name" : "bdavm621.com",
        "id" : 251,
        "service_name" : "KNOX"
      }
    }
  ],
  "components" : [
    {
      "href" : "http://bdavm621.com:8080/api/v1/clusters/BI_41/services/KNOX/components/KNOX_GATEWAY",
      "ServiceComponentInfo" : {
        "cluster_name" : "BI_41",
        "component_name" : "KNOX_GATEWAY",
        "service_name" : "KNOX"
      }
    }
  ],
  "artifacts" : [ ]
}[root@bdavm621 nisan]#

3) Remove KNOX

Take the backup of the knox config files under /etc/knox/conf.

Ensure all the repo files under /etc/yum.repos.d able to access the corresponding repository. Check the repository is pointing to KNOX setup. If you are using the local mirror repository then you need to start the HTTP Server ( by apachectl start ). This will ensure after you remove the KNOX, you able to install the KNOX.

If all the above prerequisite is met, remove the knoxusing below command.

Syntax: curl -u admin:admin -H "X-Requested-By: ambari" -X DELETE http://<AMBARI_IP>:8080/api/v1/clusters/<Cluster_Name>/services/KNOX

[root@bdavm621 nisan]# curl -u admin:admin -H "X-Requested-By: ambari" -X DELETE http://bdavm621.com:8080/api/v1/clusters/BI_41/services/KNOX
[root@bdavm621 nisan]#

Login to Amabri UI to confirm KNOX is removed from the UI.

3) Remove KNOX RPM's

Login to node where KNOX installed and remove the knox rpm's.

You can use any of the below commands to search the KNOX RPM's.

Syntax for searching rpm's:
yum list installed | grep knox
rpm -qa knox*
yum list installed | grep @ <repoName>

[root@bdavm621 nisan]# yum list installed | grep knox
knox_4_1_0_0.noarch                        0.6.0_TEST_23.4.1.0.0-3.el6  @TEST-4.1



Syntax to remove rpm's : yum remove <rpm_Name>

[root@bdavm621 nisan]# yum remove knox_4_1_0_0.noarch

Run the clean all command :

[root@bdavm621 nisan]# yum clean all

4) Install KNOX from Ambari UI

Re-Login to Amabri UI --> Actions --> Add Services Wizard, select KNOX and install the service again.

Thus, we are able to reinstall the KNOX. You can try similar steps to reinstall other services in Amabri.