ranger installation failed while DB connection checking

[#1]

image1.png image2.png ranger-logs.txt

While doing the installation of ranger from ambari UI , pre-requisites are checked successfully and while checking the MySQL db connection , we are facing error of service unavailable.

Kindly find the attached files & logs.

please do the needful if possible. @Kuldeep Kulkarni

[#2 · Accepted solution]

@hardik desai

Can you please verify connectivity between Ranger admin and Ambari server host?

Telnet from Ranger Admin host to Ambari Server on 8080?

503 error code - looks like Ambari Server is too busy to respond or there is network issue between Ranger Admin and Ambari Server.

Can you manually copy DBConnectionVerification.jar from ambari-server to ambari-agent on ranger admin host and restart ambari-agent followed by retry DB connection.

On Ambari-server DBConnectionVerification.jar should present at below location

/var/lib/ambari-server/resources/DBConnectionVerification.jar

On Ambari-agent, copy DBConnectionVerification.jar at below location

/usr/lib/ambari-agent/DBConnectionVerification.jar
/var/lib/ambari-agent/tmp/DBConnectionVerification.jar
/var/lib/ambari-agent/cache/DBConnectionVerification.jar

You can also try to bounce Ambari Server and see if it helps.

Please keep us posted.

Thanks @Sagar Shimpi

[#3]

@hardik desai - Please check updated answer above ^^

[#4]

@Kuldeep KulkarniKuldeep

Seems to be a connection pooling issue, Restarted multiple times ambari-agent on the slaves and event the ambari-server and it worked.

I think there needs to be a sequence first ambari-server and then ambari-agent.

Really thanks for pointing it out.

Regards

[#5]

Kuldeep Kulkarni,

Thanks for the info; we have tried doing the same but the issue still persist.

root@server:~# cksum /var/lib/ambari-server/resources/DBConnectionVerification.jar

2699944268 1931 /var/lib/ambari-server/resources/DBConnectionVerification.jar

root@slave1:~# cksum /usr/lib/ambari-agent/DBConnectionVerification.jar

2699944268 1931 /usr/lib/ambari-agent/DBConnectionVerification.jar

Best Regards,

[#6]

@Kuldeep Kulkarni

We did the things mentioned, but still the error is the same.

Also bounced the ambari-server as well as ambari-agent but things seems to be same.

Regards

[#7]

@hardik desai / @Harshit Shah

Take backup of below file --> edit it on ranger admin host --> restart ambari-agent and try again

#Backup

cp /var/lib/ambari-agent/cache/custom_actions/scripts/check_host.py /var/lib/ambari-agent/cache/custom_actions/scripts/check_host.py.bak

#Edit

vi /var/lib/ambari-agent/cache/custom_actions/scripts/check_host.py

#Comment below code

# download DBConnectionVerification.jar from ambari-server resources
   try:
     download_file(check_db_connection_url, check_db_connection_path)
   except Exception, e:
     message = "Error downloading DBConnectionVerification.jar from Ambari Server resources. Check network access to " \
               "Ambari Server.\n" + str(e)
     print message
     db_connection_check_structured_output = {"exit_code" : 1, "message": message}
     return db_connection_check_structured_output

#Save and restart ambari agent

Let me know the results.

This is hacky approach and I would not recommend it for Production clusters. We need to investigate what's happening. If you have support subscription, please open a support case with us 🙂