Fixing blank charts on ambari home page (Hortonworks Data Platform)

I created a 4 node container based (Proxmox LXC) Hortonworks Data Platform 2.5 Hadoop cluster recently and all went well apart from all the charts on the Ambari homepage were blank or showing “N/A”, like this:

An outline of the environment:

  • 4 node cluster of LXC containers on Proxmox host
  • Centos 7 Linux OS
  • Nodes are called bishdp0[1-4], all created from same template and identical configuration
  • All containers are on 192.168.1.0/24 network
  • DNS Server also available on same network and all hosts can resolve each other via DNS
  • Hortonworks Data Platform version 2.5
  • Proxmox host sits on a corporate network and the host has iptables set to allow the containers on 192.168.1.0/24 to reach the internet via the corporate proxy server, e.g. for yum access
  • Other than the blank charts everything appears to be working fine

After much reading around it turns out that I hadn’t quite set up the proxy serving correctly, specifically that I hadn’t told Ambari to ignore some hosts, namely the bishdp0[1-4] hosts on the 192.168.1.0/24 network, when proxying. I can’t find a 2.5 HDP version of the document for setting up the proxy serving for Ambari but the 2.2 instructions worked.

Steps I took to fix the problem:

First stop the services on the cluster. Log on to the node with the Ambari Server where I have a script called ambari-stop-all-services.sh which I created based on part of this article. Thanks slm.

Run the script:

./ambari-stop-all-services.sh

Now stop the Ambari agent on all the servers:

pdsh -w bishdp0[1-4] service ambari-agent stop

Now stop the Ambari Server:

service ambari-server stop

Now edit the Ambari environment script:

vi /var/lib/ambari-server/ambari-env.sh

Look for the line that begins “export AMBARI_JVM_ARGS” and ensure it has entries for the following parameters:

  • http.proxyHost
  • http.proxyPort
  • http.proxyUser
  • http.proxyPassword
  • http.nonProxyHosts

It’s the last one that was missing in my case, which meant that Ambari was trying to go to the proxy server even for these containers on the 192.168.1.0/24 network.

After editing, the line looked like this (I’ve redacted the specifics – just replace the entries with values suited to your environment):

export AMBARI_JVM_ARGS=$AMBARI_JVM_ARGS’ -Xms512m -Xmx2048m -XX:MaxPermSize=128m -Dhttp.proxyHost=<proxy IP> -Dhttp.proxyPort=<proxy port> -Dhttp.proxyUser=<user> -Dhttp.proxyPassword=<password> -Dhttp.nonProxyHosts=<*.domain> -Djava.security.auth.login.config=$ROOT/etc/ambari-server/conf/krb5JAASLogin.conf -Djava.security.krb5.conf=/etc/krb5.conf -Djavax.security.auth.useSubjectCredsOnly=false’

Now restart everything, Ambari server first:

service ambari-server start

…then the agents on all nodes (pdsh is great – thanks Robin Moffatt for your notes!)

pdsh -w bishdp0[1-4] service ambari-agent start

And finally start the services on the cluster using the ambari-start-all-services.sh script.

./ambari-start-all-services.sh

After I did this, the charts started showing details: