2. Resolving Ambari Installer Problems

Try the recommended solution for each of the following problems:

 2.1. Problem: Browser crashed before Install Wizard completes

Your browser crashes or you accidently close your browser before the Install Wizard completes.

 2.1.1. Solution

The response to a browser closure depends on where you are in the process:

  • The browser closes prior to hitting the Deploy button.

    Re-launch the same browser and continue the install process. Using a different browser forces you to re-start the entire process.

  • The browser closes after the Deploy button has launched the Install, Start, and Test screen.

    Re-launch the same browser and continue the process or use a different browser and re-login. You are returned to the Install, Start, and Test screen.

 2.2. Problem: Install Wizard reports that the cluster install has failed

The Install, Start, and Test screen reports that the cluster install has failed.

 2.2.1. Solution

The response to a report of install failure depends on the cause of the failure:

  • The failure is due to intermittent network connection errors during software package installs.

    Use the Retry button on the Install, Start, and Test screen.

  • The failure is due to misconfiguration or other setup errors.

    1. Use the left nav bar to go back to the appropriate screen; for example, Customize Services.

    2. Make your changes.

    3. Continue in the normal way.

  • The failure occurs during the start/test sequence.

    1. Click Next and Complete and proceed to the Monitoring Dashboard.

    2. Use the Services View to make your changes.

    3. Re-start the service using the Mangement Header.

  • The failure is due to something else.

    1. Open an SSH connection to the Ambari Server host.

    2. Clear the database. At the command line, type:

       ambari-server reset 
    3. Clear your browser cache.

    4. Re-run the Install Wizard.

 2.3. Problem: Ambari Agents May Fail to Register with Ambari Server.

When deploying HDP using Ambari 1.4.x or later on RHEL CentOS 6.5, click the “Failed” link on the Confirm Hosts page in the Cluster Install wizard to display the Agent logs. The following log entry indicates the SSL connection between the Agent and Server failed during registration:

INFO 2014-04-02 04:25:22,669 NetUtil.py:55 - Failed to connect to https://{ambari-server}:8440/cert/ca due to [Errno 1] _ssl.c:492: error:100AE081:elliptic curve routines:EC_GROUP_new_by_curve_name:unknown group

For more detailed information about this OpenSSL issue, see https://bugzilla.redhat.com/show_bug.cgi?id=1025598

 2.3.1. Solution:

In certain recent Linux distributions (like RHEL/Centos/Oracle Linux 6.x), the default value of nproc is lower than the value required if you are deploying the HBase service. To change this value:

  1. Check the OpenSSL library version installed on your host(s):

    rpm -qa | grep
    openssl openssl-1.0.1e-15.el6.x86_64
  2. If the output reads openssl-1.0.1e-15.x86_64 (1.0.1 build 15) you must upgrade the OpenSSL library by running the following command:

    yum upgrade openssl
  3. Verify you have the newer version of OpenSSL (1.0.1 build 16):

    rpm -qa  | grep openssl
  4. Restart Ambari Agent(s) and Click “Retry Failed” on the Wizard.

 2.4. Problem: The “yum install ambari-server” Command Fails

You are unable to get the initial install command to run.

 2.4.1. Solution:

You may have incompatible versions of some software components in your environment. Check the Minimum System Requirements and make any necessary changes.

 2.5. Problem: HDFS Smoke Test Fails

If your DataNodes are incorrectly configured, the smoke tests fail and you get this error message in the DataNode logs:


 2.5.1. Solution:

  • Make sure that reverse DNS look-up is properly configured for all nodes in your cluster.

  • Make sure you have the correct FQDNs when specifying the hosts for your cluster. Do not use IP addresses - they are not supported.

Restart the installation process.

 2.6. Problem: yum Fails on Free Disk Space Check

If you boot your Hadoop DataNodes with/as a ramdisk, you must disable the free space check for yum before doing the install. If you do not disable the free space check, yum will fail with the following error:

Fail: Execution of '/usr/bin/yum -d 0 -e 0 -y install unzip' returned 1. Error Downloading Packages: unzip-6.0-1.el6.x86_64: Insufficient space in download directory /var/cache/yum/x86_64/6/base/packages
    * free   0
    * needed 149 k

 2.6.1. Solution:

To disable free space check, update the DataNode image with a directive in /etc/yum.conf:


 2.7. Problem: The HCatalog Daemon Metastore Smoke Test Fails

If the HCatalog smoke test fails, this is displayed in your console:

Metastore startup failed, see /var/log/hcatalog/hcat.err

 2.7.1. Solution:

  1. Log into the HCatalog node in your cluster.

  2. Open /var/log/hcatalog/hcat.err or /var/log/hive/hive.log  (one of the two will exist depending on the installation) with a text editor.

  3. In the file, see if there is a MySQL Unknown Host Exception like this:

    at java.lang.reflect.Method.invoke (Method.java:597)
    at org.apache.hadoop.util.Runjar.main (runjar.java:156)
    Caused by: java.net.UnknownHostException:mysql.host.com

    This exception can be thrown if you are using a previously existing MySQL instance and you have incorrectly identified the hostname during the installation process. When you do the reinstall, make sure this name is correct.

  4. In the file, see if there is an ERROR Failed initializing database entry like this:

    11/12/29 20:52:04 ERROR DataNucleus.Plugin: Bundle
    org.eclipse.jdt.core required
    11/12/29 20:52:04 ERROR DataStore.Schema: Failed initialising

    This exception can be thrown if you are using a previously existing MySQL instance and you have incorrectly identified the username/password during the installation process. It can also occur when the user you specify does not have adequate privileges on the data­base. When you do the reinstall, make sure this username/password is correct and that the user has adequate privilege.

  5. Restart the installation process.

 2.8. Problem: A service with a customized service user is not appearing properly in Ambari Web

You are unable to monitor or manage a service in Ambari Web when you have created a customized service user name with a hyphen, for example, hdfs-user.

 2.8.1. Solution

Hyphenated service user names are not supported. You must re-run the Ambari Install Wizard and create a different name.

loading table of contents...