4. Known Issues

In this section:

  • Ambari does not support running or installing stacks on Unbuntu.

  • The component version information displayed by Ambari is based on the Ambari Stack definition. If you have applied patches to the Stack and to your software repository, that component version might differ from the actual version installed. There is no functional impact on Ambari if the patch versions mismatch. If you have any questions on component versions, refer to the rpm version installed on the actual host.

  • BUG-24234: Unable to start/stop services when using Oracle database for Ambari.

    Problem: If you are using Oracle for the Ambari DB, you can run into a scenario when performing a start all/stop all where Ambari becomes unresponsive and the following ORA error is printed to the ambari-server log:

    08:54:51,320 ERROR [qtp1280560314-2070] ReadHandler:84 - Caught a runtime exception executing a query
    Local Exception Stack: 
    Exception [EclipseLink-4002] (Eclipse Persistence Services - 2.4.0.v20120608-r11652): org.eclipse.persistence.exceptions.DatabaseException
    Internal Exception: java.sql.SQLSyntaxErrorException: ORA-01795: maximum number of expressions in a list is 1000 

    Workaround: Please upgrade to Ambari 1.6.1 and contact Hortonworks Support for a patch to apply.

  • BUG-16035: yum Fails on Free Disk Space Check

    Problem: 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

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

    diskspacecheck=0

    For more detailed instructions, see the Ambari Troubleshooting Guide.

  • BUG-16012: Ambari Agents may fail to register with Ambari Server during the “Confirm Hosts” step in the Cluster Install wizard when deploying HDP using Ambari 1.4.x or later on RHEL CentOS 6.5.

    Problem: Agent logs show the following log entry, indicating 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 .

    Workaround: Upgrade the RHEL OpenSSL library to version 1.0.1 build 16. For more detailed instructions, see the Ambari Troubleshooting Guide.

  • BUG-15604: Ganglia restart fails to start Ganglia Monitor (gmond) on the first restart after upgrade to 1.5.0.

    Problem: After upgrading Ambari from version 1.4.x to 1.5.0, the configuration files for the Ganglia Monitors (gmond-s) running on Ganglia Server (gmetad) are generated when Ganglia Server is started. This causes the monitor restart to fail if Ganglia Server is started after Ganglia Monitors, which in this case is the custom restart command.

    Workaround: After upgrading Ambari 1.4.x to 1.5.0, restart Ganglia Server, twice if necessary.

  • BUG-15584: Nagios service does not appear as a service that requires a restart if you change ports on services that it monitors.

    Problem: STR (Example for MR2): Change mapreduce.jobhistory.webapp.address port. Restart all component (services) that have "restart icon". Important: Nagios does not display a "restart icon". Actual result: If Nagios did not restart, incorrect alerts would be displayed. Expected result: Nagios has "restart icon". Or, Nagios restarts automatically.

    Workaround: Restart Nagios using the Ambari Web UI if you change any ports for any services.

  • BUG-15516: MapReduce Service check fails on HDP 1.3.3 cluster with components assigned to non-default hosts.

    Problem: When installing Ambari 1.5.0 and using HDP 1.3.3, adding a MapReduce client on a host where no HDFS Client exists may cause service check failures. This issue does not occur when upgrading to Ambari 1.5.0 on HDP 1.3.3.

    Workaround: Add HDFS_CLIENT on the host where the service check fails.

  • BUG-15195: A significant time lag occurs before Restart Indicators disappear after restarting.

    Problem: Delays of up to a minute are possible, depending on cluster size.

    Workaround: Wait thirty seconds, then refresh your browser.

  • BUG-14475: Adding client components using Ambari does not work in a secure cluster.

    Problem: In a RHEL 6/HDP 1.3.3/Ambari 1.4.4 secure cluster, customers cannot add webHCAT and other clients to an existing host. This prevents some featuures from working properly.

    Workaround: No workaround for Ambari 1.5.0. Fixed and being tested for Ambari 1.5.1 release.