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HDP on Linux – Installation Forum

Ambari Server unknown_ca

  • #25702
    Dan Gentry

    Trying to get a test instance running.

    Ambari-server install goes well, until:

    1:42:24,430 INFO AmbariServer:323 – ********* Current Clusters State *********
    11:42:24,430 INFO AmbariServer:324 – Clusters=[ ]
    11:42:24,430 INFO AmbariServer:326 – ********* Initializing ActionManager **********
    11:42:24,430 INFO AmbariServer:328 – ********* Initializing Controller **********
    11:42:24,434 INFO AmbariManagementControllerImpl:166 – Initializing the AmbariManagementControllerImpl
    11:42:24,436 INFO Server:266 – jetty-7.6.7.v20120910
    11:42:24,472 INFO ContextHandler:744 – started o.e.j.s.ServletContextHandler{/,file:/usr/lib/ambari-server/web/}
    11:42:26,461 INFO AbstractConnector:338 – Started SelectChannelConnector@
    11:42:26,463 INFO Server:266 – jetty-7.6.7.v20120910
    11:42:26,464 INFO ContextHandler:744 – started o.e.j.s.ServletContextHandler{/,null}
    11:42:27,285 INFO SslContextFactory:300 – Enabled Protocols [SSLv2Hello, SSLv3, TLSv1] of [SSLv2Hello, SSLv3, TLSv1]
    11:42:27,287 INFO AbstractConnector:338 – Started SslSelectChannelConnector@
    11:42:27,315 INFO SslContextFactory:300 – Enabled Protocols [SSLv2Hello, SSLv3, TLSv1] of [SSLv2Hello, SSLv3, TLSv1]
    11:42:27,316 INFO AbstractConnector:338 – Started SslSelectChannelConnector@
    11:42:27,316 INFO AmbariServer:343 – ********* Started Server **********
    11:42:27,316 INFO ActionManager:64 – Starting scheduler thread
    11:42:27,317 INFO AmbariServer:346 – ********* Started ActionManager **********
    11:42:36,108 WARN nio:651 – Received fatal alert: unknown_ca
    11:42:37,661 WARN nio:651 – Received fatal alert: unknown_ca

    Hostnames are in /etc/hosts, and ntp is running. Times are sync’d. IPTables are turned off on all the nodes. When I try to install nodes using ambari , every node fails to register. Help


  • Author
  • #25732

    Hi Dan,

    A couple of things to check, you may have already, but you didn’t mention them so:

    1- Make sure that SELinux is disabled.
    2- make sure that you have passwordless ssh set up from the ambari server node to all other nodes.


    Dan Gentry


    Thanks. I should have included those points in the first mail:

    “getenforce” on each node returns “Disabled”. /etc/selinux/config shows disabled as well.

    Passwordless ssh from the ambari node to each other node works fine.


    Seth Lyubich

    Hi Dan,

    Can you please try to run “ambari-server reset” and try again?

    Hope this helps.



    I have a 5 nodes cluster on which HDP 2.0 CP is installed. There are on Amazon EC2. But there is no proper GUI to see the hadoop NNs & DNs and there is a need to monitor them. I proposed we should use Ambari to get a GUI.

    Now, when I was given the task, i installed Ambari server on NN(Master), did password-less SSH, temporarily disable SELINUX(setenforce 0) etc.. Now I am able to ssh to other nodes without a password. But when I am trying to register the other nodes, to automatically install ambari-agent, I am always getting error “Registration to the server failed” & getting a frequent warning “WARN nio:651 – Received fatal alert: unknown_ca”. Please help me. I have been trying since yesterday.

    Is it that we cannot install Ambari on top of HDP 2.0 CP to get a GUI? Am i on the wrong track?


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