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  • #31
    ty Peter i try it

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    • #32
      Hi, guys.
      Question 1: why when I rejoin node, node id+1? If I have hostcount=2, my node id =0,1. When I kill node 1 and rejoin her why her id is 2?

      voltdb@ubuntu:~$ voltdb rejoin -H 192.168.1.1:3021 -d deployment.xml --admin=2332 --client=4322 --http=8086 --internal=5021 --zookeeper=45356 --replication=6655
      Initializing VoltDB...
      Build: 5.4 voltdb-5.4-0-g4a2c380-local Enterprise Edition
      Connecting to the VoltDB cluster leader /192.168.1.1:3021
      WARN: Clock skew is 28 which is high. Ideally it should be sub-millisecond. Make sure NTP is running.
      WARN: Clock skew is 28 which is high. Ideally it should be sub-millisecond. Make sure NTP is running.
      Host id of this node is: 2
      Initializing the database and command logs. This may take a moment...
      ERROR: JMX service unable to bind to port 9090
      Server completed initialization.
      Node rejoin completed

      Question 2: how I understand k-safety. Kfactor is how many copies of database we have.
      Example: hostcount=8,sitesperhsot=4,kfactor=1. Result I have 2 copies of database with 16 partition.
      Look at this screen:
      cluster.JPG
      On this screen if k factor=1 I have two copies database with 3 partition per each. When only 1 node die cluster alive.
      If kfactor=2 I have 3 copies database with 2 partition per each. When 2 nodes die cluster alive. Right?

      Go next.
      How it works with add nodes?
      Look at this screen:
      add.jpg
      I have cluster with 2 nodes. Kfactor=1 and sitesperhost=2.
      I wanna add node 3. Why cluster wait one more node. Why he cant regroup database with 3 nodes and 2 copies database with 3 partition per each how on 1st screen?
      When I add 4 node, join completed and I have 4 nodes with 2 copies database with 4 partition per each.
      Last edited by Ilia; 08-12-2015, 05:32 AM.

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      • #33
        Ilia,

        Question 1: why when I rejoin node, node id+1? If I have hostcount=2, my node id =0,1. When I kill node 1 and rejoin her why her id is 2?
        VoltDB keeps track of every instance that attempts to connect to the cluster with an internal logical id, which can be used to understand node/cluster failures. This does not affect usability.

        How it works with add nodes?
        There's a chapter on availability which will explain how Ksafety works and adding nodes with elastic scaling.

        I wanna add node 3. Why cluster wait one more node. Why he cant regroup database with 3 nodes and 2 copies database with 3 partition per each how on 1st screen?
        In the documentation linked above, it states "You must add a sufficient number of nodes to create an integral K-safe unit. That is, K+1 nodes.". So in your case, you'll need to add 2 nodes.

        Peter Zhao

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        • #34
          Hi every one!

          Tell me please, VoltDB Management Center is completely excluded from the Enterprise Version and will no longer be developed? Is there another alternative VoltDB Management Center?

          Important
          The VoltDB Enterprise Manager is deprecated. It is supported for existing customers but is not recommended for new deployments and will be removed in a future release. The VoltDB Management Center, which has improved and extended management and monitoring capabilities built directly into the VoltDB database server, is the recommended replacement for the Enterprise Manager. See the Administrator's Guide for more information on the VoltDB Management Center.

          https://docs.voltdb.com/ReleaseNotes/

          Thank you in advance

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          • #35
            Hi Ilia,

            The VEM (VoltDB Enterprise Manager) tool was deprecated in v5.0 and removed in v6.0. In v5.0 VEM was replaced with VMC, the VoltDB Management Center. It's here to stay, and is part of both the Community and Enterprise kits.

            John

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            • #36
              Hi John

              One more question,
              It turns VoltDB Management Center is available as a single product? And installs separate package?

              Thank you in advance

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              • #37
                The VoltDB Management Center is part of the VoltDB kit. Essentially it is a web application hosted by each node of the VoltDB cluster. You can point your browser to any node and manage/monitor the database.

                John

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