vStream Configuration
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vStream Distributed Coordination Server/Client Services
+++++++++++++++++++++++++++++++++++++++++++++++++++++++

vStream provides an distributed configuration service, synchronization service, and naming registry for large distributed systems. 

It is required to configure three zookeeper installations. Perform the following steps on each server.

1. Edit the zookeeper configuration file.

``user@host#: vi /etc/zookeeper/zoo.cfg``

2. Append the following at the bottom of the file. (Using IP address or Hostname)

.. code::

    server.1=<Server1.IP.Adress>:2888:3888
    server.2=<Server2.IP.Adress>:2888:3888
    server.3=<Server3.IP.Adress>:2888:3888

3. Set the server id. Changing the # below to 1 for server 1, 2 for server 2, and 3 for server 3.

``user@host#: echo # > /var/lib/zookeeper/data/myid``

4. Start the zookeeper service.

``user@host#: service zookeeper start``

.. note::
    ``user@host#: tail -F /var/log/zookeeper/zookeeper.log``  to ensure zookeeper is running as expected.


vStream Distributed Commit Log Service
++++++++++++++++++++++++++++++++++++++

vStream is publish-subscribe messaging rethought as a distributed commit log. 

It is required to configure kafka on each data tier server.

1. Edit the kafka configuration file.

``user@host#: vi /opt/kafka/config/server.properties``

2. Find and change the following items. 

Find and change the broker id to a unique number starting from 0.

``broker.id=0``

Find and change the logs directory. 

``log.dirs=/data/vstream-logs-data01``

Find and change the zookeeper connection string. Replacing the Server with correct IP address or Hostname from the zookeeper configuration steps above.

``zookeeper.connect=<Server1.IP.Adress>:2181,<Server2.IP.Adress>:2181,<Server3.IP.Adress>:2181``


3. Make the logs directory and set the correct ownership.


``user@host#: mkdir /data/vstream-logs-data01``

``user@host#: chown -R kafka:kafka /data/vstream-logs-data01``

4. Start the kafka service.

``user@host#: service kafka start``

5. Repeat steps 1 through 4 for each data tier server. 

.. note::
    ``user@host#: tail -F /var/log/kafka/server.out`` to ensure kafka is running as expected.