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To set up a TWCloud Cluster, you need to

perform two separate tasks:

1. Set up a Cassandra Cluster
2. Set up a TWCloud Cluster

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An illustration of TWCloud Cluster and Cassandra Cluster nodes within TWCloud Cluster.

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cassandra cassandra

Setting up a Cassandra Cluster

Prior to establishing a Cassandra cluster, you need to determine the following.

• The initial number of nodes in the cluster.
• The IP address of each node.
• Determine which node

• will be the seed.

When setting up a Cassandra node, you need to configure a seed that indicates an initial contact point for the new node. So, you can configure the seed using the IP of any existing active node in the cluster. Use the node's own IP when configuring the first node. For example, if you are configuring a three-node cluster and the nodes' IPs

are 10.1.1.101, 10.1.1.102,

 and 10.1.1.103. Select one, for

example 10.1.1.101, as

the seed. While you are

configuring cassandra.yaml,

specify 10.1.1.101

 as the seed value for all of the three nodes.

Now that you understand what a seed is and how to configure it, follow the instructions to install and configure Cassandra on Windows or Linux Operating System. 

• Windows instructions
• Linux instructions

Please note that listen_

address and broadcast_rpc_address are still their machine.

After installing and configuring all nodes, start the seed node machine and verify that it is up and running first, and then start the rest of the nodes. You can check cluster status

using the command

"nodetool status".

Datacenter: datacenter1

     rack1

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twcloud twcloud

Setting up a TWCloud Cluster

Before setting up a TWCloud Cluster, you need to determine the following.

• The initial number of nodes in the cluster.
• The IP address of each TWC node.

• Prepare a list of

• IP addresses of the Cassandra nodes.

The instructions below use the following sample environment for ease of understanding.

• 3

• node TWC cluster.

• TWC node IP

• addresses are 10.1.1.111, 10.1.1.112, and 10.1.1.113

• .
• All nodes will be used as seed

• nodes.
• IP

• addresses of Cassandra nodes are 10.1.1.101, 10.1.1.102, 10.1.1.103.

Setting up the TWCloud Cluster involves 2 groups of parameters

in application.conf.

1. TWCloud clustering parameter
   

   - akka.cluster.seed-nodes

   This parameter indicates the initial contact points for the cluster.

   If you install TWCloud using the installer file, you will be asked to provide the seed node IP during the installation process and the value will be configured

1. in application.conf.

   If you install using the zip file, you will need to manually configure the parameter in application.conf. Search for the following.

   Code Block
   title application.conf

1. seed-nodes = ["akka.tcp://twcloud@${seed-node.ip}:2552"]

1.  Replace ${seed-node.ip}

1.  with the IP addresses of the seed

1. nodes, so it should look similar to the following.

   Code Block
   title application.conf

1. seed-nodes = ["akka.tcp://twcloud@10.1.1.111:2552","akka.tcp://twcloud@10.1.1.112:2552","akka.tcp://twcloud@10.1.1.113:2552"]

2. Cassandra configuration parameters 

  - esi.persistence.cassandra.connection.seeds

          The value of this parameter is a list of Cassandra node IP addresses. You can find this parameter

in application.

conf by looking for the following.

# List of comma delimited host.

# Ex. seeds = ["10.1.1.123", "10.1.1.124", "10.1.1.125"]

- seeds

=

["localhost"]

As you can see, the default value

is [“localhost”], which is only suitable for a single node server where both TWCloud and Cassandra are deployed on the same machine. According to our sample environment, you should change it to the following.

["10.1.1.101", "10.1.1.102", "10.1.1.103"]

- esi.persistence.cassandra.keyspace.replication-factor

This parameter defines the Cassandra replication factor for the “esi” keyspace used by TWCloud. The replication factor describes how many copies of your data will be written by Cassandra. For example, replication factor 2 means your data will be written to 2 nodes.

For a three-node cluster, if you would like the cluster to be able to survive 1 node loss, you will need to set the replication factor to 3.

persistence {

         cassandra {
                 keyspace {                                                                                           
                        replication-factor = 3                                         
                 }

Please note that this configuration will be used only for the first time TWCloud connects to Cassandra and creates a new "esi" keyspace. Changing the replication factor after the keyspace has already been created is rather a complex task.

Read this document

 if you need to change it.

Click here

 for a detailed explanation

of data consistency.

To start up the TWCloud cluster,

start the server on the seed machine and wait until you see a message similar to the following in the server.log. 

INFO  2017-02-15 10:57:08.409 TWCloud Cluster with 1 node(s) : [10.1.1.111] [com.nomagic.esi.server.core.actor.ClusterHealthActor, twcloud-esi.actor.other-dispatcher-31]

Then you can start the server on the remaining machines. You should see the following messages in the server.log which shows all 3 nodes are forming the cluster.

Related pages:

• Installing and configuring Cassandra on Windows
• Installing and configuring Cassandra on Linux