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This page provides instructions to set up a Teamwork Cloud (TWCloud) Cluster on your system. A TWCloud Cluster is composed of two clustering layers, TWCloud and Cassandra.
To set up a TWCloud Cluster, you need to perform two separate tasks:
An illustration of TWCloud Cluster and Cassandra Cluster nodes within TWCloud Cluster.
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.
Please note that listen_address and broadcast_rpc_address are still their machine.
| Machine IP | 10.1.1.101 | 10.1.1.102 | 10.1.1.103 |
|---|---|---|---|
| seeds | 10.1.1.101 | 10.1.1.101 | 10.1.1.101 |
| listen_address | 10.1.1.101 | 10.1.1.102 | 10.1.1.103 |
| broadcast_rpc_address | 10.1.1.101 | 10.1.1.102 | 10.1.1.103 |
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 ======================= Status=Up/Down |/ State=Normal/Leaving/Joining/Moving -- Address Load Tokens Owns (effective) Host ID Rack UN 10.1.1.101 6.7 GB 256 35.1% b33c603a-95c7-426d-9f7b-ebad2375086a rack1 UN 10.1.1.102 6.34 GB 256 32.5% 16f40503-4a65-45fe-9ee7-5d942506aa87 rack1 UN 10.1.1.103 6.15 GB 256 32.4% 2d90c119-08a4-4799-ac73-0440215d0b18 rack1
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.
- 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 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.
application.confseed-nodes = ["akka.tcp://twcloud@${seed-node.ip}:2552"]Replace ${seed-node.ip} with the IP addresses of the seed nodes, so it should look similar to the following.
application.confseed-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. # Setting the value as localhost will be resolved from InetAddress.getLocalHost().getHostAddress() # 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.
seeds = ["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.
TWCloud uses QUORUM for both write and read consistency levels.
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.
INFO 2017-02-15 10:58:23.956 TWCloud Cluster with 2 node(s) : [10.1.1.111, 10.1.1.112] [com.nomagic.esi.server.core.actor.ClusterHealthActor, twcloud-esi.actor.other-dispatcher-18] INFO 2017-02-15 10:58:25.963 TWCloud Cluster with 3 node(s) : [10.1.1.111, 10.1.1.112, 10.1.1.113] [com.nomagic.esi.server.core.actor .ClusterHealthActor, twcloud-esi.actor.other-dispatcher-18]