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This page provides instructions to set up a Magic Collaboration Studio cluster on your system. A Magic Collaboration Studio cluster is composed of two clustering layers – Magic Collaboration Studio and Cassandra.
To set up a Magic Collaboration Studio cluster, you need to perform two separate tasks:
An illustration of Magic Collaboration Studio cluster and Cassandra cluster nodes within Magic Collaboration Studio 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 contact point.
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 contact point 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 IPs of the nodes are 10.1.1.101, 10.1.1.102, and 10.1.1.103, select one of them (e.g. 10.1.1.101) as the seed. When configuring cassandra.yaml, specify 10.1.1.101 as the contact point value for all of the three nodes.
| Machine IP | 10.1.1.101 | 10.1.1.102 | 10.1.1.103 |
|---|---|---|---|
| seeds | 10.1.1.101, 10.1.1.102 | 10.1.1.101, 10.1.1.102 | 10.1.1.101, 10.1.1.102 |
| 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 |
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.
After installing and configuring all nodes, start the seed node. Verify that it is operational by issuing the command "nodetool status".
Once the seed node is operational, you can proceed to start the other nodes in the cluster. You must allow the node to join the cluster before proceeding to the next node. After all nodes have started, the "nodetool status" command will display results as shown below.
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 256 100% b33c603a-95c7-426d-9f7b-ebad2375086a rack1 UN 10.1.1.102 6.34 GB 256 100% 16f40503-4a65-45fe-9ee7-5d942506aa87 rack1 UN 10.1.1.103 6.15 GB 256 100% 2d90c119-08a4-4799-ac73-0440215d0b18 rack1
Node Consistency
In order to ensure that all nodes are consistent, please run the "nodetool repair" command nightly. This can be scheduled as a crontab job or via Windows Task Scheduler. This only needs to be executed on a single node.
Cassandra configuration parameters
- esi.persistence.datastax-java-driver.basic.contact-points
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.
esi.persistence.datastax-java-driver {
basic {
contact-points = ["10.1.1.101:9042", "10.1.1.102:9042", "10.1.1.103:9042"]
- esi.persistence.cassandra.keyspace.replication-factor
This parameter defines the Cassandra replication factor which 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 Magic Collaboration Studio connects to Cassandra and creates a new twc 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.
Magic Collaboration Studio uses QUORUM for both write and read consistency levels.
Click here for a detailed explanation of data consistency.
Update Authentication Server parameters
Apply Cassandra configuration parameters to authserver.properties.
cassandra.contactPoints=10.1.1.101, 10.1.1.102, 10.1.1.103 cassandra.keyspace.replication.factor=3
To start up the Magic Collaboration Studio 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 Magic Collaboration Studio 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 Magic Collaboration Studio 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 Magic Collaboration Studio 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]
Setting up a Magic Collaboration Studio cluster
Before setting up a Magic Collaboration Studio cluster, you need to determine the following.
- The initial number of nodes in the cluster.
- The IP address of each Magic Collaboration Studio node.
- Prepare a list of IPs of Cassandra nodes.
The instructions below use the following sample environment for ease of understanding.
- 3 nodes Magic Collaboration Studio cluster.
- Magic Collaboration Studio 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 Magic Collaboration Studio cluster involves 2 groups of parameters in application.conf.
Magic Collaboration Studio clustering parameter
- akka.cluster.seed-nodes
This parameter indicates the initial seed for the cluster.
If you install Magic Collaboration Studio using the installer file, you will be asked to provide the seed node IP during 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:
seed-nodes = ["akka://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:
seed-nodes = ["akka://twcloud@10.1.1.111:2552","akka://twcloud@10.1.1.112:2552","akka://twcloud@10.1.1.113:2552"]
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