Couchbase provides high availability and disaster recovery in several ways:
- Homogenous cluster
- Replication
- Backup and restore
- Rack zone awareness
This blog will show how to create a Couchbase cluster using Couchbase Command Line Interface (CLI). In addition, these steps can also be performed using the Couchbase REST API and the Couchbase Web Console.
Couchbase nodes in a cluster are homogeneous. Applications can write to any node and read from any node. There is no write-to-master and read-from-slave architecture that inherently gives you scalability problems. This allows the Couchbase cluster to truly scale horizontally to meet your growing application demands.
Creating a Couchbase cluster involves the following steps:
- Provision Couchbase: Provision 1 or more Couchbase nodes, say on Amazon Web Services
- Initialize master: Initialize any node to be the “master” of the cluster by calling
cluster-initCLI command - Create cluster: For all other nodes, create a cluster by invoking the
server-addCLI command - Rebalance cluster: Finally, rebalance the cluster by calling the
rebalanceCLI command
Provision Couchbase
Provision a Couchbase node on Amazon:
1 2 3 4 5 6 | aws ec2 run-instances \--image-id ami-db95ffbb \--count 1 \--instance-type m3.large \--key-name my-couchbase-key \--security-groups "Couchbase Server Community Edition-4-0-0-AutogenByAWSMP-" |
Security group name is explained in Couchbase Cluster on Amazon using CLI.
Let’s call this node as “master”.
Initialize Couchbase “master”
Configure the “master” instance and initialize the cluster:
01 02 03 04 05 06 07 08 09 10 11 | export COUCHBASE_CLI=/Users/arungupta/tools/Couchbase-Server-4.0.app/Contents/Resources/couchbase-core/bin/couchbase-cli$COUCHBASE_CLI \ cluster-init \ -c <master-ip>:8091 \ -u Administrator \ -p password \ --cluster-username Administrator \ --cluster-password password \ --cluster-index-ramsize=300 \ --cluster-ramsize=300 \ --services=data,index,query |
Create another instance, lets call it “worker”. Note, this is not a master/slave architecture. Couchbase cluster is homogenous where any node in the cluster can be “master”.
Create Couchbase Cluster
Add this newly created “worker” instance to the cluster:
1 2 3 4 5 6 7 8 | $COUCHBASE_CLI \ server-add \ --cluster=<master-ip>:8091 \ --user Administrator \ --password password \ --server-add=<worker-ip> \ --server-add-username=Administrator \ --server-add-password=password |
Typically, you’ll create and add multiple nodes to the cluster before rebalancing.
Rebalance Couchbase Cluster
Rebalance the cluster:
1 2 3 4 5 | $COUCHBASE_CLI \rebalance \--cluster=<master-ip>:8091 \--user Administrator \--password password |
Now, you can create as many instances and easy include them in the cluster.
Adding a single node and rebalancing the cluster can be easily done as a single step:
1 2 3 4 5 6 7 8 | $COUCHBASE_CLI \rebalance \--cluster=<master-ip>:8091 \--user Administrator \--password password--server-add=<worker-ip>--server-add-username=Administrator--server-add-password=password |
Now, your cluster is accessible at http://<master-ip>:8091 or http://<worker-ip>:8091.
Further references …
- Couchbase Server Developer Portal
- Hello Couchbase Example
- Couchbase CLI
- Questions on StackOverflow, Forums or Slack Channel
- Follow us @couchbasedev
- Couchbase 4.5 Beta
Enjoy!
| Reference: | Scaling and Rebalancing a Couchbase Cluster using CLI from our JCG partner Arun Gupta at the Miles to go 3.0 … blog. |
