Apache Cassandra 2019 Cluster

Apache Cassandra 2019 Cluster

Haha, it looks like continues hash to form the cluster and replica the data in nodes.

Try to Set Up Cassandra Manually
> wget http://mirrors.ibiblio.org/apache/cassandra/3.11.4/apache-cassandra-3.11.4-bin.tar.gz
Unzip and place in the working directory
> sudo ln -s /home/carl/tool/apache-cassandra-3.11.4 /opt/cassandra-3.11.4
> sudo ln -s /opt/cassandra-3.11.4 /opt/cassandra

Add the Cassandra to the Path
export PATH="/opt/cassandra/bin:$PATH"

Some important configurations in conf/cassandra.yaml
cluster_name: 'SillycatCluster'
- seeds: "ubuntu-master"
listen_address: ubuntu-master
native_transport_port: 9042
rpc_address: ubuntu-master

Command to start cassandra
> bin/cassandra -f

Check the status on ubuntu-master
> nodetool status
Datacenter: datacenter1
=======================
Status=Up/Down
|/ State=Normal/Leaving/Joining/Moving
--  Address         Load       Tokens       Owns (effective)  Host ID                               Rack
UN  192.168.56.101  103.66 KiB  256          100.0%            19b79248-63e2-4749-bf9d-5081f3d3ada0  rack1

Do the similar on ubuntu-dev2 and ubuntu-dev4
> wget http://mirrors.ibiblio.org/apache/cassandra/3.11.4/apache-cassandra-3.11.4-bin.tar.gz
Unzip and place in right directory, add to PATH

Change the conf/cassandra.yaml as follow:
cluster_name: 'SillycatCluster'
- seeds: "ubuntu-master"
listen_address: ubuntu-dev2 or listen_address: ubuntu-dev4
native_transport_port: 9042
rpc_address: ubuntu-dev2 or rpc_address: ubuntu-dev4

Start that and you can see this from ubuntu-master
> bin/cassandra -f

Check status
> nodetool status
Datacenter: datacenter1
=======================
Status=Up/Down
|/ State=Normal/Leaving/Joining/Moving
--  Address         Load       Tokens       Owns (effective)  Host ID                               Rack
UN  192.168.56.3    45.66 KiB  256          100.0%            5a91cb7e-0b4d-487a-b2bc-a5e13e26887a  rack1
UN  192.168.56.101  108.61 KiB  256          100.0%            19b79248-63e2-4749-bf9d-5081f3d3ada0  rack1

3 nodes will be like this
> nodetool status
Datacenter: datacenter1
=======================
Status=Up/Down
|/ State=Normal/Leaving/Joining/Moving
--  Address         Load       Tokens       Owns (effective)  Host ID                               Rack
UN  192.168.56.3    93.96 KiB  256          65.2%             5a91cb7e-0b4d-487a-b2bc-a5e13e26887a  rack1
UN  192.168.56.101  108.61 KiB  256          70.1%             19b79248-63e2-4749-bf9d-5081f3d3ada0  rack1
UN  192.168.56.103  26.22 KiB  256          64.7%             11aa7d21-7ce3-48dd-8921-e196feb74f42  rack1

Use my other machine to connect to the cluster
> cqlsh ubuntu-master 9042

Create the test key space
> CREATE KEYSPACE patient WITH replication = {'class': 'SimpleStrategy', 'replication_factor' : 2};

Create table to store the data
sillycat@cqlsh> CREATE TABLE patient.exam (
   ... patient_id int,
   ... id int,
   ... date timeuuid,
   ... details text,
   ... PRIMARY KEY (patient_id, id));

Insert some test data from other people’s blog
> INSERT INTO patient.exam (patient_id,id,date,details) values (1,1,now(),'first exam patient 1');
> INSERT INTO patient.exam (patient_id,id,date,details) values (1,2,now(),'second exam patient 1');
> INSERT INTO patient.exam (patient_id,id,date,details) values (2,1,now(),'first exam patient 2');
> INSERT INTO patient.exam (patient_id,id,date,details) values (3,1,now(),'first exam patient 3');

Query all the records for patient 1
> use patient;
> select * from exam where patient_id=1;

Connect to node ubuntu-dev2
> cqlsh ubuntu-dev2 9042
> desc keyspaces;
patient  system_schema  system_auth  system  system_distributed  system_traces

> use patient;

You can see the same data there with the same commands
> select * from exam where patient_id=1;

The cluster works pretty well.

Seed is the contact nodes we need when other nodes start.

References:
https://sillycat.iteye.com/blog/2011992
https://www.ibm.com/developerworks/cn/opensource/ba-set-up-apache-cassandra-architecture/index.html