Cassandra Quickstart
STEP 1: GET CASSANDRA USING DOCKER
You’ll need to have Docker Desktop for Mac, Docker Desktop for Windows, or similar software installed on your computer.
Apache Cassandra is also available as a tarball or package download.
docker pull cassandra:latest
STEP 2: START CASSANDRA
A Docker network allows us to access the container’s ports without exposing them on the host.
docker network create cassandra
docker run --rm -d --name cassandra --hostname cassandra --network cassandra cassandra
STEP 3: CREATE FILES
The Cassandra Query Language (CQL) is very similar to SQL but suited for the JOINless structure of Cassandra.
Create a file named data.cql and paste the following CQL script in it. This script will create a keyspace, the layer at which Cassandra replicates its data, a table to hold the data, and insert some data into that table:
CREATE KEYSPACE IF NOT EXISTS store WITH REPLICATION =
{ 'class' : 'SimpleStrategy',
'replication_factor' : '1'
};
CREATE TABLE IF NOT EXISTS store.shopping_cart (
userid text PRIMARY KEY,
item_count int,
last_update_timestamp timestamp
);
INSERT INTO store.shopping_cart
(userid, item_count, last_update_timestamp)
VALUES ('9876', 2, toTimeStamp(now()));
INSERT INTO store.shopping_cart
(userid, item_count, last_update_timestamp)
VALUES ('1234', 5, toTimeStamp(now()));
STEP 4: LOAD DATA WITH CQLSH
The CQL shell, or cqlsh
, is one tool to use in interacting with the database.
We’ll use it to load some data into the database using the script you just saved.
docker run --rm --network cassandra \
-v "$(pwd)/data.cql:/scripts/data.cql" \
-e CQLSH_HOST=cassandra -e CQLSH_PORT=9042 \
-e CQLVERSION=3.4.6 nuvo/docker-cqlsh
The cassandra server itself (the first docker run command you ran) takes a few seconds to start up. The above command will throw an error if the server hasn’t finished its init sequence yet, so give it a few seconds to spin up. |
STEP 5: INTERACTIVE CQLSH
Much like an SQL shell, you can also of course use cqlsh
to run CQL commands interactively.
docker run --rm -it --network \
cassandra nuvo/docker-cqlsh cqlsh cassandra \
9042 --cqlversion='3.4.5'
This should get you a prompt like so:
Connected to Test Cluster at cassandra:9042.
[cqlsh 5.0.1 | Cassandra 4.0.4 | CQL spec 3.4.5 | Native protocol v5]
Use HELP for help.
cqlsh>
STEP 7: WRITE SOME MORE DATA
INSERT INTO store.shopping_cart
(userid, item_count)
VALUES ('4567', 20);
CONGRATULATIONS!
Hey, that wasn’t so hard, was it?
To learn more, we suggest the following next steps:
-
Read through the Cassandra Basics to learn main concepts and how Cassandra works at a high level.
-
Browse through the Case Studies to learn how other users in our worldwide community are getting value out of Cassandra.