C* Summit EU 2013: Cassandra Made Simple with CQL Drivers and DevCenter

Michaël Figuiere, Software Engineer, DataStax !

Alex Popescu, Sen.Product Manager, DataStax

Cassandra made simple with CQL drivers and DevCenter

#CASSANDRAEU

#CASSANDRAEUAgenda

•Why building tools for Cassandra?

•DataStax Drivers •Core values

•Introducing DevCenter

#CASSANDRAEUMotivation

«Use the right tool for the job»

... the best tools for the job

#CASSANDRAEUWhy building tools for C*

•Too many choices

•Best practices

•distributed systems

•modern applications

•Friendly, Familiar, Integrated experience

#CASSANDRAEUOne way or another

•Learn & experiment

•Implement

•Test

•Integrate

!

•Repeat

CQL The new face of Cassandra* CQL

* Simpler Data Model using Denormalized Tables * SQL-like Query Language * Schema Definition

* CQL Native Protocol * Introduced in Cassandra 1.2 * Designed for CQL * Thrift will keep being supported by Cassandra

* Reference Implementation

* Asynchronous architecture based on Netty

* Prepared Statements Support

* Automatic Fail-over

* Node Discovery

* Cassandra Tracing Support

* Tunable Policies

!

CQL Drivers Overview

Client

Without Request

Pipelining

With Request

Pipelining

Request PipeliningCassandra

Client Cassandra

Client

Without Notifications

With Notifications

NodeNode

Node

ClientNode

Node

Node

Notifications

Client Thread

Nod

Nod

Nod

Client Thread

Client Thread Nod

Driver

Asynchronous Architecture

1

23

4

5

6Client Thread

Client Thread

Client Thread

Driver

Asynchronous Architecture

Nod

Nod

Nod

Nod

Connect and Write

Cluster cluster = new Cluster.builder() .addContactPoints("10.0.0.1", "10.0.0.2") .build();!Session session = cluster.connect("myKeyspace");!session.execute( "INSERT INTO user (user_id, name, email) VALUES (12345, 'johndoe', 'john@doe.com')");

Read from a table

ResultSet rs = session.execute("SELECT * FROM test");!List<Row> rows = rs.all(); for (Row row : rows) {! String userId = row.getString("user_id"); String name = row.getString("name"); String email = row.getString("email");}

Asynchronous Read

ResultSetFuture future = session.executeAsync("SELECT * FROM test");!for (Row row : future.get()) {! String userId = row.getString("user_id"); String name = row.getString("name"); String email = row.getString("email");}

Read with Callbacksfinal ResultSetFuture future = session.executeAsync("SELECT * FROM test");!future.addListener(new Runnable() { public run() { for (Row row : future.get()) {! String userId = row.getString("user_id"); String name = row.getString("name"); String email = row.getString("email"); } }}, executor);

public void setUserByPreparedStatement(User user) {!! BoundStatement bs = setUser.bind();!! bs.setString("username", user.getUsername());! bs.setString("firstname", user.getFirstname());! bs.setString("lastname", user.getLastname());! bs.setString("email", user.getEmail());! bs.setDate("created_date", user.getCreated_date());!! ! ! session.execute(bs); !}

Using Prepared Statements

Query query = select().all().from("videodb", "videos")! .where(eq("videoId", videoId)).limit(10);!! query.setConsistencyLevel(ConsistencyLevel.ONE);!! ResultSet rs = session.execute(query);!

Using the Query Builder

Load Balancing

Policy

Node

Node

Node

Load Balancing and Failover

Client

Retry Policy

Response

1 3

2

4

5

6

Health Monitor

Reconnection Notifications

Node

Node

NodeClient

Datacenter B

Client

Client

Datacenter A Local nodes are queried first, if non are available, the request will be sent to a remote node.

Multi Datacenter Load Balancing

Node

Node

NodeClient

Client

Client

Token Aware Load Balancing

Node

Node

Replica Node

Client

Node

NodeReplica

Replica

Nodes that own a Replica of the data being read or written by the query will be contacted first.

!!cluster = Cluster.builder()! .addContactPoints("10.0.0.1", "10.0.0.2") .withLoadBalancingPolicy(Policies.defaultLoadBalancingPolicy())! .build();!!session = cluster.connect(keyspace);!

Create your own policy!

Add a Load Balancing Policy

Client Page 1

+ Paging State 1

Nod

Nod Repli

Repli

Nod Repli

Automatic Paging

Query

Client

Page 2 + Paging State 2

Nod

Nod Repli

Repli

Nod Repli

Automatic Paging

Query + Paging State 1

Introducing DevCenter 1.0

#CASSANDRAEUDevCenter•DevCenter is a free visual query tool that can be used by both developers and admins for creating and running CQL queries and commands against Apache Cassandra and DataStax Enterprise

•DevCenter is the smarter and friendlier brother of cqlsh

#CASSANDRAEUDevCenter

Pull a Steve Jobs...

... brag about how brilliant DevCenter is

#CASSANDRAEU

*DataStax drivers:

http://github.com/datastax

*DevCenter:

http://www.datastax.com/dev/blog/datastax-devcenter-1-0-is-here

http://www.datastax.com/download/clientdrivers

!

Quick links