1.
Building
Java Applica)ons
with
Cassandra
"VNDGTINWPF

2.
2000
4000
6000
8000
E000
C000
A000
0000
Client Machine
Load Balancer

3.
tim name:
Tim
role:
teacher
kristen
name:
Kristen
role:
marketing
billy role:
CEO
matt name:
Matt
role:
founder
status:
active
status:
chill

4.
https://github.com/datastax/java-­‐driver

5.
DataStax
Java
Driver
• Open
source
(ASL
2.0)
• Where
CQL
happens
• Ac9vely
developed
• Now
faster
than
ThriD
• Doesn’t
make
you
want
to
die

6.
Every Use Case
has a Story

7.
Your
Story:
ň/C[DG6JTKHVKUPQVVJGEQQNGUVʼn

8.
Gradle Build
apply plugin: 'java'
repositories {
jcenter()
}
dependencies {
compile 'com.datastax.cassandra:cassandra-driver-core:2.1.2'
testCompile 'org.testng:testng:6.8.8'
testCompile 'junit:junit:4.11'
}

9.
Cluster Interface
Cluster cluster = Cluster.builder()
.addContactPoints(“192.168.50.1”)
.build();
Session session = cluster.connect(“IoT_keyspace);
session.execute(
INSERT INTO sensor
(sensor_id, reading, time)
VALUES
(24601, 2.171828, now())”);

10.
Your
Story:
ň+LWUVYCPVVQFQCSWGT[ʼn

11.
BasicQueries
ResultSet resultSet = session.execute(SELECT * FROM sensor);
ListRow rows = resultSet.all();
for(Row row : rows) {
String sensorId = row.getString(sensor_id );
double reading = row.getDouble(reading );
Date time = row.getDate(time );
}

12.
Prepared Statements
PreparedStatement insertReading =
session.prepare(
INSERT INTO sensor
(sensor_id, reading, time) VALUES (?, ?, ?)”
);
Statement statement = insertReading
.bind(24601, 2.71828, new Date())
.setConsistencyLevel(ConsistencyLevel.QUORUM);
session.execute(statement);

13.
Your
Story:
ň+YCPVNQCFDCNCPEKPIʼn

14.
2000
4000
6000
8000
E000
C000
A000
0000
Client Machine

15.
Cluster Interface
Cluster cluster = Cluster.builder()
.addContactPoints(“192.168.50.1”)
.build();

16.
Cluster Interface
Cluster cluster = Cluster.builder()
.addContactPoints(“192.168.50.1”,
“192.168.50.4”,
“192.168.50.8”)
.build();

17.
Your
Story:
ň+ņNNLWUVQRVKOKGEQQTFKPCVQT
NQCFVJGPʼn

18.
2000
4000
6000
8000
E000
C000
A000
0000
Client Machine

19.
2000
4000
6000
8000
E000
C000
A000
0000
Client Machine
1.2ms
2.9ms
15.3ms

20.
Outsmar(ng
Yourself
• Pick
one
node
• Send
all
coordina9on
traffic
to
that
node
• Hey,
maybe
make
it
a
fat
node!
• WhiteListPolicy

21.
WhiteListing
ListInetSocketAddress whiteList = new
ArrayListInetSocketAddress();
whiteList.add(...);
Cluster c = Cluster.builder().withLoadBalancingPolicy(
new WhiteListPolicy(
new RoundRobinPolicy(),
whiteList)).build();

22.
Your
Story:
ň+OKUU,2#ʼn
[QWJCXGKUUWGU

23.
Mapper Object
apply plugin: 'java'
repositories {
jcenter()
}
dependencies {
compile 'com.datastax.cassandra:cassandra-driver-core:2.1.2'
compile 'com.datastax.cassandra:cassandra-driver-mapping:2.1.2'
testCompile 'org.testng:testng:6.8.8'
testCompile 'junit:junit:4.11'
}

24.
CREATE TABLE sensor (
sensor_id int,
reading double,
time timestamp
);
Mapper Object
@UDT(keyspace = IoT_keyspace, name = sensor)
public class Sensor {
private int sensorId;
private double reading;
private Date Time;
// getters and setters elided with extreme prejudice...
}

25.
Mapper Object
MappingManager manager = new MappingManager(session);
Mapper mapper = manager.mapper(Sensor.class);
Sensor reading = mapper.get(24601);

26.
Your
Story:
ň+NKMGUNQYSWGTKGUʼn

27.
FutureResults
ResultSetFuture future =
session.executeAsync(SELECT * FROM sensor);
// Returns immediately
// Go do productive things here…
// Then finally block on the results when you must
ResultSet futureResults = future.get();
ListRow rows = resultSet.all();

28.
FutureResults
Executor executor = Executors.newCachedThreadPool();
ResultSetFuture future =
session.executeAsync(SELECT * FROM sensor);
future.addListener(new Runnable() {
public void run() {
// Do the things here…
}
}, executor);

29.
Your
Story:
ň6TCPUOKVYKPFQYUJCXGDGGPC
VJKPINQPIGTVJCPOQUVFGXGNQRGTU
JCXGDGGPCNKXGʼn

30.
Thank
You!
VNDGTINWPF