SlideShare a Scribd company logo

Cassandra Day London 2015: Getting Started with Apache Cassandra and Java

DataStax Academy, profile picture
DataStax Academy

This document discusses building Java applications with Apache Cassandra. It provides an overview of building and deploying a sample auction application using Cassandra for storage. It covers designing Cassandra schemas for users, auctions, and bids, and using the DataStax Java driver mapping API to interact with Cassandra from Java code. The document also compares Spring Boot and Dropwizard frameworks for building Cassandra-backed applications.

Technology
Related topics:
NoSQL Database Insights
1 of 69
Downloaded 46 times
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
Building Java Applications Technical Evangelist for Apache Cassandra @chbatey
@chbatey Who am I? • Technical Evangelist for Apache Cassandra •Founder of Stubbed Cassandra •Help out Apache Cassandra users • DataStax •Builds enterprise ready version of Apache Cassandra • Previous: Cassandra backed apps at BSkyB
@chbatey Agenda • Everything I wish I knew before I started • Example application: Auction service - Build + Deploy - Tech stack: Spring vs Dropwizard - Configuration - Designing schemas - Example Driver code including LWTs - Continuous Integration + Testing strategies
@chbatey The old
@chbatey Scaling the old
@chbatey Uh oh :(
@chbatey Uh oh :(
@chbatey A pile of cats
@chbatey The new
@chbatey Strangulation
@chbatey Prerequisites
@chbatey Use the DataStax docs
@chbatey Say no to thrift http://exponential.io/blog/2015/01/08/cassandra-terminology/
@chbatey
@chbatey Production ready applications • Build: Gradle • Web framework: Spring boot • Monitoring: Dropwizard metrics + Graphite • Testing: Stubbed Cassandra + Cassandra Unit
@chbatey KillrAuction • Register users • Create auctions • Bid on auctions • Stream auction bids https://github.com/chbatey/killrauction https://github.com/chbatey/cassandra-customer-events
@chbatey Creating a user
@chbatey Creating an Auction
@chbatey Viewing and bidding on an Auction
@chbatey The tech stack Storage layer Front end Backend end Interaction
@chbatey Gradle for building • Or Maven/SBT • Download dependencies • Build + unit test • Acceptance tests with cucumber • Load tests with Gatling
@chbatey Build and deployment dependencies {
 compile("org.springframework.boot:spring-boot-starter-web")
 compile("org.springframework.boot:spring-boot-starter-security")
 compile("org.springframework.boot:spring-boot-starter-websocket")
 compile("org.springframework:spring-websocket:4.2.0.BUILD-SNAPSHOT")
 compile("org.springframework:spring-messaging:4.2.0.BUILD-SNAPSHOT")
 compile("com.datastax.cassandra:cassandra-driver-core:${cassandraDriverVersion}")
 compile("com.datastax.cassandra:cassandra-driver-mapping:${cassandraDriverVersion}")
 compile('io.reactivex:rxjava:1.0.8')
 
 // unit + acceptance testing
 testCompile("org.springframework.boot:spring-boot-starter-test")
 testCompile("info.cukes:cucumber-junit:${cucumberVersion}")
 testCompile("info.cukes:cucumber-spring:${cucumberVersion}")
 testCompile("org.apache.httpcomponents:httpclient:${apacheHttpVersion}")
 testCompile("org.apache.httpcomponents:fluent-hc:${apacheHttpVersion}")
 
 // for performance testing
 testCompile "org.scala-lang:scala-library:2.11.5"
 testCompile "io.gatling:gatling-app:${gatlingVersion}"ß
 }
@chbatey Languages • DataStax (open source) - C#, Java, C++, Python, Node, Ruby - Very similar programming API • Other open source - Go - Clojure - Erlang - Haskell - Many more Java/Python drivers - Perl
@chbatey DataStax Java Driver • Open source
@chbatey Dropwizard vs Spring boot
@chbatey Spring
@chbatey Configuration @Component
 @ConfigurationProperties(prefix = "cassandra")
 public class CassandraConfiguration {
 
 @NotNull
 private String[] contactPoints;
 
 @NotNull
 private String keyspace;
 
 public String[] getContactPoints() {
 return this.contactPoints;
 }
 
 public String getKeyspace() {
 return keyspace;
 }
 
 @Override
 public String toString() {
 return "CassandraConfiguration{" +
 "contactPoints=" + Arrays.toString(contactPoints) +
 ", keyspace='" + keyspace + ''' +
 '}';
 }
 }
 cassandra:
 contactPoints:
 - localhost
 keyspace: killrauction • SSL? • Socket options • Compression
@chbatey
@chbatey Cluster + Session @Component
 public class CassandraSessionFactoryBean implements FactoryBean<Session> {
 @Inject
 private CassandraConfiguration cassandraConfiguration;
 
 private Cluster cluster;
 
 @Override
 public Session getObject() throws Exception {
 cluster = Cluster.builder()
 .addContactPoints(cassandraConfiguration.getContactPoints())
 .build();
 return cluster.connect(cassandraConfiguration.getKeyspace());
 }
 @Override
 public boolean isSingleton() {
 return true;
 }
 
 @PreDestroy
 public void shutdown() {
 LOGGER.info("Shutting down cluster");
 cluster.close();
 }
 } Session per keyspace Singleton!!
@chbatey Data modelling time
@chbatey Cassandra can not join or aggregate Client Where do I go for the max?
Modelling in Cassandra CREATE TABLE customer_events( customer_id text, staff_id text, time timeuuid, store_type text, event_type text, tags map<text, text>, PRIMARY KEY ((customer_id), time)); Partition Key Clustering Column(s)
How it is stored on disk customer _id time event_type store_type tags charles 2014-11-18 16:52:04 basket_add online {'item': 'coffee'} charles 2014-11-18 16:53:00 basket_add online {'item': ‘wine'} charles 2014-11-18 16:53:09 logout online {} chbatey 2014-11-18 16:52:21 login online {} chbatey 2014-11-18 16:53:21 basket_add online {'item': 'coffee'} chbatey 2014-11-18 16:54:00 basket_add online {'item': 'cheese'} charles event_type basket_add staff_id n/a store_type online tags:item coffee event_type basket_add staff_id n/a store_type online tags:item wine event_type logout staff_id n/a store_type online chbatey event_type login staff_id n/a store_type online event_type basket_add staff_id n/a store_type online tags:item coffee event_type basket_add staff_id n/a store_type online tags:item cheese
@chbatey Requirements • Store users • Store auction metadata • Store auction bids Lowish throughput High throughput / reads of many rows Get top N bids quickly
@chbatey Designing a schema for users • Fields - Username - First name - Last name - Email addresses? • Unique user names
@chbatey Users table CREATE TABLE killrauction.users ( user_name text PRIMARY KEY, password text, salt bigint, first_name text, last_name text, emails set<text> ) ;

@chbatey User DAO private static final String CREATE_USER_STATEMENT = "INSERT INTO users (user_name, password, salt, first_name , last_name , emails ) values (?, ?, ?, ?, ?, ?)"; @PostConstruct
 public void prepareStatements() {
 createUser = session.prepare(CREATE_USER_STATEMENT);
 }
 @Inject private Session session; @Inject
 private Md5PasswordEncoder md5PasswordEncoder; @Inject
 private SecureRandom secureRandom;
 
 private PreparedStatement createUser;
 
 public void createUser(UserCreate userCreate) {
 Object salt = secureRandom.nextLong();
 String endcodedPassword = md5PasswordEncoder.encodePassword(userCreate.getPassword(), salt);
 BoundStatement boundStatement = createUser.bind(userCreate.getUserName(), endcodedPassword, salt, userCreate.getFirstName(), userCreate.getLastName(), userCreate.getEmails()); 
 session.execute(boundStatement); }
@chbatey Avoiding overwriting existing users public boolean createUser(UserCreate userCreate) {
 Object salt = secureRandom.nextLong();
 String endcodedPassword = md5PasswordEncoder.encodePassword(userCreate.getPassword(), salt);
 BoundStatement boundStatement = createUser.bind(userCreate.getUserName(), endcodedPassword, salt, userCreate.getFirstName(), userCreate.getLastName(), userCreate.getEmails()); ResultSet response = session.execute(boundStatement);
 boolean applied = response.wasApplied();
 return applied;
 } private static final String CREATE_USER_STATEMENT = "INSERT INTO users (user_name, password, salt, first_name , last_name , emails ) values (?, ?, ?, ?, ?, ?) IF NOT EXISTS";

@chbatey AuctionDao CREATE TABLE IF NOT EXISTS killrauction.auctions ( name text primary key, owner text, ends bigint); @PostConstruct
 public void prepareStatements() {
 createAuction = session.prepare("insert INTO auctions (name, owner, ends) VALUES (?, ?, ?)");
 getAuction = session.prepare("select * from auctions where name = ?");
 getAllAuctionSparse = session.prepare("select * from auctions");
 } UUID for auction or use the name? Raise a PR :)
@chbatey Auction Bids CREATE TABLE IF NOT EXISTS killrauction.auction_bids ( name TEXT, bid_time TIMEUUID, bid_user TEXT, bid_amount BIGINT, PRIMARY KEY (name, bid_amount, bid_time ) ) WITH CLUSTERING ORDER BY (bid_amount DESC ) All bids for the same auction on the same node Bids stored on disk in order of amount Descending so we can always get the top N bids
@chbatey Auction Bids
@chbatey Auction Bids @PostConstruct
 public void prepareStatements() {
 createAuction = session.prepare("insert INTO auctions (name, owner, ends) VALUES (?, ?, ?)");
 getAuction = session.prepare("select * from auctions where name = ?");
 getAllAuctionSparse = session.prepare("select * from auctions”); getAuctionBids = session.prepare("select * from auction_bids where name = ?");
 storeBid = session.prepare("INSERT INTO auction_bids (name, bid_time , bid_amount , bid_user) VALUES ( ?, ?, ?, ?);");
 } public List<Auction> getAllAuctionsSparse() {
 BoundStatement bound = getAllAuctionSparse.bind();
 return session.execute(bound).all().stream().map(row ->
 new Auction(row.getString("name"), row.getString("owner"), Instant.ofEpochMilli(row.getLong("ends"))))
 .collect(Collectors.toList());
 }
@chbatey Auction Bids @PostConstruct
 public void prepareStatements() {
 createAuction = session.prepare("insert INTO auctions (name, owner, ends) VALUES (?, ?, ?)");
 getAuction = session.prepare("select * from auctions where name = ?");
 getAllAuctionSparse = session.prepare("select * from auctions”); getAuctionBids = session.prepare("select * from auction_bids where name = ?");
 storeBid = session.prepare("INSERT INTO auction_bids (name, bid_time , bid_amount , bid_user) VALUES ( ?, ?, ?, ?);");
 } public Optional<Auction> getAuction(String auctionName) {
 BoundStatement auctionBoundStatement = getAuction.bind(auctionName);
 Row auction = session.execute(auctionBoundStatement).one();
 
 BoundStatement bidsBound = getAuctionBids.bind(auctionName);
 List<BidVo> bids = session.execute(bidsBound).all().stream().map(row ->
 new BidVo(row.getString("bid_user"),
 row.getLong("bid_amount"),
 UUIDs.unixTimestamp(row.getUUID("bid_time"))))
 .collect(Collectors.toList());
 
 return Optional.of(new Auction(auction.getString("name"),
 Instant.ofEpochMilli(auction.getLong("ends")),
 bids,
 auction.getString("owner")));
 }
@chbatey Mapping API
Modelling in Cassandra CREATE TABLE customer_events( customer_id text, staff_id text, time timeuuid, store_type text, event_type text, tags map<text, text>, PRIMARY KEY ((customer_id), time));
@chbatey Mapping API @Table(keyspace = "customers", name = "customer_events")
 public class CustomerEvent {
 @PartitionKey
 @Column(name = "customer_id")
 private String customerId;
 
 @ClusteringColumn
 private UUID time;
 
 @Column(name = "staff_id")
 private String staffId;
 
 @Column(name = "store_type")
 private String storeType;
 
 @Column(name = "event_type")
 private String eventType;
 
 private Map<String, String> tags; // ctr / getters etc }

@chbatey Mapping API @Accessor
 public interface CustomerEventDao {
 @Query("select * from customers.customer_events where customer_id = :customerId")
 Result<CustomerEvent> getCustomerEvents(String customerId);
 
 @Query("select * from customers.customer_events")
 Result<CustomerEvent> getAllCustomerEvents();
 
 } 
 @Bean
 public CustomerEventDao customerEventDao() {
 MappingManager mappingManager = new MappingManager(session);
 return mappingManager.createAccessor(CustomerEventDao.class);
 }
@chbatey Adding some type safety public enum StoreType {
 ONLINE, RETAIL, FRANCHISE, MOBILE
 } @Table(keyspace = "customers", name = "customer_events")
 public class CustomerEvent {
 @PartitionKey
 @Column(name = "customer_id")
 private String customerId;
 
 @ClusteringColumn()
 private UUID time;
 
 @Column(name = "staff_id")
 private String staffId;
 
 @Column(name = "store_type")
 @Enumerated(EnumType.STRING) // could be EnumType.ORDINAL
 private StoreType storeType;

@chbatey User defined types create TYPE store (name text, type text, postcode text) ;
 
 
 CREATE TABLE customer_events_type( customer_id text, staff_id text, time timeuuid, store frozen<store>, event_type text, tags map<text, text>, PRIMARY KEY ((customer_id), time));

@chbatey Mapping user defined types @UDT(keyspace = "customers", name = "store")
 public class Store {
 private String name;
 private StoreType type;
 private String postcode; // getters etc } @Table(keyspace = "customers", name = "customer_events_type")
 public class CustomerEventType {
 @PartitionKey
 @Column(name = "customer_id")
 private String customerId;
 
 @ClusteringColumn()
 private UUID time;
 
 @Column(name = "staff_id")
 private String staffId;
 
 @Frozen
 private Store store;
 
 @Column(name = "event_type")
 private String eventType;
 
 private Map<String, String> tags;

@chbatey Mapping user defined types @UDT(keyspace = "customers", name = "store")
 public class Store {
 private String name;
 private StoreType type;
 private String postcode; // getters etc } @Table(keyspace = "customers", name = "customer_events_type")
 public class CustomerEventType {
 @PartitionKey
 @Column(name = "customer_id")
 private String customerId;
 
 @ClusteringColumn()
 private UUID time;
 
 @Column(name = "staff_id")
 private String staffId;
 
 @Frozen
 private Store store;
 
 @Column(name = "event_type")
 private String eventType;
 
 private Map<String, String> tags;

@chbatey Dev & Test environments
@chbatey Development Env + Testing • Cassandra Unit - Embeds a single Cassandra node in the same JVM for unit testing • https://github.com/jsevellec/cassandra-unit • Cassandra Cluster Manager - Spins up small clusters locally • https://github.com/pcmanus/ccm • Stubbed Cassandra - Pretends to be a real Cassandra
@chbatey Write timeout Application C R1 R2 R3 C=QUROUM Replication factor: 3 timeout timeout Write timeout
@chbatey Unavailable Application C R1 R2 R3 C=QUROUM Replication factor: 3 Unavailable
@chbatey Example Cassandra Unit with JUnit rule @Rule
 public CassandraUnit cassandraUnitRule = new CassandraUnit(new ClassPathXmlDataSet("extendedDataSet.xml"));
 
 @Test
 public void shouldHaveLoadAnExtendDataSet() throws Exception {
 // test dao
 } <dependency> <groupId>org.cassandraunit</groupId> <artifactId>cassandra-unit</artifactId> <version>2.1.3.1</version> <scope>test</scope> </dependency>
@chbatey Cassandra cluster manager Status=Up/Down |/ State=Normal/Leaving/Joining/Moving -- Address Load Tokens Owns Host ID Rack UN 127.0.0.1 102.27 KB 256 ? 15ad7694-3e76-4b74-aea0-fa3c0fa59532 rack1 UN 127.0.0.2 102.18 KB 256 ? cca7d0bb-e884-49f9-b098-e38fbe895cbc rack1 UN 127.0.0.3 93.16 KB 256 ? 1f9737d3-c1b8-4df1-be4c-d3b1cced8e30 rack1 UN 127.0.0.4 102.1 KB 256 ? fe27b958-5d3a-4f78-9880-76cb7c9bead1 rack1 UN 127.0.0.5 93.18 KB 256 ? 66eb3f23-8889-44d6-a9e7-ecdd57ed61d0 rack1 UN 127.0.0.6 102.12 KB 256 ? e2e99a7b-c1fb-4f2a-9e4f-7a4666f8245e rack1 ccm create test -v 2.0.5 -n 6 -s
@chbatey Trace Execute CQL3 query | 2015-02-02 06:39:58.759000 | 127.0.0.1 | 0 Parsing select * from staff where name in ('chbatey', 'luket', 'jonh'); [SharedPool-Worker-1] | 2015-02-02 06:39:58.766000 | 127.0.0.1 | 7553 Preparing statement [SharedPool-Worker-1] | 2015-02-02 06:39:58.768000 | 127.0.0.1 | 9249 Executing single-partition query on staff [SharedPool-Worker-3] | 2015-02-02 06:39:58.773000 | 127.0.0.1 | 14255 Sending message to /127.0.0.3 [WRITE-/127.0.0.3] | 2015-02-02 06:39:58.773001 | 127.0.0.1 | 14756 Sending message to /127.0.0.5 [WRITE-/127.0.0.5] | 2015-02-02 06:39:58.773001 | 127.0.0.1 | 14928 Sending message to /127.0.0.3 [WRITE-/127.0.0.3] | 2015-02-02 06:39:58.774000 | 127.0.0.1 | 16035 Executing single-partition query on staff [SharedPool-Worker-1] | 2015-02-02 06:39:58.777000 | 127.0.0.5 | 1156 Enqueuing response to /127.0.0.1 [SharedPool-Worker-1] | 2015-02-02 06:39:58.777001 | 127.0.0.5 | 1681 Sending message to /127.0.0.1 [WRITE-/127.0.0.1] | 2015-02-02 06:39:58.778000 | 127.0.0.5 | 1944 Executing single-partition query on staff [SharedPool-Worker-1] | 2015-02-02 06:39:58.778000 | 127.0.0.3 | 1554 Processing response from /127.0.0.5 [SharedPool-Worker-3] | 2015-02-02 06:39:58.779000 | 127.0.0.1 | 20762 Enqueuing response to /127.0.0.1 [SharedPool-Worker-1] | 2015-02-02 06:39:58.779000 | 127.0.0.3 | 2425 Sending message to /127.0.0.5 [WRITE-/127.0.0.5] | 2015-02-02 06:39:58.779000 | 127.0.0.1 | 21198 Sending message to /127.0.0.1 [WRITE-/127.0.0.1] | 2015-02-02 06:39:58.779000 | 127.0.0.3 | 2639 Sending message to /127.0.0.6 [WRITE-/127.0.0.6] | 2015-02-02 06:39:58.779000 | 127.0.0.1 | 21208 Executing single-partition query on staff [SharedPool-Worker-1] | 2015-02-02 06:39:58.780000 | 127.0.0.5 | 304 Enqueuing response to /127.0.0.1 [SharedPool-Worker-1] | 2015-02-02 06:39:58.780001 | 127.0.0.5 | 574 Executing single-partition query on staff [SharedPool-Worker-2] | 2015-02-02 06:39:58.781000 | 127.0.0.3 | 4075 Sending message to /127.0.0.1 [WRITE-/127.0.0.1] | 2015-02-02 06:39:58.781000 | 127.0.0.5 | 708 Enqueuing response to /127.0.0.1 [SharedPool-Worker-2] | 2015-02-02 06:39:58.781001 | 127.0.0.3 | 4348 Sending message to /127.0.0.1 [WRITE-/127.0.0.1] | 2015-02-02 06:39:58.782000 | 127.0.0.3 | 5371 Executing single-partition query on staff [SharedPool-Worker-1] | 2015-02-02 06:39:58.783000 | 127.0.0.6 | 2463 Enqueuing response to /127.0.0.1 [SharedPool-Worker-1] | 2015-02-02 06:39:58.784000 | 127.0.0.6 | 2905 Sending message to /127.0.0.1 [WRITE-/127.0.0.1] | 2015-02-02 06:39:58.784001 | 127.0.0.6 | 3160 Processing response from /127.0.0.6 [SharedPool-Worker-2] | 2015-02-02 06:39:58.785000 | 127.0.0.1 | -- Request complete | 2015-02-02 06:39:58.782995 | 127.0.0.1 | 23995
@chbatey Stubbed Cassandra Application Acceptance test prime on admin port (REST) verification on admin port Admin endpoints Native protocol
@chbatey Starting / Stopping @ClassRule
 public static final ScassandraServerRule SCASSANDRA = new ScassandraServerRule(); 
 Scassandra scassandra = ScassandraFactory.createServer(); scassandra.start(); PrimingClient primingClient = scassandra.primingClient(); ActivityClient activityClient = scassandra.activityClient();
@chbatey Activity Client • Query ‣ Query text ‣ Consistency • PrepreparedStatementExecution ‣ Prepared statement text ‣ Bound variables 
 public List<Query> retrieveQueries(); public List<PreparedStatementExecution> retrievePreparedStatementExecutions() 
 public List<Connection> retrieveConnections(); public void clearAllRecordedActivity() 
 public void clearConnections();
 public void clearQueries();
 public void clearPreparedStatementExecutions();

@chbatey Priming Client • PrimingRequest ‣ Either a Query or PreparedStatement ‣ Query text or QueryPattern (regex) ‣ Consistency (default all) ‣ Result (success, read timeout, unavailable etc) ‣ Rows for successful response ‣ Column types for rows ‣ Variable types for prepared statements public void prime(PrimingRequest prime) 
 public List<PrimingRequest> retrievePreparedPrimes()
 public List<PrimingRequest> retrieveQueryPrimes()
 public void clearAllPrimes()
 public void clearQueryPrimes()
 public void clearPreparedPrimes()
 
 

@chbatey Testing errors @Test(expected = UnableToRetrievePeopleException.class)
 public void testHandlingOfReadRequestTimeout() throws Exception {
 // given
 PrimingRequest primeReadRequestTimeout = PrimingRequest.queryBuilder()
 .withQuery("select * from person")
 .withResult(Result.read_request_timeout)
 .build();
 primingClient.prime(primeReadRequestTimeout);
 
 //when
 underTest.retrievePeople();
 
 //then
 } Expecting custom exception
@chbatey Testing slow connection @Test(expected = UnableToSavePersonException.class)
 public void testThatSlowQueriesTimeout() throws Exception {
 // given
 PrimingRequest preparedStatementPrime = PrimingRequest.preparedStatementBuilder()
 .withQueryPattern("insert into person.*")
 .withVariableTypes(VARCHAR, INT, list(TIMESTAMP))
 .withFixedDelay(1000)
 .build();
 primingClient.prime(preparedStatementPrime);
 underTest.connect();
 
 underTest.storePerson(new Person("Christopher", 29, Collections.emptyList()));
 } Delays the response by 1000ms Expect a custom exception
@chbatey Continuous integration Unit tests cassandra unit stubbed cassandra Deploy application to isolated test environment with scaled down cassandra cluster Deploy to stage environment with same hardware as production for capacity testing Deploy to production Deploy to stage integrated environment + run E2E tests
@chbatey Cassandra Stress
@chbatey Monitoring - Dropwizard metrics
@chbatey Summary • Know the eco-system - Community: Get on IRC / JIRA - Tools: DataStax drivers, CCM, Cassandra-unit, DevCenter • Get used to looking at trace
@chbatey Thanks for listening • Follow me on twitter @chbatey • Cassandra + Fault tolerance posts a plenty: • http://christopher-batey.blogspot.co.uk/ • Cassandra resources: http://planetcassandra.org/

More Related Content

ODP
Android query
Michal Pavlasek
 
PPTX
Azure Table Storage: The Good, the Bad, the Ugly (15 min. lightning talk)
Sirar Salih
 
PPTX
Progressive What Apps?
Patrick Kettner
 
PDF
Kief Morris - Infrastructure is terrible
Thoughtworks
 
PDF
Raquel Guimaraes- Third party infrastructure as code
Thoughtworks
 
PPTX
SenchaCon 2016: The Once and Future Grid - Nige White
Sencha
 
PDF
MongoDB .local Toronto 2019: Using Change Streams to Keep Up with Your Data
MongoDB
 
PDF
TSAR (TimeSeries AggregatoR) Tech Talk
Anirudh Todi
 
Android query
Michal Pavlasek
 
Azure Table Storage: The Good, the Bad, the Ugly (15 min. lightning talk)
Sirar Salih
 
Progressive What Apps?
Patrick Kettner
 
Kief Morris - Infrastructure is terrible
Thoughtworks
 
Raquel Guimaraes- Third party infrastructure as code
Thoughtworks
 
SenchaCon 2016: The Once and Future Grid - Nige White
Sencha
 
MongoDB .local Toronto 2019: Using Change Streams to Keep Up with Your Data
MongoDB
 
TSAR (TimeSeries AggregatoR) Tech Talk
Anirudh Todi
 

What's hot (19)

PDF
Tsar tech talk
Anirudh Todi
 
PPTX
Client-side Rendering with AngularJS
David Lapsley
 
PPT
SenchaCon 2016: Add Magic to Your Ext JS Apps with D3 Visualizations - Vitaly...
Sencha
 
PPTX
20141001 delapsley-oc-openstack-final
David Lapsley
 
PDF
Yavorsky
Maksym Stepanchuk
 
PDF
Cassandra Day NYC - Cassandra anti patterns
Christopher Batey
 
PDF
iOS for ERREST - alternative version
WO Community
 
PDF
LA Cassandra Day 2015 - Cassandra for developers
Christopher Batey
 
PDF
Closing the Loop in Extended Reality with Kafka Streams and Machine Learning ...
confluent
 
PDF
Persisting Data on SQLite using Room
Nelson Glauber Leal
 
DOCX
Neolane API Custom SOAP request handler
David Garcia
 
PPTX
20140821 delapsley-cloudopen-public
David Lapsley
 
PPTX
Hazelcast and MongoDB at Cloud CMS
uzquiano
 
PDF
Cutting Edge Data Processing with PHP & XQuery
William Candillon
 
PDF
Micro app-framework
Michael Dawson
 
PDF
Elasticsearch und die Java-Welt
Florian Hopf
 
PDF
XQuery in the Cloud
William Candillon
 
PDF
Not your Grandma's XQuery
William Candillon
 
PDF
MongoDB .local Paris 2020: Adéo @MongoDB : MongoDB Atlas & Leroy Merlin : et ...
MongoDB
 
Tsar tech talk
Anirudh Todi
 
Client-side Rendering with AngularJS
David Lapsley
 
SenchaCon 2016: Add Magic to Your Ext JS Apps with D3 Visualizations - Vitaly...
Sencha
 
20141001 delapsley-oc-openstack-final
David Lapsley
 
Yavorsky
Maksym Stepanchuk
 
Cassandra Day NYC - Cassandra anti patterns
Christopher Batey
 
iOS for ERREST - alternative version
WO Community
 
LA Cassandra Day 2015 - Cassandra for developers
Christopher Batey
 
Closing the Loop in Extended Reality with Kafka Streams and Machine Learning ...
confluent
 
Persisting Data on SQLite using Room
Nelson Glauber Leal
 
Neolane API Custom SOAP request handler
David Garcia
 
20140821 delapsley-cloudopen-public
David Lapsley
 
Hazelcast and MongoDB at Cloud CMS
uzquiano
 
Cutting Edge Data Processing with PHP & XQuery
William Candillon
 
Micro app-framework
Michael Dawson
 
Elasticsearch und die Java-Welt
Florian Hopf
 
XQuery in the Cloud
William Candillon
 
Not your Grandma's XQuery
William Candillon
 
MongoDB .local Paris 2020: Adéo @MongoDB : MongoDB Atlas & Leroy Merlin : et ...
MongoDB
 
Ad

Similar to Cassandra Day London 2015: Getting Started with Apache Cassandra and Java (20)

PDF
Manchester Hadoop Meetup: Spark Cassandra Integration
Christopher Batey
 
PDF
Reading Cassandra Meetup Feb 2015: Apache Spark
Christopher Batey
 
PDF
3 Dundee-Spark Overview for C* developers
Christopher Batey
 
PDF
LJC Conference 2014 Cassandra for Java Developers
Christopher Batey
 
PDF
Apache Cassandra and Go
DataStax Academy
 
PDF
Munich March 2015 - Cassandra + Spark Overview
Christopher Batey
 
PDF
AWS user group Serverless in September - Chris Johnson Bidler "Go Serverless ...
AWS Chicago
 
PDF
KSQL - Stream Processing simplified!
Guido Schmutz
 
PDF
Importing Data into Neo4j quickly and easily - StackOverflow
Neo4j
 
PDF
Dublin Meetup: Cassandra anti patterns
Christopher Batey
 
PDF
Terraform: Cloud Configuration Management (WTC/IPC'16)
Martin Schütte
 
PDF
Vienna Feb 2015: Cassandra: How it works and what it's good for!
Christopher Batey
 
PDF
A Rusty introduction to Apache Arrow and how it applies to a time series dat...
Andrew Lamb
 
PDF
Jan 2015 - Cassandra101 Manchester Meetup
Christopher Batey
 
PDF
Fears, misconceptions, and accepted anti patterns of a first time cassandra a...
Kinetic Data
 
PDF
Paris Day Cassandra: Use case
Christopher Batey
 
PDF
DataStax: Making Cassandra Fail (for effective testing)
DataStax Academy
 
PDF
Graph Connect: Importing data quickly and easily
Mark Needham
 
PPTX
F&O Summit 2023 Speaker X++ Tips and Tricks.pptx
maheshsrikakulam1
 
PDF
GraphConnect Europe 2016 - Importing Data - Mark Needham, Michael Hunger
Neo4j
 
Manchester Hadoop Meetup: Spark Cassandra Integration
Christopher Batey
 
Reading Cassandra Meetup Feb 2015: Apache Spark
Christopher Batey
 
3 Dundee-Spark Overview for C* developers
Christopher Batey
 
LJC Conference 2014 Cassandra for Java Developers
Christopher Batey
 
Apache Cassandra and Go
DataStax Academy
 
Munich March 2015 - Cassandra + Spark Overview
Christopher Batey
 
AWS user group Serverless in September - Chris Johnson Bidler "Go Serverless ...
AWS Chicago
 
KSQL - Stream Processing simplified!
Guido Schmutz
 
Importing Data into Neo4j quickly and easily - StackOverflow
Neo4j
 
Dublin Meetup: Cassandra anti patterns
Christopher Batey
 
Terraform: Cloud Configuration Management (WTC/IPC'16)
Martin Schütte
 
Vienna Feb 2015: Cassandra: How it works and what it's good for!
Christopher Batey
 
A Rusty introduction to Apache Arrow and how it applies to a time series dat...
Andrew Lamb
 
Jan 2015 - Cassandra101 Manchester Meetup
Christopher Batey
 
Fears, misconceptions, and accepted anti patterns of a first time cassandra a...
Kinetic Data
 
Paris Day Cassandra: Use case
Christopher Batey
 
DataStax: Making Cassandra Fail (for effective testing)
DataStax Academy
 
Graph Connect: Importing data quickly and easily
Mark Needham
 
F&O Summit 2023 Speaker X++ Tips and Tricks.pptx
maheshsrikakulam1
 
GraphConnect Europe 2016 - Importing Data - Mark Needham, Michael Hunger
Neo4j
 
Ad

More from DataStax Academy (20)

PDF
Forrester CXNYC 2017 - Delivering great real-time cx is a true craft
DataStax Academy
 
PPTX
Introduction to DataStax Enterprise Graph Database
DataStax Academy
 
PPTX
Introduction to DataStax Enterprise Advanced Replication with Apache Cassandra
DataStax Academy
 
PPTX
Cassandra on Docker @ Walmart Labs
DataStax Academy
 
PDF
Cassandra 3.0 Data Modeling
DataStax Academy
 
PPTX
Cassandra Adoption on Cisco UCS & Open stack
DataStax Academy
 
PDF
Data Modeling for Apache Cassandra
DataStax Academy
 
PDF
Coursera Cassandra Driver
DataStax Academy
 
PDF
Production Ready Cassandra
DataStax Academy
 
PDF
Cassandra @ Netflix: Monitoring C* at Scale, Gossip and Tickler & Python
DataStax Academy
 
PPTX
Cassandra @ Sony: The good, the bad, and the ugly part 1
DataStax Academy
 
PPTX
Cassandra @ Sony: The good, the bad, and the ugly part 2
DataStax Academy
 
PDF
Standing Up Your First Cluster
DataStax Academy
 
PDF
Real Time Analytics with Dse
DataStax Academy
 
PDF
Introduction to Data Modeling with Apache Cassandra
DataStax Academy
 
PDF
Cassandra Core Concepts
DataStax Academy
 
PPTX
Enabling Search in your Cassandra Application with DataStax Enterprise
DataStax Academy
 
PPTX
Bad Habits Die Hard
DataStax Academy
 
PDF
Advanced Data Modeling with Apache Cassandra
DataStax Academy
 
PDF
Advanced Cassandra
DataStax Academy
 
Forrester CXNYC 2017 - Delivering great real-time cx is a true craft
DataStax Academy
 
Introduction to DataStax Enterprise Graph Database
DataStax Academy
 
Introduction to DataStax Enterprise Advanced Replication with Apache Cassandra
DataStax Academy
 
Cassandra on Docker @ Walmart Labs
DataStax Academy
 
Cassandra 3.0 Data Modeling
DataStax Academy
 
Cassandra Adoption on Cisco UCS & Open stack
DataStax Academy
 
Data Modeling for Apache Cassandra
DataStax Academy
 
Coursera Cassandra Driver
DataStax Academy
 
Production Ready Cassandra
DataStax Academy
 
Cassandra @ Netflix: Monitoring C* at Scale, Gossip and Tickler & Python
DataStax Academy
 
Cassandra @ Sony: The good, the bad, and the ugly part 1
DataStax Academy
 
Cassandra @ Sony: The good, the bad, and the ugly part 2
DataStax Academy
 
Standing Up Your First Cluster
DataStax Academy
 
Real Time Analytics with Dse
DataStax Academy
 
Introduction to Data Modeling with Apache Cassandra
DataStax Academy
 
Cassandra Core Concepts
DataStax Academy
 
Enabling Search in your Cassandra Application with DataStax Enterprise
DataStax Academy
 
Bad Habits Die Hard
DataStax Academy
 
Advanced Data Modeling with Apache Cassandra
DataStax Academy
 
Advanced Cassandra
DataStax Academy
 

Recently uploaded (20)

PDF
From MVP to Full-Scale Product A Startup’s Software Journey.pdf
KodekX
 
PPTX
Tartificialntelligence_presentation.pptx
ry7r52mzb4
 
PPTX
Group 1 Presentation -Planning and Decision Making .pptx
MatthewLewis227954
 
PDF
DP Operators-handbook-extract for the Mautical Institute
LeonelMejiaLarios
 
PDF
project resource management chapter-09.pdf
ssuser00e6e21
 
PPTX
A Presentation on Touch Screen Technology
memembruh336
 
PDF
Profit Center Accounting in SAP S/4HANA, S4F28 Col11
Libreria ERP
 
PDF
Enhancing emotion recognition model for a student engagement use case through...
IAESIJAI
 
PDF
Video forgery: An extensive analysis of inter-and intra-frame manipulation al...
IAESIJAI
 
PPTX
cloud_computing_Infrastucture_as_cloud_p
mainakbhattacharya20
 
PDF
Hindi spoken digit analysis for native and non-native speakers
IAESIJAI
 
PDF
Mushroom cultivation and it's methods.pdf
mailmeonrishi
 
PDF
Transform Your ITIL® 4 & ITSM Strategy with AI in 2025.pdf
PDCA Consulting
 
PDF
Getting Started with Data Integration: FME Form 101
Safe Software
 
PDF
A novel scalable deep ensemble learning framework for big data classification...
IAESIJAI
 
PPTX
Digital-Transformation-Roadmap-for-Companies.pptx
David Malick Dieng
 
PPTX
Chapter 5: Probability Theory and Statistics
RandyFin
 
PPTX
A Presentation on Artificial Intelligence
memembruh336
 
PDF
Assigned Numbers - 2025 - Bluetooth® Document
Bloombase
 
PPTX
KOM of Painting work and Equipment Insulation REV00 update 25-dec.pptx
muhammadmuneebnaeem7
 
From MVP to Full-Scale Product A Startup’s Software Journey.pdf
KodekX
 
Tartificialntelligence_presentation.pptx
ry7r52mzb4
 
Group 1 Presentation -Planning and Decision Making .pptx
MatthewLewis227954
 
DP Operators-handbook-extract for the Mautical Institute
LeonelMejiaLarios
 
project resource management chapter-09.pdf
ssuser00e6e21
 
A Presentation on Touch Screen Technology
memembruh336
 
Profit Center Accounting in SAP S/4HANA, S4F28 Col11
Libreria ERP
 
Enhancing emotion recognition model for a student engagement use case through...
IAESIJAI
 
Video forgery: An extensive analysis of inter-and intra-frame manipulation al...
IAESIJAI
 
cloud_computing_Infrastucture_as_cloud_p
mainakbhattacharya20
 
Hindi spoken digit analysis for native and non-native speakers
IAESIJAI
 
Mushroom cultivation and it's methods.pdf
mailmeonrishi
 
Transform Your ITIL® 4 & ITSM Strategy with AI in 2025.pdf
PDCA Consulting
 
Getting Started with Data Integration: FME Form 101
Safe Software
 
A novel scalable deep ensemble learning framework for big data classification...
IAESIJAI
 
Digital-Transformation-Roadmap-for-Companies.pptx
David Malick Dieng
 
Chapter 5: Probability Theory and Statistics
RandyFin
 
A Presentation on Artificial Intelligence
memembruh336
 
Assigned Numbers - 2025 - Bluetooth® Document
Bloombase
 
KOM of Painting work and Equipment Insulation REV00 update 25-dec.pptx
muhammadmuneebnaeem7
 

Cassandra Day London 2015: Getting Started with Apache Cassandra and Java

  • 1. Building Java Applications Technical Evangelist for Apache Cassandra @chbatey
  • 2. @chbatey Who am I? • Technical Evangelist for Apache Cassandra •Founder of Stubbed Cassandra •Help out Apache Cassandra users • DataStax •Builds enterprise ready version of Apache Cassandra • Previous: Cassandra backed apps at BSkyB
  • 3. @chbatey Agenda • Everything I wish I knew before I started • Example application: Auction service - Build + Deploy - Tech stack: Spring vs Dropwizard - Configuration - Designing schemas - Example Driver code including LWTs - Continuous Integration + Testing strategies
  • 13. @chbatey Say no to thrift http://exponential.io/blog/2015/01/08/cassandra-terminology/
  • 15. @chbatey Production ready applications • Build: Gradle • Web framework: Spring boot • Monitoring: Dropwizard metrics + Graphite • Testing: Stubbed Cassandra + Cassandra Unit
  • 16. @chbatey KillrAuction • Register users • Create auctions • Bid on auctions • Stream auction bids https://github.com/chbatey/killrauction https://github.com/chbatey/cassandra-customer-events
  • 20. @chbatey The tech stack Storage layer Front end Backend end Interaction
  • 21. @chbatey Gradle for building • Or Maven/SBT • Download dependencies • Build + unit test • Acceptance tests with cucumber • Load tests with Gatling
  • 22. @chbatey Build and deployment dependencies {
 compile("org.springframework.boot:spring-boot-starter-web")
 compile("org.springframework.boot:spring-boot-starter-security")
 compile("org.springframework.boot:spring-boot-starter-websocket")
 compile("org.springframework:spring-websocket:4.2.0.BUILD-SNAPSHOT")
 compile("org.springframework:spring-messaging:4.2.0.BUILD-SNAPSHOT")
 compile("com.datastax.cassandra:cassandra-driver-core:${cassandraDriverVersion}")
 compile("com.datastax.cassandra:cassandra-driver-mapping:${cassandraDriverVersion}")
 compile('io.reactivex:rxjava:1.0.8')
 
 // unit + acceptance testing
 testCompile("org.springframework.boot:spring-boot-starter-test")
 testCompile("info.cukes:cucumber-junit:${cucumberVersion}")
 testCompile("info.cukes:cucumber-spring:${cucumberVersion}")
 testCompile("org.apache.httpcomponents:httpclient:${apacheHttpVersion}")
 testCompile("org.apache.httpcomponents:fluent-hc:${apacheHttpVersion}")
 
 // for performance testing
 testCompile "org.scala-lang:scala-library:2.11.5"
 testCompile "io.gatling:gatling-app:${gatlingVersion}"ß
 }
  • 23. @chbatey Languages • DataStax (open source) - C#, Java, C++, Python, Node, Ruby - Very similar programming API • Other open source - Go - Clojure - Erlang - Haskell - Many more Java/Python drivers - Perl
  • 27. @chbatey Configuration @Component
 @ConfigurationProperties(prefix = "cassandra")
 public class CassandraConfiguration {
 
 @NotNull
 private String[] contactPoints;
 
 @NotNull
 private String keyspace;
 
 public String[] getContactPoints() {
 return this.contactPoints;
 }
 
 public String getKeyspace() {
 return keyspace;
 }
 
 @Override
 public String toString() {
 return "CassandraConfiguration{" +
 "contactPoints=" + Arrays.toString(contactPoints) +
 ", keyspace='" + keyspace + ''' +
 '}';
 }
 }
 cassandra:
 contactPoints:
 - localhost
 keyspace: killrauction • SSL? • Socket options • Compression
  • 29. @chbatey Cluster + Session @Component
 public class CassandraSessionFactoryBean implements FactoryBean<Session> {
 @Inject
 private CassandraConfiguration cassandraConfiguration;
 
 private Cluster cluster;
 
 @Override
 public Session getObject() throws Exception {
 cluster = Cluster.builder()
 .addContactPoints(cassandraConfiguration.getContactPoints())
 .build();
 return cluster.connect(cassandraConfiguration.getKeyspace());
 }
 @Override
 public boolean isSingleton() {
 return true;
 }
 
 @PreDestroy
 public void shutdown() {
 LOGGER.info("Shutting down cluster");
 cluster.close();
 }
 } Session per keyspace Singleton!!
  • 31. @chbatey Cassandra can not join or aggregate Client Where do I go for the max?
  • 32. Modelling in Cassandra CREATE TABLE customer_events( customer_id text, staff_id text, time timeuuid, store_type text, event_type text, tags map<text, text>, PRIMARY KEY ((customer_id), time)); Partition Key Clustering Column(s)
  • 33. How it is stored on disk customer _id time event_type store_type tags charles 2014-11-18 16:52:04 basket_add online {'item': 'coffee'} charles 2014-11-18 16:53:00 basket_add online {'item': ‘wine'} charles 2014-11-18 16:53:09 logout online {} chbatey 2014-11-18 16:52:21 login online {} chbatey 2014-11-18 16:53:21 basket_add online {'item': 'coffee'} chbatey 2014-11-18 16:54:00 basket_add online {'item': 'cheese'} charles event_type basket_add staff_id n/a store_type online tags:item coffee event_type basket_add staff_id n/a store_type online tags:item wine event_type logout staff_id n/a store_type online chbatey event_type login staff_id n/a store_type online event_type basket_add staff_id n/a store_type online tags:item coffee event_type basket_add staff_id n/a store_type online tags:item cheese
  • 34. @chbatey Requirements • Store users • Store auction metadata • Store auction bids Lowish throughput High throughput / reads of many rows Get top N bids quickly
  • 35. @chbatey Designing a schema for users • Fields - Username - First name - Last name - Email addresses? • Unique user names
  • 36. @chbatey Users table CREATE TABLE killrauction.users ( user_name text PRIMARY KEY, password text, salt bigint, first_name text, last_name text, emails set<text> ) ;

  • 37. @chbatey User DAO private static final String CREATE_USER_STATEMENT = "INSERT INTO users (user_name, password, salt, first_name , last_name , emails ) values (?, ?, ?, ?, ?, ?)"; @PostConstruct
 public void prepareStatements() {
 createUser = session.prepare(CREATE_USER_STATEMENT);
 }
 @Inject private Session session; @Inject
 private Md5PasswordEncoder md5PasswordEncoder; @Inject
 private SecureRandom secureRandom;
 
 private PreparedStatement createUser;
 
 public void createUser(UserCreate userCreate) {
 Object salt = secureRandom.nextLong();
 String endcodedPassword = md5PasswordEncoder.encodePassword(userCreate.getPassword(), salt);
 BoundStatement boundStatement = createUser.bind(userCreate.getUserName(), endcodedPassword, salt, userCreate.getFirstName(), userCreate.getLastName(), userCreate.getEmails()); 
 session.execute(boundStatement); }
  • 38. @chbatey Avoiding overwriting existing users public boolean createUser(UserCreate userCreate) {
 Object salt = secureRandom.nextLong();
 String endcodedPassword = md5PasswordEncoder.encodePassword(userCreate.getPassword(), salt);
 BoundStatement boundStatement = createUser.bind(userCreate.getUserName(), endcodedPassword, salt, userCreate.getFirstName(), userCreate.getLastName(), userCreate.getEmails()); ResultSet response = session.execute(boundStatement);
 boolean applied = response.wasApplied();
 return applied;
 } private static final String CREATE_USER_STATEMENT = "INSERT INTO users (user_name, password, salt, first_name , last_name , emails ) values (?, ?, ?, ?, ?, ?) IF NOT EXISTS";

  • 39. @chbatey AuctionDao CREATE TABLE IF NOT EXISTS killrauction.auctions ( name text primary key, owner text, ends bigint); @PostConstruct
 public void prepareStatements() {
 createAuction = session.prepare("insert INTO auctions (name, owner, ends) VALUES (?, ?, ?)");
 getAuction = session.prepare("select * from auctions where name = ?");
 getAllAuctionSparse = session.prepare("select * from auctions");
 } UUID for auction or use the name? Raise a PR :)
  • 40. @chbatey Auction Bids CREATE TABLE IF NOT EXISTS killrauction.auction_bids ( name TEXT, bid_time TIMEUUID, bid_user TEXT, bid_amount BIGINT, PRIMARY KEY (name, bid_amount, bid_time ) ) WITH CLUSTERING ORDER BY (bid_amount DESC ) All bids for the same auction on the same node Bids stored on disk in order of amount Descending so we can always get the top N bids
  • 42. @chbatey Auction Bids @PostConstruct
 public void prepareStatements() {
 createAuction = session.prepare("insert INTO auctions (name, owner, ends) VALUES (?, ?, ?)");
 getAuction = session.prepare("select * from auctions where name = ?");
 getAllAuctionSparse = session.prepare("select * from auctions”); getAuctionBids = session.prepare("select * from auction_bids where name = ?");
 storeBid = session.prepare("INSERT INTO auction_bids (name, bid_time , bid_amount , bid_user) VALUES ( ?, ?, ?, ?);");
 } public List<Auction> getAllAuctionsSparse() {
 BoundStatement bound = getAllAuctionSparse.bind();
 return session.execute(bound).all().stream().map(row ->
 new Auction(row.getString("name"), row.getString("owner"), Instant.ofEpochMilli(row.getLong("ends"))))
 .collect(Collectors.toList());
 }
  • 43. @chbatey Auction Bids @PostConstruct
 public void prepareStatements() {
 createAuction = session.prepare("insert INTO auctions (name, owner, ends) VALUES (?, ?, ?)");
 getAuction = session.prepare("select * from auctions where name = ?");
 getAllAuctionSparse = session.prepare("select * from auctions”); getAuctionBids = session.prepare("select * from auction_bids where name = ?");
 storeBid = session.prepare("INSERT INTO auction_bids (name, bid_time , bid_amount , bid_user) VALUES ( ?, ?, ?, ?);");
 } public Optional<Auction> getAuction(String auctionName) {
 BoundStatement auctionBoundStatement = getAuction.bind(auctionName);
 Row auction = session.execute(auctionBoundStatement).one();
 
 BoundStatement bidsBound = getAuctionBids.bind(auctionName);
 List<BidVo> bids = session.execute(bidsBound).all().stream().map(row ->
 new BidVo(row.getString("bid_user"),
 row.getLong("bid_amount"),
 UUIDs.unixTimestamp(row.getUUID("bid_time"))))
 .collect(Collectors.toList());
 
 return Optional.of(new Auction(auction.getString("name"),
 Instant.ofEpochMilli(auction.getLong("ends")),
 bids,
 auction.getString("owner")));
 }
  • 45. Modelling in Cassandra CREATE TABLE customer_events( customer_id text, staff_id text, time timeuuid, store_type text, event_type text, tags map<text, text>, PRIMARY KEY ((customer_id), time));
  • 46. @chbatey Mapping API @Table(keyspace = "customers", name = "customer_events")
 public class CustomerEvent {
 @PartitionKey
 @Column(name = "customer_id")
 private String customerId;
 
 @ClusteringColumn
 private UUID time;
 
 @Column(name = "staff_id")
 private String staffId;
 
 @Column(name = "store_type")
 private String storeType;
 
 @Column(name = "event_type")
 private String eventType;
 
 private Map<String, String> tags; // ctr / getters etc }

  • 47. @chbatey Mapping API @Accessor
 public interface CustomerEventDao {
 @Query("select * from customers.customer_events where customer_id = :customerId")
 Result<CustomerEvent> getCustomerEvents(String customerId);
 
 @Query("select * from customers.customer_events")
 Result<CustomerEvent> getAllCustomerEvents();
 
 } 
 @Bean
 public CustomerEventDao customerEventDao() {
 MappingManager mappingManager = new MappingManager(session);
 return mappingManager.createAccessor(CustomerEventDao.class);
 }
  • 48. @chbatey Adding some type safety public enum StoreType {
 ONLINE, RETAIL, FRANCHISE, MOBILE
 } @Table(keyspace = "customers", name = "customer_events")
 public class CustomerEvent {
 @PartitionKey
 @Column(name = "customer_id")
 private String customerId;
 
 @ClusteringColumn()
 private UUID time;
 
 @Column(name = "staff_id")
 private String staffId;
 
 @Column(name = "store_type")
 @Enumerated(EnumType.STRING) // could be EnumType.ORDINAL
 private StoreType storeType;

  • 49. @chbatey User defined types create TYPE store (name text, type text, postcode text) ;
 
 
 CREATE TABLE customer_events_type( customer_id text, staff_id text, time timeuuid, store frozen<store>, event_type text, tags map<text, text>, PRIMARY KEY ((customer_id), time));

  • 50. @chbatey Mapping user defined types @UDT(keyspace = "customers", name = "store")
 public class Store {
 private String name;
 private StoreType type;
 private String postcode; // getters etc } @Table(keyspace = "customers", name = "customer_events_type")
 public class CustomerEventType {
 @PartitionKey
 @Column(name = "customer_id")
 private String customerId;
 
 @ClusteringColumn()
 private UUID time;
 
 @Column(name = "staff_id")
 private String staffId;
 
 @Frozen
 private Store store;
 
 @Column(name = "event_type")
 private String eventType;
 
 private Map<String, String> tags;

  • 51. @chbatey Mapping user defined types @UDT(keyspace = "customers", name = "store")
 public class Store {
 private String name;
 private StoreType type;
 private String postcode; // getters etc } @Table(keyspace = "customers", name = "customer_events_type")
 public class CustomerEventType {
 @PartitionKey
 @Column(name = "customer_id")
 private String customerId;
 
 @ClusteringColumn()
 private UUID time;
 
 @Column(name = "staff_id")
 private String staffId;
 
 @Frozen
 private Store store;
 
 @Column(name = "event_type")
 private String eventType;
 
 private Map<String, String> tags;

  • 52. @chbatey Dev & Test environments
  • 53. @chbatey Development Env + Testing • Cassandra Unit - Embeds a single Cassandra node in the same JVM for unit testing • https://github.com/jsevellec/cassandra-unit • Cassandra Cluster Manager - Spins up small clusters locally • https://github.com/pcmanus/ccm • Stubbed Cassandra - Pretends to be a real Cassandra
  • 56. @chbatey Example Cassandra Unit with JUnit rule @Rule
 public CassandraUnit cassandraUnitRule = new CassandraUnit(new ClassPathXmlDataSet("extendedDataSet.xml"));
 
 @Test
 public void shouldHaveLoadAnExtendDataSet() throws Exception {
 // test dao
 } <dependency> <groupId>org.cassandraunit</groupId> <artifactId>cassandra-unit</artifactId> <version>2.1.3.1</version> <scope>test</scope> </dependency>
  • 57. @chbatey Cassandra cluster manager Status=Up/Down |/ State=Normal/Leaving/Joining/Moving -- Address Load Tokens Owns Host ID Rack UN 127.0.0.1 102.27 KB 256 ? 15ad7694-3e76-4b74-aea0-fa3c0fa59532 rack1 UN 127.0.0.2 102.18 KB 256 ? cca7d0bb-e884-49f9-b098-e38fbe895cbc rack1 UN 127.0.0.3 93.16 KB 256 ? 1f9737d3-c1b8-4df1-be4c-d3b1cced8e30 rack1 UN 127.0.0.4 102.1 KB 256 ? fe27b958-5d3a-4f78-9880-76cb7c9bead1 rack1 UN 127.0.0.5 93.18 KB 256 ? 66eb3f23-8889-44d6-a9e7-ecdd57ed61d0 rack1 UN 127.0.0.6 102.12 KB 256 ? e2e99a7b-c1fb-4f2a-9e4f-7a4666f8245e rack1 ccm create test -v 2.0.5 -n 6 -s
  • 58. @chbatey Trace Execute CQL3 query | 2015-02-02 06:39:58.759000 | 127.0.0.1 | 0 Parsing select * from staff where name in ('chbatey', 'luket', 'jonh'); [SharedPool-Worker-1] | 2015-02-02 06:39:58.766000 | 127.0.0.1 | 7553 Preparing statement [SharedPool-Worker-1] | 2015-02-02 06:39:58.768000 | 127.0.0.1 | 9249 Executing single-partition query on staff [SharedPool-Worker-3] | 2015-02-02 06:39:58.773000 | 127.0.0.1 | 14255 Sending message to /127.0.0.3 [WRITE-/127.0.0.3] | 2015-02-02 06:39:58.773001 | 127.0.0.1 | 14756 Sending message to /127.0.0.5 [WRITE-/127.0.0.5] | 2015-02-02 06:39:58.773001 | 127.0.0.1 | 14928 Sending message to /127.0.0.3 [WRITE-/127.0.0.3] | 2015-02-02 06:39:58.774000 | 127.0.0.1 | 16035 Executing single-partition query on staff [SharedPool-Worker-1] | 2015-02-02 06:39:58.777000 | 127.0.0.5 | 1156 Enqueuing response to /127.0.0.1 [SharedPool-Worker-1] | 2015-02-02 06:39:58.777001 | 127.0.0.5 | 1681 Sending message to /127.0.0.1 [WRITE-/127.0.0.1] | 2015-02-02 06:39:58.778000 | 127.0.0.5 | 1944 Executing single-partition query on staff [SharedPool-Worker-1] | 2015-02-02 06:39:58.778000 | 127.0.0.3 | 1554 Processing response from /127.0.0.5 [SharedPool-Worker-3] | 2015-02-02 06:39:58.779000 | 127.0.0.1 | 20762 Enqueuing response to /127.0.0.1 [SharedPool-Worker-1] | 2015-02-02 06:39:58.779000 | 127.0.0.3 | 2425 Sending message to /127.0.0.5 [WRITE-/127.0.0.5] | 2015-02-02 06:39:58.779000 | 127.0.0.1 | 21198 Sending message to /127.0.0.1 [WRITE-/127.0.0.1] | 2015-02-02 06:39:58.779000 | 127.0.0.3 | 2639 Sending message to /127.0.0.6 [WRITE-/127.0.0.6] | 2015-02-02 06:39:58.779000 | 127.0.0.1 | 21208 Executing single-partition query on staff [SharedPool-Worker-1] | 2015-02-02 06:39:58.780000 | 127.0.0.5 | 304 Enqueuing response to /127.0.0.1 [SharedPool-Worker-1] | 2015-02-02 06:39:58.780001 | 127.0.0.5 | 574 Executing single-partition query on staff [SharedPool-Worker-2] | 2015-02-02 06:39:58.781000 | 127.0.0.3 | 4075 Sending message to /127.0.0.1 [WRITE-/127.0.0.1] | 2015-02-02 06:39:58.781000 | 127.0.0.5 | 708 Enqueuing response to /127.0.0.1 [SharedPool-Worker-2] | 2015-02-02 06:39:58.781001 | 127.0.0.3 | 4348 Sending message to /127.0.0.1 [WRITE-/127.0.0.1] | 2015-02-02 06:39:58.782000 | 127.0.0.3 | 5371 Executing single-partition query on staff [SharedPool-Worker-1] | 2015-02-02 06:39:58.783000 | 127.0.0.6 | 2463 Enqueuing response to /127.0.0.1 [SharedPool-Worker-1] | 2015-02-02 06:39:58.784000 | 127.0.0.6 | 2905 Sending message to /127.0.0.1 [WRITE-/127.0.0.1] | 2015-02-02 06:39:58.784001 | 127.0.0.6 | 3160 Processing response from /127.0.0.6 [SharedPool-Worker-2] | 2015-02-02 06:39:58.785000 | 127.0.0.1 | -- Request complete | 2015-02-02 06:39:58.782995 | 127.0.0.1 | 23995
  • 59. @chbatey Stubbed Cassandra Application Acceptance test prime on admin port (REST) verification on admin port Admin endpoints Native protocol
  • 60. @chbatey Starting / Stopping @ClassRule
 public static final ScassandraServerRule SCASSANDRA = new ScassandraServerRule(); 
 Scassandra scassandra = ScassandraFactory.createServer(); scassandra.start(); PrimingClient primingClient = scassandra.primingClient(); ActivityClient activityClient = scassandra.activityClient();
  • 61. @chbatey Activity Client • Query ‣ Query text ‣ Consistency • PrepreparedStatementExecution ‣ Prepared statement text ‣ Bound variables 
 public List<Query> retrieveQueries(); public List<PreparedStatementExecution> retrievePreparedStatementExecutions() 
 public List<Connection> retrieveConnections(); public void clearAllRecordedActivity() 
 public void clearConnections();
 public void clearQueries();
 public void clearPreparedStatementExecutions();

  • 62. @chbatey Priming Client • PrimingRequest ‣ Either a Query or PreparedStatement ‣ Query text or QueryPattern (regex) ‣ Consistency (default all) ‣ Result (success, read timeout, unavailable etc) ‣ Rows for successful response ‣ Column types for rows ‣ Variable types for prepared statements public void prime(PrimingRequest prime) 
 public List<PrimingRequest> retrievePreparedPrimes()
 public List<PrimingRequest> retrieveQueryPrimes()
 public void clearAllPrimes()
 public void clearQueryPrimes()
 public void clearPreparedPrimes()
 
 

  • 63. @chbatey Testing errors @Test(expected = UnableToRetrievePeopleException.class)
 public void testHandlingOfReadRequestTimeout() throws Exception {
 // given
 PrimingRequest primeReadRequestTimeout = PrimingRequest.queryBuilder()
 .withQuery("select * from person")
 .withResult(Result.read_request_timeout)
 .build();
 primingClient.prime(primeReadRequestTimeout);
 
 //when
 underTest.retrievePeople();
 
 //then
 } Expecting custom exception
  • 64. @chbatey Testing slow connection @Test(expected = UnableToSavePersonException.class)
 public void testThatSlowQueriesTimeout() throws Exception {
 // given
 PrimingRequest preparedStatementPrime = PrimingRequest.preparedStatementBuilder()
 .withQueryPattern("insert into person.*")
 .withVariableTypes(VARCHAR, INT, list(TIMESTAMP))
 .withFixedDelay(1000)
 .build();
 primingClient.prime(preparedStatementPrime);
 underTest.connect();
 
 underTest.storePerson(new Person("Christopher", 29, Collections.emptyList()));
 } Delays the response by 1000ms Expect a custom exception
  • 65. @chbatey Continuous integration Unit tests cassandra unit stubbed cassandra Deploy application to isolated test environment with scaled down cassandra cluster Deploy to stage environment with same hardware as production for capacity testing Deploy to production Deploy to stage integrated environment + run E2E tests
  • 68. @chbatey Summary • Know the eco-system - Community: Get on IRC / JIRA - Tools: DataStax drivers, CCM, Cassandra-unit, DevCenter • Get used to looking at trace
  • 69. @chbatey Thanks for listening • Follow me on twitter @chbatey • Cassandra + Fault tolerance posts a plenty: • http://christopher-batey.blogspot.co.uk/ • Cassandra resources: http://planetcassandra.org/