cassandra summit keynote 2014

©2014 DataStax Confidential. Do not distribute without consent.

CTO, DataStax

Jonathan EllisProject Chair, Apache Cassandra

State of Cassandra 2014

2.1http://cassandra.apache.org/download/

Cluster cluster = Cluster.builder() .addContactPoint("127.0.0.1") .withRetryPolicy( DefaultRetryPolicy.INSTANCE) .withLoadBalancingPolicy( new TokenAwarePolicy( new DCAwareRoundRobinPolicy())) .build();Session session = cluster.connect("demo");

cluster = Cluster(  contact_points=['127.0.0.1'],  load_balancing_policy=TokenAwarePolicy( DCAwareRoundRobinPolicy( local_dc='datacenter1')),  default_retry_policy = RetryPolicy())session = cluster.connect('demo’)

Cluster cluster = Cluster.Builder() .AddContactPoints("127.0.0.1") .WithRetryPolicy(DowngradingConsistencyRetryPolicy.INSTANCE) .WithLoadBalancingPolicy( new TokenAwarePolicy( new RoundRobinPolicy())  .Build();ISession session = cluster.Connect("demo");

Cassandra’s peer to peer architecture, linear scalability and multi data center active-active deployment enable mission critical eBay features for hundreds of millions users every day.

Feng Qu, principal DBA at eBay Inc

Client Coordinator

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“One of the great things about NoSQL is the ability to iterate on one's data model as one's business requires it.”

“Everything in one place is convenient until it fails. If you want to scale and be highly available, use Cassandra.”

Matt AsayMongoDB

Adrian CockcroftBattery Ventures

2.1: Performance

Read performance, 2.0 vs 2.1

Reads, post-compaction (2.0)

Reads, post-compaction (2.1)

Write performance, 2.0 vs 2.1

Competitive performance

Competitive performance

https://github.com/jbellis/YCSB

2.1: Data modeling

Lightweight transactions

Lightweight transactionsINSERT INTO users (username, name, email, password, created_date)VALUES ('pmcfadin', 'Patrick McFadin', ['patrick@datastax.com'], 'ba27e03fd9...', '2011-06-20 13:50:00')IF NOT EXISTS;

Lightweight transactionsINSERT INTO users (username, name, email, password, created_date)VALUES ('pmcfadin', 'Patrick McFadin', ['patrick@datastax.com'], 'ba27e03fd9...', '2011-06-20 13:50:00')IF NOT EXISTS;

INSERT INTO users (username, name, email, password, created_date)VALUES ('pmcfadin', 'Patrick McFadin', ['patrick@datastax.com'], 'ea24e13ad9...', '2011-06-20 13:50:01')IF NOT EXISTS;

Lightweight transactionsINSERT INTO users (username, name, email, password, created_date)VALUES ('pmcfadin', 'Patrick McFadin', ['patrick@datastax.com'], 'ba27e03fd9...', '2011-06-20 13:50:00')IF NOT EXISTS;

[applied]----------- True

INSERT INTO users (username, name, email, password, created_date)VALUES ('pmcfadin', 'Patrick McFadin', ['patrick@datastax.com'], 'ea24e13ad9...', '2011-06-20 13:50:01')IF NOT EXISTS;

Lightweight transactions

[applied] | username | created_date | name -----------+----------+----------------+---------------- False | pmcfadin | 2011-06-20 ... | Patrick McFadin

INSERT INTO users (username, name, email, password, created_date)VALUES ('pmcfadin', 'Patrick McFadin', ['patrick@datastax.com'], 'ba27e03fd9...', '2011-06-20 13:50:00')IF NOT EXISTS;

[applied]----------- True

INSERT INTO users (username, name, email, password, created_date)VALUES ('pmcfadin', 'Patrick McFadin', ['patrick@datastax.com'], 'ea24e13ad9...', '2011-06-20 13:50:01')IF NOT EXISTS;

Static columns (2.0.6)CREATE TABLE bills ( user text, balance int static, expense_id int, amount int, description text, paid boolean, PRIMARY KEY (user, expense_id));

Static columns + LWTCREATE TABLE bills ( user text, balance int static, expense_id int, amount int, description text, paid boolean, PRIMARY KEY (user, expense_id));

BEGIN BATCH UPDATE bills SET balance = -116 WHERE user='user1' IF balance = 84; INSERT INTO bills (user, expense_id, amount, description, paid) VALUES ('user1', 2, 200, 'hotel room', false);APPLY BATCH;

Atomic log appends with LWTCREATE TABLE log ( log_name text, seq int static, logged_at timeuuid, entry text, primary key (log_name, logged_at));

INSERT INTO log (log_name, seq) VALUES ('foo', 0);

Atomic log appends with LWTBEGIN BATCH

UPDATE log SET seq = 1WHERE log_name = 'foo'IF seq = 0;

INSERT INTO log (log_name, logged_at, entry)VALUES ('foo', now(), 'test');

APPLY BATCH;

User defined typesCREATE TYPE address ( street text, city text, zip_code int, phones set<text>)

CREATE TABLE users ( id uuid PRIMARY KEY, name text, addresses map<text, frozen<address>>)

SELECT id, name, addresses.city, addresses.phones FROM users;

id | name | addresses.city | addresses.phones--------------------+----------------+-------------------------- 63bf691f | jbellis | Austin | {'512-4567', '512-9999'}

Collection indexingCREATE TABLE songs ( id uuid PRIMARY KEY, artist text, album text, title text, data blob, tags set<text>);

CREATE INDEX song_tags_idx ON songs(tags);

SELECT * FROM songs WHERE tags CONTAINS 'blues';

id | album | artist | tags | title----------+---------------+-------------------+-----------------------+------------------ 5027b27e | Country Blues | Lightnin' Hopkins | {'acoustic', 'blues'} | Worrying My Mind

2.1: Operations

Counters, 2.0

Counters, 2.0

MemtableMemtableMemtable

A0 1 1

CommitlogCommitlogCommitlog

A0 1 1

1. Node A, increment by 1

Value: 1

Counters, 2.0

CommitlogCommitlogCommitlog

A0 1 1

A0 1 1

MemtableMemtableMemtable

A0 2 2

2. Node A, increment by 1

Value: 2

MemtableMemtableMemtable

A0 1 1

CommitlogCommitlogCommitlog

A0 1 1

1. Node A, increment by 1

Value: 1

Counters, 2.0

CommitlogCommitlogCommitlog

A0 1 1

A0 1 1

MemtableMemtableMemtable

A0 2 2

2. Node A, increment by 1

Value: 2

MemtableMemtableMemtable

A0 1 1

CommitlogCommitlogCommitlog

A0 1 1

1. Node A, increment by 1

Value: 1

MemtableMemtableMemtable

A0 3 0

3. Node A, decrement by 2

Value: 0

Commit LogCommit LogCommit Log

A0 1 1

A0 1 1

A0 1 -2

Counters, 2.1

Counters, 2.1

MemtableMemtableMemtable

A0 1 1

CommitlogCommitlogCommitlog

A0 1 1

1. Node A, increment by 1

Value: 1

Counters, 2.1

CommitlogCommitlogCommitlog

A0 1 1

A0 2 2

MemtableMemtableMemtable

A0 2 2

2. Node A, increment by 1

Value: 2

MemtableMemtableMemtable

A0 1 1

CommitlogCommitlogCommitlog

A0 1 1

1. Node A, increment by 1

Value: 1

Counters, 2.1

CommitlogCommitlogCommitlog

A0 1 1

A0 2 2

MemtableMemtableMemtable

A0 2 2

2. Node A, increment by 1

Value: 2

MemtableMemtableMemtable

A0 1 1

CommitlogCommitlogCommitlog

A0 1 1

1. Node A, increment by 1

Value: 1

MemtableMemtableMemtable

A0 3 0

3. Node A, decrement by 2

Value: 0

Commit LogCommit LogCommit Log

A0 1 1

A0 2 2

A0 3 0

(low contention)

(high contention)

Regular repair

Regular repair

Regular repair

Incremental repair

Implications for LCS (and STCS)bin/nodetool upgradesstables

tools/bin/sstablerepairedset --is-repaired

bin/nodetool repair

bin/nodetool repair -inc

The new row cacheCREATE TABLE notifications ( target_user text, notification_id timeuuid, source_id uuid, source_type text, activity text, PRIMARY KEY (target_user, notification_id))WITH CLUSTERING ORDER BY (notification_id DESC) AND caching = 'rows_only' AND rows_per_partition_to_cache = '3';

The new row cachetarget_user notification_id source_id source_type activity

nick e1bd2bcb- d972b679- photo tom liked

nick 321998c- d972b679- photo jake commented

nick ea1c5d35- 88a049d5- user mike created account

nick 5321998c- 64613f27- photo tom commented

nick 07581439- 076eab7e- user tyler created account

mike 1c34467a- f04e309f- user tom created account

target_user notification_id source_id source_type activity

nick e1bd2bcb- d972b679- photo tom liked

nick 321998c- d972b679- photo jake commented

nick ea1c5d35- 88a049d5- user mike created account

nick 5321998c- 64613f27- photo tom commented

nick 07581439- 076eab7e- user tyler created account

mike 1c34467a- f04e309f- user tom created account

The new row cache

The new row cachetarget_user notification_id source_id source_type activity

nick e1bd2bcb- d972b679- photo tom liked

nick 321998c- d972b679- photo jake commented

nick ea1c5d35- 88a049d5- user mike created account

nick 5321998c- 64613f27- photo tom commented

nick 07581439- 076eab7e- user tyler created account

mike 1c34467a- f04e309f- user tom created account

2.1: Testing & QA