Redis training for java software engineers

© All rights reserved: Moshe Kaplan© All rights reserved: Moshe Kaplan Redis for Java Software Engineers© All rights reserved: Moshe Kaplan© All rights reserved: Moshe Kaplan Redis for Java Software Engineers
Redisfor Java Software Engineers
Copyrights © Moshe Kaplan
moshe.kaplan@brightaqua.com

Redis
for Java Software Engineers
Moshe Kaplan
Scale Hacker
http://top-performance.blogspot.com
http://blogs.microsoft.co.il/vprnd

© All rights reserved: Moshe Kaplan© All rights reserved: Moshe Kaplan Redis for Java Software Engineers
About Me: It’s all About
3
Scale

NOSQL MARKET
Introduction
4

When Should I Choose NoSQL?
• Eventually Consistent
• Document Store
• Key Value
5
http://guyharrison.squarespace.com/blog/tag/nosq

Key Value Store
• insert
• get
• multiget
• remove
• truncate
6
<Key, Value>
http://wiki.apache.org/cassandra/API

Redis
• Very simple protocol (SMTP like)
• Amazing Performance (60Kqps ops on 1 CPU machine)
• Persistency to disk
• Very little security

HELLO. MY NAME IS REDIS
Introduction
8

9
#10 Most Popular DB Engine
http://db-engines.com/en/ranking

Who is Using Redis?

Who is Behind Redis

Installation: Give Yourself 5min
• sudo apt-get install -y build-essential tcl8.5
• wget http://download.redis.io/releases/redis-stable.tar.gz
• tar xzf redis-stable.tar.gz
• cd redis-stable
• make
• sudo make install
• cd utils
• sudo ./install_server.sh
• sudo service redis_6379 start
• redis-cli

Redis and Data Models

Redis Data Models
Data Types What?
Binary-safe strings Strings
Lists Strings List
Sets Unique unsorted strings
Sorted Sets Score field
Hashes O(1)
Bit Arrays/Bitmaps Bit operations on set
HyperLogLogs Estimate set cardinality

Key Design
• Keep keys short
• But not too short (readable, existing overhead)
• Use Convention:
• comment:1234:reply.to

Sets
simple storage

Basic Sets
> SET counter 100
OK
> GET counter
(integer) 100
> inc counter
(integer) 101
> incby counter 50
(integer) 151
DECR DECRBY

Multi Set
> MSET counter 100 cnt2 102 cnt3 103
OK
> MGET counter cnt2 cnt 3
(integer) 100
(integer) 102
(integer) 103

Existence
> exists counter
(integer) 1
> type counter
integer
> del counter
(integer) 1

TTL Keys
> expire counter 5
(integer) 1
> set cnt2 ex 5
OK
> ttl cnt
5
> persist cnt2
OK
Will Expire in 5 secondsWill Expire in 5 seconds
Will Expire in 5 secondsWill Expire in 5 seconds
How much time was left?How much time was left?
Remove TTLRemove TTL

Linked Lists
a basis for queues

Existence
> Adding/Removing for end/start: O(1)
> Getting other items: O(N)
LPUSH/RPUSH => Add items (Head/Tail)
LPOP/RPOP => Take items (Head/Tail)
LRANGE/RRANGE => Get items (Head/Tail)

Blocking Operations
Best for Producer/Consumer (Q)
If list is empty,calls are blocked
> BRPOP <LIST> <# of Seconds>
> BLPOP <LIST> <# of Seconds>

Capped Lists
Define how many items we want to have
> LPUSH mylist <some element>
> LTRIM mylist 0 999

Hashes
a column like data store

Existence
> hmset user:1000 username antirez birthyear 1977
OK
> hget user:1000 username
"antirez"
> hget user:1000 birthyear
"1977"
> hgetall user:1000
1) "username"
2) "antirez"
3) "birthyear"
4) "1977"

Sets
a basis for social and permissions

Set Ops
> sismember myset 3
(integer) 1
> sadd news:1000:tags 1 2 5 77
(integer) 4
> sadd tag:1:news 1000
(integer) 1
> sinter news:1000:tags news:2000:tags
,,,,

Ordered Sets (Z)
A leader board solution

Set Ops
> zadd hackers 1940 "Alan Kay"
(integer) 1
> zadd hackers 1957 "Sophie Wilson"
(integer 1)
> zrange hackers 0 -1
> zremrangebyscore hackers 1940 1960

BitMaps
Efficient Configuration and
Permissions

Set Ops
> setbit key 10 1
(integer) 1
> getbit key 10
(integer) 1
> bitcount key

Advanced Operations

Scan: You can iterate all keys!
Scan
SScan
HScan
ZScan

Lua Scripting: You have script engine
> eval "return redis.call('set','foo','bar')" 0
OK

Pub/Sub
Very nice tool, but not as good as Kafka and RabbitMQ
SUBSCRIBE first second
PUBLISH second Hello
UNSUBSCRIBE
PSUBSCRIBE news.*

Sorting
SORT mylist
SORT mylist DESC
SORT mylist ALPHA
SORT mylist BY weight_*
SORT mylist BY nosort
SORT mylist BY weight_* GET object_*
SORT mylist BY weight_* GET object_* GET #
SORT mylist BY weight_* STORE resultkey
SORT mylist BY weight_*->fieldname GET object_*->fieldname

Transactions
1. Atomic
2. Blocking all other operations
3. All or Nothing
MULTI: Start transaction
EXEC: Commit
DISCARD: “Roll back” (only before EXEC, nothing done)
WATCH: Don’t use in multi client (race conditions)

Transaction by Example
> MULTI
OK
> INCR foo
QUEUED
> INCR bar
QUEUED
> EXEC
1) (integer) 1
2) (integer) 1

Java Programming

Many Options

Securing Redis

Authentication
• By default: None
• Enable: requirepass in the config file
• Authenticate: AUTH <PASSWORD>
• Simple, Clear text
• No measures to prevent brute force

Communication Encryption
• SSL Communication encryption using stunnel/spiped
• Webdis web front layer
• Encrypt the data in the app level

Persistency

The Good, bad and Evil
• RDB
• Point in time snapshots
• Backup before critical operation
• AOF
• On every write to log (or once a seocnd)
• Log rerun at startup
• None
• In memory only solution

CACHING
47

Don’t Use Caching
48

If You Have To
49

Invalidation Can Be Nightmare
50
http://luauf.com/2009/06/08/%C2%BFque-es-memcac

Geo Load Balancing Can be Worse
51

Finally, Recovery May Not Be Better
52

KISS
53
http://marriagelifeministries.org/?p=962

Thank You !
Moshe Kaplan
moshe.kaplan@brightaqua.com
054-2291978

Redis training for java software engineers

Recommended

Recommended

More Related Content

What's hot

What's hot (15)

Viewers also liked

Viewers also liked (12)

Similar to Redis training for java software engineers

Similar to Redis training for java software engineers (20)

More from Moshe Kaplan

More from Moshe Kaplan (20)

Recently uploaded

Recently uploaded (20)

Redis training for java software engineers