What is Redis

1. Distributed Cache
2. Distributed In memory Database

NoSQL

Installing Redis

Latest Stable Version: http://download.redis.io/redis-stable.tar.gz 

wget http://download.redis.io/redis-stable.tar.gz
tar xvzf redis-stable.tar.gz
cd redis-stable
make
make test

Unstable : https://github.com/antirez/redis/archive/unstable.tar.gz

For windows: https://github.com/MSOpenTech/redis/releases

• redis-server redis server itself
• redis-sentinel Redis Sentinel(monitoring and failover).
• redis-cli command line interface utility
• redis-benchmark Redis performances.
• redis-check-aof and redis-check-dump are useful in the rare event of corrupted data files.

Basic Components

redis-stable/src/

Starting Server

 redis-server --test-memory

./src/redis-server

Higher Level Architecture

Redis: Server

Request-Response By Event Loop

Redis Server :  modules

Redis Data Structure : String

redis>  SET mykey "Hello"
OK
redis>  GET mykey
"Hello"
redis>  
> set mykey newval nx
(nil)
> set mykey newval xx
OK
> set counter 100
OK
> incr counter
(integer) 101
> incr counter
(integer) 102
> incrby counter 50
(integer) 152

EX-- Set the specified expire time
PX-- Set the specified expire time
NX-- Only set the key if it does not 
already exist.
XX-- Only set the key if it already exist.


> exists mykey
(integer) 1
> del mykey
(integer) 1
> exists mykey
(integer) 0

+------------+------------------------+-----------+---------------\
| Len | Free | H E L L O W O R L D \n | Null term |  Free space   \
+------------+------------------------+-----------+---------------\

https://github.com/antirez/sds

struct sdshdr {
    long len;
    long free;
    char buf[];
};

Redis Data Structure : List

> rpush mylist A
(integer) 1
> rpush mylist B
(integer) 2
> lpush mylist first
(integer) 3
> lrange mylist 0 -1
1) "first"
2) "A"
3) "B"


> rpush mylist a b c
(integer) 3
> rpop mylist
"c"
> rpop mylist
"b"
> rpop mylist
"a"

> rpush mylist 1 2 3 4 5 "foo bar"
(integer) 9
> lrange mylist 0 -1
1) "first"
2) "A"
3) "B"
4) "1"
5) "2"
6) "3"
7) "4"
8) "5"
9) "foo bar"

> rpush ids 1 2 3 4 5
(integer) 5
> ltrim ids 0 2
OK
> lrange ids 0 -1
1) "1"
2) "2"
3) "3"

Redis Data Structure : Sorted  Set

> zadd hackers 1940 "Alan Kay"
(integer) 1
> zadd hackers 1957 "Sophie Wilson"
(integer 1)
> zadd hackers 1953 "Richard Stallman"
(integer) 1
> zadd hackers 1949 "Anita Borg"
(integer) 1
> zadd hackers 1965 "Yukihiro Matsumoto"
(integer) 1
> zadd hackers 1914 "Hedy Lamarr"
(integer) 1
> zadd hackers 1916 "Claude Shannon"
(integer) 1
> zadd hackers 1969 "Linus Torvalds"
(integer) 1
> zadd hackers 1912 "Alan Turing"
(integer) 1

> zrange hackers 0 -1
1) "Alan Turing"
2) "Hedy Lamarr"
3) "Claude Shannon"
4) "Alan Kay"
5) "Anita Borg"
6) "Richard Stallman"
7) "Sophie Wilson"
8) "Yukihiro Matsumoto"
9) "Linus Torvalds"

> zrevrange hackers 0 -1
1) "Linus Torvalds"
2) "Yukihiro Matsumoto"
3) "Sophie Wilson"
4) "Richard Stallman"
5) "Anita Borg"
6) "Alan Kay"
7) "Claude Shannon"
8) "Hedy Lamarr"
9) "Alan Turing"

Redis Data Structure : Sorted Set

> zrangebyscore hackers -inf 1950
1) "Alan Turing"
2) "Hedy Lamarr"
3) "Claude Shannon"
4) "Alan Kay"
5) "Anita Borg"

zremrangebyscore hackers 1940 1960
(integer) 4

> zrank hackers "Anita Borg"
(integer) 4

Skiplist

Redis Data Structure : Hashes

> hmset user:1000 username antirez birthyear 1977 verified 1
OK
> hget user:1000 username
"antirez"
> hget user:1000 birthyear
"1977"
> hgetall user:1000
1) "username"
2) "antirez"
3) "birthyear"
4) "1977"
5) "verified"
6) "1"

> hincrby user:1000 birthyear 10
(integer) 1987
> hincrby user:1000 birthyear 10
(integer) 1997

127.0.0.1:6379> COMMAND COUNT
(integer) 163

Redis With Spring Boot

Depedency

dependencies {
    compile 'org.springframework.boot:spring-boot-starter-web'
    compile 'org.springframework.boot:spring-boot-starter-actuator'
    compile 'org.springframework.boot:spring-boot-starter-redis:1.1.5.RELEASE'
    compile 'com.google.guava:guava:17.0'
    compile 'org.apache.commons:commons-lang3:3.3.2'
    compile 'commons-validator:commons-validator:1.4.0'
}

shakhawat.hossain@shakhawat:/usr/local/redis-server/redis-stable$ redis-server
31254:C 25 Aug 12:49:52.803 # Warning: no config file specified, using the default config. In order to specify a config file use redis-server /path/to/redis.conf
31254:M 25 Aug 12:49:52.803 # You requested maxclients of 10000 requiring at least 10032 max file descriptors.
31254:M 25 Aug 12:49:52.803 # Redis can't set maximum open files to 10032 because of OS error: Operation not permitted.
31254:M 25 Aug 12:49:52.803 # Current maximum open files is 4096. maxclients has been reduced to 4064 to compensate for low ulimit. If you need higher maxclients increase 'ulimit -n'.
                _._                                                  
           _.-``__ ''-._                                             
      _.-``    `.  `_.  ''-._           Redis 3.0.3 (00000000/0) 64 bit
  .-`` .-```.  ```\/    _.,_ ''-._                                   
 (    '      ,       .-`  | `,    )     Running in standalone mode
 |`-._`-...-` __...-.``-._|'` _.-'|     Port: 6379
 |    `-._   `._    /     _.-'    |     PID: 31254
  `-._    `-._  `-./  _.-'    _.-'                                   
 |`-._`-._    `-.__.-'    _.-'_.-'|                                  
 |    `-._`-._        _.-'_.-'    |           http://redis.io        
  `-._    `-._`-.__.-'_.-'    _.-'                                   
 |`-._`-._    `-.__.-'    _.-'_.-'|                                  
 |    `-._`-._        _.-'_.-'    |                                  
  `-._    `-._`-.__.-'_.-'    _.-'                                   
      `-._    `-.__.-'    _.-'                                       
          `-._        _.-'                                           
              `-.__.-'                                               

Start Server

Redis With Spring Boot

@EnableAutoConfiguration
@Controller
public class UrlShortenerController {

    private static final String DOMAIN_URL = "http://rds.com/";
    private static final String[] VALID_SCHEMES = {"http", "https"};

    @Autowired
    private StringRedisTemplate redis;

    @RequestMapping(value = "/{urlCode}", method = RequestMethod.GET)
    public void redirect(@PathVariable String urlCode,
                         HttpServletResponse resp) throws Exception {
        String url = redis.opsForValue().get(urlCode);

        if (url != null) {
            resp.sendRedirect(url);
        } else {
            resp.sendError(HttpServletResponse.SC_NOT_FOUND);
        }
    }

    @RequestMapping(method = RequestMethod.POST)
    public ResponseEntity<String> save(HttpServletRequest req) {
        String queryParams = req.getQueryString() != null ? "?" + req.getQueryString() : "";
        String url = (req.getRequestURI() + queryParams).substring(1);

        UrlValidator urlValidator = new UrlValidator(VALID_SCHEMES);

        if (urlValidator.isValid(url)) {
            String urlCode = Hashing.murmur3_32().hashString(url, StandardCharsets.UTF_8).toString();
            redis.opsForValue().set(urlCode, url);
            return new ResponseEntity<>(DOMAIN_URL + urlCode, HttpStatus.OK);
        }

        return new ResponseEntity<>(HttpStatus.BAD_REQUEST);
    }
}

Redis Most Common Usage

High Traffic News Portals

Gaming Data : Leader Board

Timeline

Follower Model

http://stackshare.io/redis

Popularity In Developer Community

db-engine ranking

Repo

Popularity In Developer Community

Thank You All