Redis

Sources: http://redis.io/

Redis is an open source (BSD licensed), in-memory data structure store, used as a database, cache and message broker. It supports data structures such as strings, hashes, lists, sets, sorted sets with range queries, bitmaps, hyperloglogs and geospatial indexes with radius queries. Redis has built-in replication, Lua scripting, LRU eviction, transactions and different levels of on-disk persistence, and provides high availability via Redis Sentinel and automatic partitioning with Redis Cluster.

Installation on X:

Download, extract and compile Redis with:

wget http://download.redis.io/redis-stable.tar.gz

tar xzf redis-stable.tar.gz

cd redis-stable

make ##Got error cc command not found. soln. need to install 'developer tools' that includes gcc cc and other required commands for make to complete.

The binaries that are now compiled are available in the src directory. Run Redis with:

src/redis-server ##src/redis-server --protected-mode no --port 43382

You can interact with Redis using the built-in client:

src/redis-cli ##src/redis-cli -p 43382

127.0.0.1:43382> get name

"Rahul"

127.0.0.1:43382> select 1

OK

127.0.0.1:43382[1]> get name

(nil)

Connecting Java app to redis

Exception in thread "main" redis.clients.jedis.JedisException: DENIED Redis is running in protected mode because protected mode is enabled, no bind address was specified, no authentication password is requested to clients. In this mode connections are only accepted from the loopback interface. If you want to connect from external computers to Redis you may adopt one of the following solutions: 1) Just disable protected mode sending the command 'CONFIG SET protected-mode no' from the loopback interface by connecting to Redis from the same host the server is running, however MAKE SURE Redis is not publicly accessible from internet if you do so. Use CONFIG REWRITE to make this change permanent. 2) Alternatively you can just disable the protected mode by editing the Redis configuration file, and setting the protected mode option to 'no', and then restarting the server. 3) If you started the server manually just for testing, restart it with the '--protected-mode no' option. 4) Setup a bind address or an authentication password. NOTE: You only need to do one of the above things in order for the server to start accepting connections from the outside.

Example app : jedis_implementaion