KALI ROHAN KOKA

AZEEM HIRANI

REDIS(Remote dictionary server)

A Simple database Implementing a Dictionary where keys are associated with values.

For e.g.: It can set the key “surname_1987” to the string “Rohan”.

It is open sourced. First released in March 2009.Redis takes entire dataset in memory. Dump of

dataset is created and loaded whenever server is restarted.

Speed is the key feature. Estimated 80000+ operations per second at least

WHAT IS REDIS

Values can be associated with:Strings – Binary safe so they can hold

text, images, compressed data, etc.Lists – Lists of Strings for operations

like append, list length, range of elements, sorting of lists

Sets – Addition and deletion of elements from a set, Intersection, union, subtraction, etc.

Zsets – Zadd, Zrange, Zscore, Zcard

Redis data types

Some features like those of Memcached:

All data lives in the memory.Faster, Light weightData exists in the memorySupport Multiple databasesSupport for Integer countersAtomic operations

Similarities with memcached

Memcached is not persistent.Memcached does not save as the purpose is

to be used only as a cache.Redis has capability of being used as main DB

for the application.Memcached uses key value model like Redis

but keys can be just string.In Redis, values can be Lists, Sets, Zsets.

Differences with memcached

Strings- get, set, increment, decrement

Lists- push, pop, length, range, trim

Sets- add, remove, move, length, intersect, intersect

Some more commands useful – save, lastsave (can be used to force and verify disk persistance)

Overview of Commands

These type of commands operate on database. They do not operate on individual keys.

SELECTMOVEFLUSHALLSHUTDOWNSLAVEOFDBSIZEINFOMONITOR

Database Commands

Pick your own Level.

Redis supports Persistence

Replication – Works as a master slave

Publish/Subscribe

Advantages of using REDIS

Unreliable

Indexes take a lot of RAM.

Disadvantages