Redis

• Redis is an open source, BSD licensed, advanced key-value store.
• It is often referred to as a data structure server, since the keys can contain strings, hashes, lists, sets and sorted sets.
• Redis is written in C.
• Redis holds its database entirely in the memory, using the disk only for persistence.
• Redis has a relatively rich set of data types when compared to many key-value data stores.
• Redis can replicate data to any number of slaves.
• All Redis operations are atomic, which ensures that if two clients concurrently access, Redis server will receive the updated value.

Redis Commands

redis-cli This will connect to your local server and now you can run any command.
redis-cli -h host -p port -a password To run commands on Redis remote server.

Keys

• DEL key This command deletes the key, if it exists.
• DUMP key This command returns a serialized version of the value stored at the specified key.
• EXISTS key This command checks whether the key exists or not.
• EXPIRE key seconds Sets the expiry of the key after the specified time.
• EXPIREAT key timestamp Sets the expiry of the key after the specified time. Here time is in Unix timestamp format.
• PEXPIRE key milliseconds Set the expiry of key in milliseconds.
• PEXPIREAT key milliseconds-timestamp Sets the expiry of the key in Unix timestamp specified as milliseconds.
• KEYS pattern Finds all keys matching the specified pattern.
• MOVE key db Moves a key to another database.
• PERSIST key Removes the expiration from the key.
• PTTL key Gets the remaining time in keys expiry in milliseconds.
• TTL key Gets the remaining time in keys expiry.
• RANDOMKEY Returns a random key from Redis.
• RENAME key newkey Changes the key name.
• RENAMENX key newkey Renames the key, if a new key doesn't exist.
• TYPE key Returns the data type of the value stored in the key.

String

• SET key value This command sets the value at the specified key.
• GET key Gets the value of a key.
• GETRANGE key start end Gets a substring of the string stored at a key.
• GETSET key value Sets the string value of a key and returns its old value.
• GETBIT key offset Returns the bit value at the offset in the string value stored at the key.
• MGET key1 [key2..] Gets the values of all the given keys.
• SETBIT key offset value Sets or clears the bit at the offset in the string value stored at the key.
• SETEX key seconds value Sets the value with the expiry of a key.
• SETNX key value Sets the value of a key, only if the key does not exist.
• SETRANGE key offset value Overwrites the part of a string at the key starting at the specified offset.
• STRLEN key Gets the length of the value stored in a key.
• MSET key value [key value ...] Sets multiple keys to multiple values.
• MSETNX key value [key value ...] Sets multiple keys to multiple values, only if none of the keys exist.
• PSETEX key milliseconds value Sets the value and expiration in milliseconds of a key.
• INCR key Increments the integer value of a key by one.
• INCRBY key increment Increments the integer value of a key by the given amount.
• INCRBYFLOAT key increment Increments the float value of a key by the given amount.
• DECR key Decrements the integer value of a key by one.
• DECRBY key decrement Decrements the integer value of a key by the given number.
• APPEND key value Appends a value to a key.