TimothyZhang023 / swapdb

A redis compatiable storage which support data exchange between memory and disk. the main thought of swapcache is, keep hot keys in redis and cold keys in disk, to be more important, when a disk key becomes hot, load it to redis, when a memory key becomes cold, transfter it to disk. by using swapcache, we can have both a high preformance cache and high capacity KV storage.

swapdb

A redis compatiable storage which support data exchange between memory and disk, so you can save a lot of memory cost by using swapdb compared to redis. the main thought of swapdb is, keep hot keys in redis and cold keys in disk, when a key in disk becomes hot, will load it to redis, when a key in memory becomes cold, will transfter it to disk. by using swapdb, you can have both a high preformance cache and high capacity KV storage.

Documentation

中文文档

Fundamental

Features

• Heat statistics of keys(LFU)
• Configurable threshold of RAM/FLASH capacity
• Redis API compatiable(99%). supports data structures such as strings, hashes, lists, sets, sorted sets
• Cluster management(redis cluster)
• Multiple replica nodes and data replication support(RDB+Snapshot)
• Data persistency support
• High performance and high capacity redis-like storage

Compile

requirements:

CMake >= 3.1
GCC >= 4.8

Get the source code

git clone https://github.com/JRHZRD/swapdb.git --recursive

Let's build

(you can skip this step if you add '--recursive' option when 'git clone'.) for submodules update process.

git submodule update --init --recursive

cmake . && make -j8

Quick start

you can quickly start a swap-redis and swap-ssdb instance like this:

cd utils
# this will use the default "6379" port for swap-redis and "26379" port for swap-ssdb.
./deploy_redis.sh
# or you can specify a specific port like this, for example, use "6380" port
# ./deploy_redis.sh 6380

redis-cli -p 6379
127.0.0.1:6379> set a b
OK
127.0.0.1:6379> locatekey a
"redis"
127.0.0.1:6379> storetossdb a
OK
127.0.0.1:6379> locatekey a
"ssdb"
127.0.0.1:6379> get a
"b"
127.0.0.1:6379> dumpfromssdb a
OK
127.0.0.1:6379> locatekey a
"redis"

Applicable scenes

• cache

swapdb support LFU based heat statistics, hot keys are kept in redis，so you can use swapdb as cache, which has the same performance as redis when access hot keys.

• High capacity redis-like KV storage

By configuring a low threshold of RAM/FLASH capacity, most of the data will be stored in disk and only the hottest data stored in redis.