开源软件名称：

zb-kvs

开源软件地址：

https://gitee.com/ZNBase/zn-kvs

开源软件介绍：

0. What is ZN-KVS

ZN-KVS is a RocksDB replacement with optimized tail latency, throughput etc.

zn-kvs is designed with memory as the main storage medium and disk as the auxiliary storage medium.
ZN-KVS uses Rocksdb's WAL and SST file format to generate the logic of asynchronous disk flush.
Support Rocksdb's external interface.

Notes

ZN-KVS was only tested and production ready under Linux platform
Language bindings except C/C++ are not fully tested yet.
Existing data can be migirated from ZN-KVS directly to RocksDB, but cannot direct migrate back to ZN-KVS.
ZN-KVS was forked from RocksDB v6.2.1.

Design Principle

Homogeneous data store adjacency in memroy.
KV data and index store separated.
Index is persistently in memory.
KV data store in memory as more as possible.
Flush thread asynchronous process new kv data.

Architecture Overview

architecture

More detail of architecture desgin is here.

1. Use ZN-KVS

Compilation

Compile project to static library, which can be integrated into yourown project.

Advanced options of compilation is here.

# Add some dependenciessudo apt install libsnappy-dev zlib1g-dev libbz2-dev liblz4-dev libzstd-dev libgflags-dev gitsudo apt install build-essential  autoconf gcc  g++ ccache libncurses5-dev byacc cmake# Create build directorymkdir buildcd build# Build with defaultcmake ..make -j4

Usage of ZN-KVS

ZN-KVS inherites exported interface from Rocsdb. So you can use ZN-KVS just like Rocksdb, except that adding one line code "options.pureMemTable = true".

Example code of Usage:

int main() {  Options options = Options();  options.env = Env::Default();  options.pureMemTable = true;  rocksdb::DB* db2 = nullptr;  rocksdb::Status s = DB::Open(options, dbname_+"/db_test", &db2);  WriteOptions writeOptions = WriteOptions();  ASSERT_OK(db2->Put(writeOptions,"542", "v2"));  ASSERT_OK(db2->Put(writeOptions,"444", "v1"));  ASSERT_OK(db2->Put(writeOptions,"ps", "v3"));  ASSERT_OK(db2->Put(writeOptions,"ps", "v4"));  ASSERT_EQ("v1", OpenGet(db2,"444"));  ASSERT_EQ("v2", OpenGet(db2,"542"));  ASSERT_EQ("v4", OpenGet(db2,"ps"));  db2->Close();  delete db2;}std::string OpenGet(DB* db,const std::string& k) {  ReadOptions options;  std::string result;  Status s = db->Get(options, k, &result);  if (s.IsNotFound()) {    result = "NOT_FOUND";  } else if (!s.ok()) {    result = s.ToString();  }  return result;}