Commit 36e14292 authored by Marc Vef's avatar Marc Vef
Browse files

Added: Rocksdb optimizations for ramdisk/nvram/in-memory usage

parent ac1b5a04

ifs/configure.hpp

+3 −1
Original line number Diff line number Diff line
@@ -39,8 +39,10 @@ 


// Write-ahead logging of rocksdb

//#define KV_WOL

// Optimize key value store. Eventually, different modes will be available for different workloads. TODO

// Optimize Key-Value store. Eventually, different modes will be available for different workloads. TODO

//#define KV_OPTIMIZE

// Optimize Key-Value store for tmpfs/ramdisk usage

#define KV_OPTIMIZE_RAMDISK



// RPC configuration

#define RPCPORT 4433

ifs/src/db/db_util.cpp

+23 −5
Original line number Diff line number Diff line 


#include <db/db_util.hpp>

#include <rocksdb/table.h>

#include <rocksdb/filter_policy.h>



using namespace std;
@@ -13,9 +15,7 @@ bool init_rocksdb() { 
    // create the DB if it's not already present

    options.create_if_missing = true;



#if defined(KV_OPTIMIZE)

    optimize_rocksdb(options);

#endif



    // Disable Write-Ahead Logging if configured

    rocksdb::WriteOptions write_options{};
@@ -48,7 +48,26 @@ bool init_rocksdb() { 
}



void optimize_rocksdb(rocksdb::Options& options) {



#if defined(KV_OPTIMIZE_RAMDISK)

    // as described at https://github.com/facebook/rocksdb/wiki/RocksDB-Tuning-Guide

    // use mmap read

    options.allow_mmap_reads = true;

    // disable block cache, enable blook filters and reduce the delta encoding restart interval

    rocksdb::BlockBasedTableOptions table_options{};

    table_options.filter_policy.reset(rocksdb::NewBloomFilterPolicy(10, true));

    table_options.no_block_cache = true;

    table_options.block_restart_interval = 4;

    options.table_factory.reset(NewBlockBasedTableFactory(table_options));

    // enable lightweight compression (snappy or lz4). We use lz4 for now

    options.compression = rocksdb::CompressionType::kLZ4Compression;

    // set up compression more aggressively and allocate more threads for flush and compaction

    options.level0_file_num_compaction_trigger = 1;

    options.max_background_flushes = 8;

    options.max_background_compactions = 8;

    options.max_subcompactions = 4;

    // keep all the files open

    options.max_open_files = -1;

#elif defined(KV_OPTIMIZE)

    //    rocksdb::BlockBasedTableOptions block_options{};

//    block_options.block_size = 16384 * 2;

//    options.table_factory.reset(rocksdb::NewBlockBasedTableFactory(block_options));
@@ -69,6 +88,5 @@ void optimize_rocksdb(rocksdb::Options& options) { 
    options.level0_stop_writes_trigger = 56;

//    options.arena_block_size = 1024 * 8;

//    options.compression = rocksdb::kNoCompression; // doesnt do anything





#endif

}
 
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