LogoLogo
Back to Speedb.io⭐ GitHubDiscord
  • 👋About
    • Speedb Use Cases
    • Speedb Communication Channels
    • Release Cadence
    • Releases
    • Roadmap
  • 💻Getting started
    • Speedb Quick Start Example
    • Dependencies
    • How to Compile Speedb
    • Drop-in Replacement
    • Use prebuilt binaries
    • How to contribute
      • Contribute code
      • Feature request process
      • Submit a pull request
      • Add or update documentation
      • Report bugs and other issues
      • Help with new and ongoing feature development
    • Kafka Streams: How to use Speedb instead of RocksDB?
  • ✨Speedb Features
    • Memory Tracking
    • Speedb Tuning Function
    • Table Pinning Policy
    • Snapshot Optimization
    • On Thread Start Callback
    • Write Flow
    • Global Delayed write
    • Live Configuration Changes
    • Report Index Size per Column Family
    • Proactive Flushing
    • Sorted Hash Memtable
    • Paired Bloom Filter
  • ➕Enhancements
    • Range Delete Improvement
    • Dynamic Delayed Writes
    • Reduce switch memtable latency
  • 🛠️Tools
    • Log Parser
    • DB_bench: Groups
    • Beezcli Tool
  • 🔦RocksDB Basics
  • 📈Performance testing
Powered by GitBook
On this page
  • Motivation:
  • Solution:
  • How to use it?

Was this helpful?

Edit on GitHub
  1. Speedb Features

On Thread Start Callback

PreviousSnapshot OptimizationNextWrite Flow

Last updated 1 year ago

Was this helpful?

Motivation:

This is a community driven feature following issue Github .

This feature provides the ability to limit the Speedb threads to run on specific cores in order to gain performance or better control CPU usage.

Solution:

Speedb introduces a new capability that allows Speedb users to configure a callback function that will run for each Speedb thread that is being spawned.

Using this callback a user could configure the thread affinity the way the user wants.

How to use it?

An example is also available under: examples/on_thread_start_callback_example.cc

//  This example will pin all Speedb threads to the first core


#include <functional>
#include <iostream>
#include <memory>

#include "rocksdb/db.h"
#include "rocksdb/options.h"

using namespace ROCKSDB_NAMESPACE;

#if defined(OS_WIN)
std::string kDBPath = "C:\\Windows\\TEMP\\speedb_thr_affinity";
#else
std::string kDBPath = "/tmp/speedb_thr_affinity";
#endif

int main() {
  // Open the storage
  DB* db = nullptr;
  Options options;
  // create the DB if it's not already present
  options.create_if_missing = true;
  auto f = [](std::thread::native_handle_type thr) {
// callback to pin all Speedb threads to the first core.
#if defined(OS_WIN)
#include "winbase.h"
    SetThreadAffinityMask(thr, 0);
#else
#include "pthread.h"
    std::cout << "thread spawned, thread_id: " << thr << std::endl;
    cpu_set_t cpuset;
    CPU_ZERO(&cpuset);
    CPU_SET(0, &cpuset);
    pthread_setaffinity_np(thr, sizeof(cpu_set_t), &cpuset);
#endif
  };
  options.on_thread_start_callback =
      std::make_shared<std::function<void(std::thread::native_handle_type)>>(f);
  Status s = DB::Open(options, kDBPath, &db);
  assert(s.ok());

  // append new entry
  std::string key = "key_1";
  std::string put_value = "Speedb is awesome!";
  s = db->Put(WriteOptions(), key, put_value);
  assert(s.ok());

  // retrieve entry
  std::string get_value;
  s = db->Get(ReadOptions(), key, &get_value);
  assert(s.ok());
  assert(get_value == put_value);
  std::cout << get_value << std::endl;

  // close DB
  s = db->Close();
  assert(s.ok());
  return 0;
}

✨
#476