Redis Snapshotting Basics

Introduction to Snapshotting in Redis

Welcome to the next lesson in our Redis course! So far, you've explored working with Redis Streams, managing key expirations, and using Pub/Sub messaging. Now, it's time to delve into another essential feature: snapshotting in Redis. Snapshotting is a powerful technique for persisting data in Redis, ensuring durability and recoverability in case of failures.

What You'll Learn

In this lesson, you will learn how to perform manual snapshotting in Redis using Boost.Redis. By the end, you'll know how to:

  1. Use the SAVE command to create a synchronous snapshot.
  2. Use the BGSAVE command to trigger an asynchronous snapshot in the background.
  3. Handle snapshot responses and verify successful execution.

Here's a complete C++ example using Boost.Redis:

C++
#include <boost/redis.hpp>
#include <boost/redis/src.hpp>
#include <boost/asio.hpp>
#include <iostream>

namespace net = boost::asio;
using boost::redis::connection;
using boost::redis::config;
using boost::redis::request;
using boost::redis::logger;

int main()
{
    net::io_context ioc;
    auto conn = std::make_shared<connection>(ioc);

    config cfg;
    cfg.addr.host = "127.0.0.1";
    cfg.addr.port = "6379";

    conn->async_run(cfg, logger{logger::level::disabled},
                    net::consign(net::detached, conn));

    request req;
    req.push("SAVE");
    req.push("BGSAVE");

    using snapshot_response = boost::redis::response<std::string, std::string>;
    auto snapshot_resp = std::make_shared<snapshot_response>();

    conn->async_exec(req, *snapshot_resp,
        [conn, snapshot_resp](boost::system::error_code ec, std::size_t)
        {
            if (ec) {
                std::cerr << "Error executing SAVE/BGSAVE: "
                          << ec.message() << "\n";
                conn->cancel();
                return;
            }

            auto const& save_res   = std::get<0>(*snapshot_resp);
            auto const& bgsave_res = std::get<1>(*snapshot_resp);

            if (!save_res) {
                std::cerr << "SAVE failed.\n";
            } else {
                std::cout << "SAVE result: " << save_res.value() << "\n";
            }

            if (!bgsave_res) {
                std::cerr << "BGSAVE failed.\n";
            } else {
                std::cout << "BGSAVE result: " << bgsave_res.value() << "\n";
            }

            std::cout << "Manual snapshot triggered.\n";
            conn->cancel();
        });

    ioc.run();
    return 0;
}
Sign up

Join the 1M+ learners on CodeSignal

Be a part of our community of 1M+ users who develop and demonstrate their skills on CodeSignal