Hazelcast is a distributed computation and storage platform for consistently low-latency querying, aggregation and stateful computation against event streams and traditional data sources. It allows you to quickly build resource-efficient, real-time applications. You can deploy it at any scale from small edge devices to a large cluster of cloud instances.

A cluster of Hazelcast nodes share both the data storage and computational load which can dynamically scale up and down. When you add new nodes to the cluster, the data is automatically rebalanced across the cluster, and currently running computational tasks (known as jobs) snapshot their state and scale with processing guarantees.

For more info, check out Hazelcast repository.

hazelcast-cpp-client is the official C++ library API for using the Hazelcast in-memory database platform. It requires C++11 support.

Hazelcast C++ client requires a working Hazelcast cluster to run. This cluster handles the storage and manipulation of the user data.

A Hazelcast cluster consists of one or more cluster members. These members generally run on multiple virtual or physical machines and are connected to each other via the network. Any data put on the cluster is partitioned to multiple members transparent to the user. It is therefore very easy to scale the system by adding new members as the data grows. Hazelcast cluster also offers resilience. Should any hardware or software problem causes a crash to any member, the data on that member is recovered from backups and the cluster continues to operate without any downtime.

The quickest way to start a single member cluster for development purposes is to use our Docker images.

docker run -p 5701:5701 hazelcast/hazelcast

This command fetches the latest Hazelcast version. You can find all available tags here.

You can also use our ZIP or TAR distributions as described here.

Hazelcast C++ client package is available for Vcpkg users. The package name is hazelcast-cpp-client.

Please see getting started on how to use Vcpkg package manager with your application. In summary,

If you use Linux or Mac:

git clone https://github.com/microsoft/vcpkg
./vcpkg/bootstrap-vcpkg.sh
./vcpkg/vcpkg install "hazelcast-cpp-client[openssl]" --recurse

If you use Windows:

git clone https://github.com/microsoft/vcpkg
.\vcpkg\bootstrap-vcpkg.bat
.\vcpkg\vcpkg install "hazelcast-cpp-client[openssl]:x64-windows" --recurse

The above code snippet will install hazelcast-cpp-client with its boost and openssl dependencies.

After the installation, the library is available for usage. For example, if you are using CMake for your builds, you can use the following cmake build command with the CMAKE_TOOLCHAIN_FILE cmake option to be the vcpkg.cmake.

cmake -B [build directory] -S . -DCMAKE_TOOLCHAIN_FILE=[path to vcpkg]/scripts/buildsystems/vcpkg.cmake
cmake --build [build directory]

You can also install the hazelcast-cpp-client with conan and from source code. You can more information from Reference Manual.

There is an example project in sample_project directory. You can run the example as below:

If you use Linux or Mac:

cmake -B build -S . -DCMAKE_TOOLCHAIN_FILE=[path to vcpkg]/scripts/buildsystems/vcpkg.cmake
cmake --build build
./build/client

If you use Windows:

cmake -B build -S . -DCMAKE_TOOLCHAIN_FILE=[path to vcpkg]\scripts\buildsystems\vcpkg.cmake && ^ 
cmake --build build && ^
.\build\Debug\client

The sample code creates a client, the client automatically connects to the cluster. It creates a map named personnel_map and puts the records inside it. It then gets all the entries from the cluster and prints them.

#include <hazelcast/client/hazelcast_client.h>
int main() {
    auto hz = hazelcast::new_client().get(); // Connects to the cluster

    auto personnel = hz.get_map("personnel_map").get();
    personnel->put<std::string, std::string>("Alice", "IT").get();
    personnel->put<std::string, std::string>("Bob", "IT").get();
    personnel->put<std::string, std::string>("Clark", "IT").get();
    std::cout << "Added IT personnel. Logging all known personnel" << std::endl;
    for (const auto &entry : personnel->entry_set<std::string, std::string>().get()) {
        std::cout << entry.first << " is in " << entry.second << " department." << std::endl;
    }
    
    return 0;
}

• Distributed, partitioned and queryable in-memory key-value store implementation, called Map
• Eventually consistent cache implementation to store a subset of the Map data locally in the memory of the client, called Near Cache
• Additional data structures and simple messaging constructs such as Set, MultiMap, Queue, Topic
• Cluster-wide unique ID generator, called FlakeIdGenerator
• Distributed, CRDT based counter, called PNCounter
• Distributed concurrency primitives from CP Subsystem such as FencedLock, Semaphore, AtomicLong
• Integration with Viridian (Hazelcast Cloud)
• Support for serverless and traditional web service architectures with Unisocket and Smart operation modes
• Ability to listen client lifecycle, cluster state and distributed data structure events
• and many more.

You can find the detailed documentation at the documentation site and the API reference.

Copyright (c) 2008-2023, Hazelcast, Inc. All Rights Reserved.

Visit www.hazelcast.com for more information.