DataStax C/C++ Driver for Apache Cassandra

A modern, feature-rich, and highly tunable C/C++ client library for Apache Cassandra (1.2+) and DataStax Enterprise (3.1+) using exclusively Cassandra's native protocol and Cassandra Query Language v3.

What's New in 2.5/2.6

Support for duration
Speculative execution
Idempotent statements
SSL can be enabled without re-initializing the underlying library (e.g. OpenSSL)

More information about features included in 2.3 can be found in this blog post.

Upgrading from 2.0 or 2.1 to 2.2+

The new schema metadata API in 2.2 required some breaking API changes. Applications that used the previous schema metadata API from 2.0 and 2.1 will require some small modifications to use the new API. More information about the new schema metadata API can be found in this blog post.

Upgrading from 1.0 to 2.0+

There were a couple breaking API changes between 1.0 and 2.0 that are documented here.

Features

Asynchronous API
Simple, Prepared, and Batch statements
Asynchronous I/O, parallel execution, and request pipelining
Connection pooling
Automatic node discovery
Automatic reconnection
Configurable load balancing
Works with any cluster size
Authentication
SSL
Latency-aware routing
Performance metrics
Tuples and UDTs
Nested collections
Retry policies
Client-side timestamps
Data types
Idle connection heartbeats
Support for materialized view and secondary index metadata
Support for clustering key order, frozen<> and Cassandra version metadata
Blacklist, whitelist DC, and blacklist DC load balancing policies
Custom authenticators
Reverse DNS with SSL peer identity verification support
Randomized contact points

Compatibility

This release is compatible with Apache Cassandra 1.2, 2.0, 2.1, 2.2 and 3.0.

A complete compatibility matrix for both Apache Cassandra and DataStax Enterprise can be found here.

Installation

Binary packages are available for CentOS, Ubuntu and Windows. Packages for the driver's dependencies, libuv (1.x) and OpenSSL, are also provided under the dependencies directory for each platform e.g. CentOS 7, Ubuntu 14.04, Windows.

Note: CentOS and Ubuntu use the version of OpenSSL provided with the distribution.

The driver can also be built from source.

Feedback Requested

Help us focus our efforts! Provide your input on the C/C++ Driver Platform and Runtime Survey (we kept it short).

Examples

There are several examples provided here: examples.

A Simple Example

#include <cassandra.h>
#include <stdio.h>

int main(int argc, char* argv[]) {
  /* Setup and connect to cluster */
  CassFuture* connect_future = NULL;
  CassCluster* cluster = cass_cluster_new();
  CassSession* session = cass_session_new();
  char* hosts = "127.0.0.1";
  if (argc > 1) {
    hosts = argv[1];
  }

  /* Add contact points */
  cass_cluster_set_contact_points(cluster, hosts);

  /* Provide the cluster object as configuration to connect the session */
  connect_future = cass_session_connect(session, cluster);

  if (cass_future_error_code(connect_future) == CASS_OK) {
    CassFuture* close_future = NULL;

    /* Build statement and execute query */
    const char* query = "SELECT release_version FROM system.local";
    CassStatement* statement = cass_statement_new(query, 0);

    CassFuture* result_future = cass_session_execute(session, statement);

    if (cass_future_error_code(result_future) == CASS_OK) {
      /* Retrieve result set and get the first row */
      const CassResult* result = cass_future_get_result(result_future);
      const CassRow* row = cass_result_first_row(result);

      if (row) {
        const CassValue* value = cass_row_get_column_by_name(row, "release_version");

        const char* release_version;
        size_t release_version_length;
        cass_value_get_string(value, &release_version, &release_version_length);
        printf("release_version: '%.*s'\n", (int)release_version_length, release_version);
      }

      cass_result_free(result);
    } else {
      /* Handle error */
      const char* message;
      size_t message_length;
      cass_future_error_message(result_future, &message, &message_length);
      fprintf(stderr, "Unable to run query: '%.*s'\n", (int)message_length, message);
    }

    cass_statement_free(statement);
    cass_future_free(result_future);

    /* Close the session */
    close_future = cass_session_close(session);
    cass_future_wait(close_future);
    cass_future_free(close_future);
  } else {
    /* Handle error */
    const char* message;
    size_t message_length;
    cass_future_error_message(connect_future, &message, &message_length);
    fprintf(stderr, "Unable to connect: '%.*s'\n", (int)message_length, message);
  }

  cass_future_free(connect_future);
  cass_cluster_free(cluster);
  cass_session_free(session);

  return 0;
}

License

Licensed under the Apache License, Version 2.0 (the “License”); you may not use this file except in compliance with the License. You may obtain a copy of the License at

http://www.apache.org/licenses/LICENSE-2.0

Unless required by applicable law or agreed to in writing, software distributed under the License is distributed on an “AS IS” BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the License for the specific language governing permissions and limitations under the License.