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 2.2

Support for new Cassandra 2.2 datatypes: tinyint, smallint, date and time
Support for custom payloads
Support for server-side warnings
UDF/UDA metadata
Whitelist load balancing policy
Default consistency has been changed from ONE to LOCAL_QUORUM

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
Compatibility with binary protocol version 1 and 2
Authentication
SSL
Latency-aware routing
Performance metrics
Tuples and UDTs
Nested collections
Retry policies
Client-side timestamps
Data types
Idle connection heartbeats

Examples

There are several examples provided here: examples.

A Simple Example

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

int main() {
  /* Setup and connect to cluster */
  CassFuture* connect_future = NULL;
  CassCluster* cluster = cass_cluster_new();
  CassSession* session = cass_session_new();

  /* Add contact points */
  cass_cluster_set_contact_points(cluster, "127.0.0.1,127.0.0.2,127.0.0.3");

  /* 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 */
    CassStatement* statement
      = cass_statement_new("SELECT keyspace_name "
                           "FROM system.schema_keyspaces", 0);

    CassFuture* result_future = cass_session_execute(session, statement);

    if(cass_future_error_code(result_future) == CASS_OK) {
      /* Retrieve result set and iterate over the rows */
      const CassResult* result = cass_future_get_result(result_future);
      CassIterator* rows = cass_iterator_from_result(result);

      while(cass_iterator_next(rows)) {
        const CassRow* row = cass_iterator_get_row(rows);
        const CassValue* value = cass_row_get_column_by_name(row, "keyspace_name");

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

      cass_result_free(result);
      cass_iterator_free(rows);
    } 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.