com.datastax.driver.core.OperationTimedOutException

Question

我使用 Cassandra 创建了以下测试 class。

private static String server_ip = "127.0.0.1";
private static String keyspace = "hr";

private static Cluster cluster = null;
private static Session session = null;

public static void main (String [] args)
{
    if(cluster!=null) return;

    cluster = Cluster.builder().addContactPoints(server_ip).withPort(9042).build();


    final Metadata metadata = cluster.getMetadata();
    String msg = String.format("Connected to cluster: %s", metadata.getClusterName());
    System.out.println(msg);

    System.out.println("List of hosts");
    for (final Host host : metadata.getAllHosts())
    {
        msg = String.format("Datacenter: %s; Host: %s; Rack: %s",
        host.getDatacenter(),
        host.getAddress(),
        host.getRack());
        System.out.println(msg);
    }
    session = cluster.connect(keyspace);
}

(Cluster.java:407) 在 samples.SampleB.main(SampleB.java:28)

谷歌搜索后，我尝试了所有建议的解决方案，但都没有成功。你能帮我解决这个问题吗？非常感谢。

Answer 1

您应该验证这些依赖关系：

<!-- Apache Cassandra Datastax's CQL driver. -->
 
<dependency>
  <groupId>com.datastax.cassandra</groupId>
  <artifactId>cassandra-driver-core</artifactId>
  <version>3.1.0</version>
</dependency>
 
<dependency>
  <groupId>com.datastax.cassandra</groupId>
  <artifactId>cassandra-driver-mapping</artifactId>
  <version>3.1.0</version>
</dependency>

HTH