java - 无法连接到基于 Docker 的 Cassandra 容器 - "All host(s) tried for query failed"

Question

我正在尝试创建一个简单的 Java 应用程序，该应用程序可以连接到在本地计算机上运行的 Docker 容器内运行的 Cassandra。对于我的一生，我无法让它连接到容器!

我正在像这样启动我的容器。

docker run -p 9042:9042 cassandra:latest

我的 Java 代码不是很花哨..

   private Cluster cluster;
    private Session session;
    String serverIP = "localhost";

    String username = "cassandra";
    String password = "cassandra";
    String keyspace = "DefaultKeyspace";
    public static void main(String[] args) {
        CassandraTest cassandraTest = new CassandraTest();
        cassandraTest.connect("localhost");
    }

    public void connect(String node) {

        try {
            String username = "cassandra";
            String password = "cassandra";
            String keyspace = "DefaultKeyspace";

            cluster = Cluster.builder()
                    .addContactPoints(serverIP).withCredentials(username.trim(), password.trim())
                    .build();

            session = cluster.connect(keyspace);

            //  createSchema();
            Metadata metadata = cluster.getMetadata();
            System.out.println("Connected to cluster:" + metadata.getClusterName());
            for (Host host : metadata.getAllHosts()) {
                System.out.println("Datatacenter: " + host.getDatacenter()
                        + "; Host: " + host.getAddress() + "; Rack: "
                        + host.getRack());
            }
        } catch (Exception e) {

            e.printStackTrace();
        }
        getSession();
        createSchema();
    }

但不管我做什么，我总是收到这个..

com.datastax.driver.core.exceptions.NoHostAvailableException: All host(s) tried for query failed (tried: localhost/127.0.0.1:9042 (com.datastax.driver.core.exceptions.InvalidQueryException: unconfigured table schema_keyspaces))
    at com.datastax.driver.core.ControlConnection.reconnectInternal(ControlConnection.java:220)
    at com.datastax.driver.core.ControlConnection.connect(ControlConnection.java:78)
    at com.datastax.driver.core.Cluster$Manager.init(Cluster.java:1231)
    at com.datastax.driver.core.Cluster.init(Cluster.java:158)
    at com.datastax.driver.core.Cluster.connect(Cluster.java:246)
    at com.datastax.driver.core.Cluster.connect(Cluster.java:279)
    at CassandraTest.connect(CassandraTest.java:37)
    at CassandraTest.main(CassandraTest.java:27)
Exception in thread "main" java.lang.IllegalStateException: Can't use this Cluster instance because it was previously closed
    at com.datastax.driver.core.Cluster$Manager.init(Cluster.java:1213)
    at com.datastax.driver.core.Cluster.init(Cluster.java:158)
    at com.datastax.driver.core.Cluster.connect(Cluster.java:246)
    at CassandraTest.getSession(CassandraTest.java:56)
    at CassandraTest.connect(CassandraTest.java:51)
    at CassandraTest.main(CassandraTest.java:27)

我也尝试过使用 docker 主机 IP。我该如何连接？

Answer 1

您需要使用 docker-machine 的 IP 地址作为 cassandra 主机。如果 cassandra 已恢复正常，您应该能够使用 docker-machine IP 地址对其进行 cqlsh。

$ docker-machine ip
123.456.78.99
$ export CQLSH_HOST=123.456.78.99
$ cqlsh -u cassandra

Password:
Connected to Test Cluster at 123.456.78.99:9042.
[cqlsh 5.0.1 | Cassandra 3.11.6 | CQL spec 3.4.4 | Native protocol v4]
Use HELP for help.
cassandra@cqlsh>

因此，在您的代码中，不要使用 localhost，而是尝试使用 docker-machine ip