Use JDBC

You can add the following configurations to the pom.xml file to connect to the Presto JDBC driver:

<dependency>
    <groupId>com.facebook.presto</groupId>
    <artifactId>presto-jdbc</artifactId>
    <version>0.187</version>
</dependency>

The following connection string format is supported:

jdbc:presto://<COORDINATOR>:<PORT>/[CATALOG]/[SCHEMA]

Examples:

jdbc:presto://emr-header-1:9090               # Connect to a database by using a specific catalog and schema.
jdbc:presto://emr-header-1:9090/hive          # Connect to a database by using the hive catalog and a specific schema.
jdbc:presto://emr-header-1:9090/hive/default  # Connect to a database by using the hive catalog and the default schema.

The Presto JDBC driver supports various parameters that can be configured as URL parameters or as properties and passed to DriverManager.

• Example of passing parameters to DriverManager as properties:

  String url = "jdbc:presto://emr-header-1:9090/hive/default";
  Properties properties = new Properties();
  properties.setProperty("user", "hadoop");
  Connection connection = DriverManager.getConnection(url, properties);
  ......

• Example of passing parameters to DriverManager as URL parameters:

  String url = "jdbc:presto://emr-header-1:9090/hive/default? user=hadoop";
  Connection connection = DriverManager.getConnection(url);
  ......

The following table describes the connection parameters.

Parameter	Format	Description
user	STRING	The username.
password	STRING	The password.
socksProxy	\:\	The address and port of the SOCKS proxy server. Example: localhost:1080.
httpProxy	\:\	The address and port of the HTTP proxy server. Example: localhost:8888.
SSL	true\	Specifies whether to use HTTPS for connections. Default value: false.
SSLTrustStorePath	STRING	The path used to store the Java truststore file.
SSLTrustStorePassword	STRING	The password of the Java truststore file.
KerberosRemoteServiceName	STRING	The name of the remote Kerberos service.
KerberosPrincipal	STRING	The Kerberos principal name.
KerberosUseCanonicalHostname	true\	Specifies whether to use a normalized hostname. Default value: false.
KerberosConfigPath	STRING	The path used to store the Kerberos configuration file.
KerberosKeytabPath	STRING	The path used to store the Kerberos keytab file.
KerberosCredentialCachePath	STRING	The path used to cache the Kerberos credential.

In this example, the Presto JDBC driver is used for Java.

.....
// Load the class of the Presto JDBC driver.
try {
    Class.forName("com.facebook.presto.jdbc.PrestoDriver");
} catch(ClassNotFoundException e) {
    LOG.ERROR("Failed to load presto jdbc driver.", e);
    System.exit(-1);
}
Connection connection = null;
Statement statement = null;
try {
    String url = "jdbc:presto://emr-header-1:9090/hive/default";
    Properties properties = new Properties();
    properties.setProperty("user", "hadoop");
    // Create a connection object.
    connection = DriverManager.getConnection(url, properties);
    // Create a statement object.
    statement = connection.createStatement();
    // Execute a query statement.
    ResultSet rs = statement.executeQuery("select * from t1");
    // Return results.
    int columnNum = rs.getMetaData().getColumnCount();
    int rowIndex = 0;
    while (rs.next()) {
        rowIndex++;
        for(int i = 1; i <= columnNum; i++) {
            System.out.println("Row " + rowIndex + ", Column " + i + ": " + rs.getInt(i));
        }
    }
} catch(SQLException e) {
    LOG.ERROR("Exception thrown.", e);
} finally {
  // Destroy the statement object.
  if (statement ! = null) {
      try {
        statement.close();
    } catch(Throwable t) {
        // No-ops
    }
  }
  // Close the connection.
  if (connection ! = null) {
      try {
        connection.close();
    } catch(Throwable t) {
        // No-ops
    }
  }
}

To configure a proxy for a non-security cluster, perform the following steps:

1. Install HAProxy on the proxy node.
2. Add the following content to the haproxy.cfg file in the /etc/haproxy/ directory:

   ......
   
   listen prestojdbc :9090
       mode tcp
       option tcplog
       balance source
       server presto-coodinator-1 emr-header-1:9090

3. Restart HAProxy.