drop-Tabelle funktioniert nicht - com.datastax.driver.core

Question

Drop-Tabelle mit dem Datastax-Treiber für Cassandra scheint nicht zu funktionieren. create table works, aber drop table nicht und wirft keine Ausnahme. 1) Mache ich den Tropfen richtig? 2) Hat noch jemand dieses Verhalten gesehen?

In der Ausgabe können Sie sehen, dass die Tabelle erstellt und anscheinend gelöscht wird, da sie nicht in der zweiten Tabellenauflistung im ersten Lauf enthalten ist. Wenn ich die Verbindung jedoch wieder herstelle (zweiter Durchlauf), kommt es zu einer Ausnahme.

import java.util.Collection; 
import com.datastax.driver.core.*; 

public class Fail { 
    SimpleStatement createTableCQL = new SimpleStatement("create table test_table(testfield varchar primary key)"); 
    SimpleStatement dropTableCQL = new SimpleStatement("drop table test_table"); 
    Session session = null; 
    Cluster cluster = null; 

    public Fail() 
    { 
     System.out.println("First Run"); 
     this.run(); 
     System.out.println("Second Run"); 
     this.run(); 
    } 

    private void run() 
    { 
     try 
     { 
      cluster = Cluster.builder().addContactPoints("10.48.8.43 10.48.8.47 10.48.8.53") 
        .withCredentials("394016","394016") 
        .withQueryOptions(new QueryOptions().setConsistencyLevel(ConsistencyLevel.ALL)) 
        .build(); 
      session = cluster.connect("gid394016"); 
     } 
     catch(Exception e) 
     { 
      System.err.println(e.toString()); 
      System.exit(1); 
     } 

     //create the table 
     System.out.println("createTableCQL"); 
     this.session.execute(createTableCQL); 

     //list tables in the keyspace 
     System.out.println("Table list:"); 
     Collection<TableMetadata> results1 = cluster.getMetadata().getKeyspace("gid394016").getTables(); 
     for (TableMetadata tm : results1) 
     { 
      System.out.println(tm.toString()); 
     } 

     //drop the table 
     System.out.println("dropTableCQL"); 
     this.session.execute(dropTableCQL); 

     //list tables in the keyspace 
     System.out.println("Table list:"); 
     Collection<TableMetadata> results2 = cluster.getMetadata().getKeyspace("gid394016").getTables(); 
     for (TableMetadata tm : results2) 
     { 
      System.out.println(tm.toString()); 
     } 

     session.close(); 
     cluster.close();  
    } 

    public static void main(String[] args) { 
     new Fail(); 
    } 

} 

Console Ausgabe:

First Run 
[main] INFO com.datastax.driver.core.NettyUtil - Did not find Netty's native epoll transport in the classpath, defaulting to NIO. 
[main] INFO com.datastax.driver.core.policies.DCAwareRoundRobinPolicy - Using data-center name 'Cassandra' for DCAwareRoundRobinPolicy (if this is incorrect, please provide the correct datacenter name with DCAwareRoundRobinPolicy constructor) 
[main] INFO com.datastax.driver.core.Cluster - New Cassandra host /10.48.8.51:9042 added 
[main] INFO com.datastax.driver.core.Cluster - New Cassandra host /10.48.8.47:9042 added 
[main] INFO com.datastax.driver.core.Cluster - New Cassandra host /10.48.8.53:9042 added 
[main] INFO com.datastax.driver.core.Cluster - New Cassandra host /10.48.8.49:9042 added 
[main] INFO com.datastax.driver.core.Cluster - New Cassandra host 10.48.8.43 10.48.8.47 10.48.8.53/10.48.8.43:9042 added 
createTableCQL 
Table list: 
CREATE TABLE gid394016.test_table (testfield text, PRIMARY KEY (testfield)) WITH read_repair_chance = 0.0 AND dclocal_read_repair_chance = 0.1 AND gc_grace_seconds = 864000 AND bloom_filter_fp_chance = 0.01 AND caching = { 'keys' : 'ALL', 'rows_per_partition' : 'NONE' } AND comment = '' AND compaction = { 'class' : 'org.apache.cassandra.db.compaction.SizeTieredCompactionStrategy' } AND compression = { 'sstable_compression' : 'org.apache.cassandra.io.compress.LZ4Compressor' } AND default_time_to_live = 0 AND speculative_retry = '99.0PERCENTILE' AND min_index_interval = 128 AND max_index_interval = 2048; 
dropTableCQL 
Table list: 
Second Run 
[main] INFO com.datastax.driver.core.policies.DCAwareRoundRobinPolicy - Using data-center name 'Cassandra' for DCAwareRoundRobinPolicy (if this is incorrect, please provide the correct datacenter name with DCAwareRoundRobinPolicy constructor) 
[main] INFO com.datastax.driver.core.Cluster - New Cassandra host /10.48.8.51:9042 added 
[main] INFO com.datastax.driver.core.Cluster - New Cassandra host /10.48.8.47:9042 added 
[main] INFO com.datastax.driver.core.Cluster - New Cassandra host /10.48.8.53:9042 added 
[main] INFO com.datastax.driver.core.Cluster - New Cassandra host /10.48.8.49:9042 added 
[main] INFO com.datastax.driver.core.Cluster - New Cassandra host 10.48.8.43 10.48.8.47 10.48.8.53/10.48.8.43:9042 added 
createTableCQL 
Exception in thread "main" com.datastax.driver.core.exceptions.AlreadyExistsException: Table gid394016.test_table already exists 
    at com.datastax.driver.core.exceptions.AlreadyExistsException.copy(AlreadyExistsException.java:111) 
    at com.datastax.driver.core.DriverThrowables.propagateCause(DriverThrowables.java:37) 
    at com.datastax.driver.core.DefaultResultSetFuture.getUninterruptibly(DefaultResultSetFuture.java:217) 
    at com.datastax.driver.core.AbstractSession.execute(AbstractSession.java:54) 
    at com.bdcauto.cassandrachecks.Fail.run(Fail.java:38) 
    at com.bdcauto.cassandrachecks.Fail.<init>(Fail.java:17) 
    at com.bdcauto.cassandrachecks.Fail.main(Fail.java:65) 
Caused by: com.datastax.driver.core.exceptions.AlreadyExistsException: Table gid394016.test_table already exists 
    at com.datastax.driver.core.exceptions.AlreadyExistsException.copy(AlreadyExistsException.java:130) 
    at com.datastax.driver.core.Responses$Error.asException(Responses.java:118) 
    at com.datastax.driver.core.DefaultResultSetFuture.onSet(DefaultResultSetFuture.java:151) 
    at com.datastax.driver.core.RequestHandler.setFinalResult(RequestHandler.java:175) 
    at com.datastax.driver.core.RequestHandler.access$2500(RequestHandler.java:44) 
    at com.datastax.driver.core.RequestHandler$SpeculativeExecution.setFinalResult(RequestHandler.java:801) 
    at com.datastax.driver.core.RequestHandler$SpeculativeExecution.onSet(RequestHandler.java:617) 
    at com.datastax.driver.core.Connection$Dispatcher.channelRead0(Connection.java:1014) 
    at com.datastax.driver.core.Connection$Dispatcher.channelRead0(Connection.java:937) 
    at io.netty.channel.SimpleChannelInboundHandler.channelRead(SimpleChannelInboundHandler.java:105) 
    at io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:318) 
    at io.netty.channel.AbstractChannelHandlerContext.fireChannelRead(AbstractChannelHandlerContext.java:304) 
    at io.netty.handler.timeout.IdleStateHandler.channelRead(IdleStateHandler.java:266) 
    at io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:318) 
    at io.netty.channel.AbstractChannelHandlerContext.fireChannelRead(AbstractChannelHandlerContext.java:304) 
    at io.netty.handler.codec.MessageToMessageDecoder.channelRead(MessageToMessageDecoder.java:103) 
    at io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:318) 
    at io.netty.channel.AbstractChannelHandlerContext.fireChannelRead(AbstractChannelHandlerContext.java:304) 
    at io.netty.handler.codec.ByteToMessageDecoder.fireChannelRead(ByteToMessageDecoder.java:276) 
    at io.netty.handler.codec.ByteToMessageDecoder.channelRead(ByteToMessageDecoder.java:263) 
    at io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:318) 
    at io.netty.channel.AbstractChannelHandlerContext.fireChannelRead(AbstractChannelHandlerContext.java:304) 
    at io.netty.channel.DefaultChannelPipeline.fireChannelRead(DefaultChannelPipeline.java:846) 
    at io.netty.channel.nio.AbstractNioByteChannel$NioByteUnsafe.read(AbstractNioByteChannel.java:131) 
    at io.netty.channel.nio.NioEventLoop.processSelectedKey(NioEventLoop.java:511) 
    at io.netty.channel.nio.NioEventLoop.processSelectedKeysOptimized(NioEventLoop.java:468) 
    at io.netty.channel.nio.NioEventLoop.processSelectedKeys(NioEventLoop.java:382) 
    at io.netty.channel.nio.NioEventLoop.run(NioEventLoop.java:354) 
    at io.netty.util.concurrent.SingleThreadEventExecutor$2.run(SingleThreadEventExecutor.java:112) 
    at java.lang.Thread.run(Thread.java:745) 
Caused by: com.datastax.driver.core.exceptions.AlreadyExistsException: Table gid394016.test_table already exists 
    at com.datastax.driver.core.Responses$Error$1.decode(Responses.java:69) 
    at com.datastax.driver.core.Responses$Error$1.decode(Responses.java:37) 
    at com.datastax.driver.core.Message$ProtocolDecoder.decode(Message.java:230) 
    at com.datastax.driver.core.Message$ProtocolDecoder.decode(Message.java:221) 
    at io.netty.handler.codec.MessageToMessageDecoder.channelRead(MessageToMessageDecoder.java:89) 
    ... 14 more 

Answer 1

Sie diesen Code mit der Tabelle in der Datenbank vorhanden laufen und das ist, warum Sie bekommen die „bereits vorhanden“ Fehler. Bitte verbinden Sie sich mit Cqlsh mit der Datenbank und überprüfen Sie das selbst. Erstellen, Ändern und Löschen von Tabellenanweisungen werden asynchron im gesamten Cluster weitergegeben. Auch wenn Sie eine Antwort vom Koordinator erhalten, müssen Sie noch auf schema agreement warten.