在我们的单个节点Cassadra部署之一中，有这个表模式：
CREATE table CTS_SVC_PT_INT_READ (
svc_pt_id bigint,
meas_type_id bigint,
value double,
flags bigint,
read_time timestamp,
last_upd_time timestamp,
PRIMARY KEY (svc_pt_id, meas_type_id, read_time)
) WITH CLUSTERING ORDER BY (meas_type_id ASC, read_time DESC)
AND compaction = {
'class': 'org.apache.cassandra.db.compaction.DateTieredCompactionStrategy',
'timestamp_resolution': 'MILLISECONDS',
'base_time_seconds': '3600',
'max_sstable_age_days': '365'
};
在通过Java客户端查询select distinct svc_pt_id from cts.CTS_SVC_PT_INT_READ时，它失败并出现异常：
select distinct svc_pt_id from cts.CTS_SVC_PT_INT_READ com.datastax.driver.core.exceptions.ReadFailureException: Cassandra failure during read query at consistency LOCAL_ONE (1 responses were required but only 0 replica responded, 1 failed)
java.util.concurrent.ExecutionException: com.datastax.driver.core.exceptions.ReadFailureException: Cassandra failure during read query at consistency LOCAL_ONE (1 responses were required but only 0 replica responded, 1 failed)
at com.google.common.util.concurrent.AbstractFuture$Sync.getValue(AbstractFuture.java:299)
at com.google.common.util.concurrent.AbstractFuture$Sync.get(AbstractFuture.java:286)
at com.google.common.util.concurrent.AbstractFuture.get(AbstractFuture.java:116)
at rx.internal.operators.OnSubscribeToObservableFuture$ToObservableFuture.call(OnSubscribeToObservableFuture.java:74)
at rx.internal.operators.OnSubscribeToObservableFuture$ToObservableFuture.call(OnSubscribeToObservableFuture.java:43)
at rx.Observable.unsafeSubscribe(Observable.java:8314)
at rx.internal.operators.OperatorSubscribeOn$1.call(OperatorSubscribeOn.java:94)
at rx.internal.schedulers.ScheduledAction.run(ScheduledAction.java:55)
at java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:511)
at java.util.concurrent.FutureTask.run(FutureTask.java:266)
at java.util.concurrent.ScheduledThreadPoolExecutor$ScheduledFutureTask.access$201(ScheduledThreadPoolExecutor.java:180)
at java.util.concurrent.ScheduledThreadPoolExecutor$ScheduledFutureTask.run(ScheduledThreadPoolExecutor.java:293)
at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1142)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:617)
at java.lang.Thread.run(Thread.java:745)
Caused by: com.datastax.driver.core.exceptions.ReadFailureException: Cassandra failure during read query at consistency LOCAL_ONE (1 responses were required but only 0 replica responded, 1 failed)
at com.datastax.driver.core.exceptions.ReadFailureException.copy(ReadFailureException.java:95)
at com.datastax.driver.core.Responses$Error.asException(Responses.java:128)
at com.datastax.driver.core.DefaultResultSetFuture.onSet(DefaultResultSetFuture.java:179)
at com.datastax.driver.core.RequestHandler.setFinalResult(RequestHandler.java:184)
at com.datastax.driver.core.RequestHandler.access$2500(RequestHandler.java:43)
at com.datastax.driver.core.RequestHandler$SpeculativeExecution.setFinalResult(RequestHandler.java:798)
at com.datastax.driver.core.RequestHandler$SpeculativeExecution.onSet(RequestHandler.java:617)
at com.datastax.driver.core.Connection$Dispatcher.channelRead0(Connection.java:1005)
at com.datastax.driver.core.Connection$Dispatcher.channelRead0(Connection.java:928)
at io.netty.channel.SimpleChannelInboundHandler.channelRead(SimpleChannelInboundHandler.java:105)
at io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:318)
at io.netty.channel.AbstractChannelHandlerContext.fireChannelRead(AbstractChannelHandlerContext.java:304)
at io.netty.handler.timeout.IdleStateHandler.channelRead(IdleStateHandler.java:266)
at io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:318)
at io.netty.channel.AbstractChannelHandlerContext.fireChannelRead(AbstractChannelHandlerContext.java:304)
at io.netty.handler.codec.MessageToMessageDecoder.channelRead(MessageToMessageDecoder.java:103)
at io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:318)
at io.netty.channel.AbstractChannelHandlerContext.fireChannelRead(AbstractChannelHandlerContext.java:304)
at io.netty.handler.codec.ByteToMessageDecoder.fireChannelRead(ByteToMessageDecoder.java:276)
at io.netty.handler.codec.ByteToMessageDecoder.callDecode(ByteToMessageDecoder.java:354)
at io.netty.handler.codec.ByteToMessageDecoder.channelRead(ByteToMessageDecoder.java:244)
at io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:318)
at io.netty.channel.AbstractChannelHandlerContext.fireChannelRead(AbstractChannelHandlerContext.java:304)
at io.netty.channel.DefaultChannelPipeline.fireChannelRead(DefaultChannelPipeline.java:846)
at io.netty.channel.nio.AbstractNioByteChannel$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$2.run(SingleThreadEventExecutor.java:112)
... 1 more
Caused by: com.datastax.driver.core.exceptions.ReadFailureException: Cassandra failure during read query at consistency LOCAL_ONE (1 responses were required but only 0 replica responded, 1 failed)
at com.datastax.driver.core.Responses$Error$1.decode(Responses.java:76)
at com.datastax.driver.core.Responses$Error$1.decode(Responses.java:37)
at com.datastax.driver.core.Message$ProtocolDecoder.decode(Message.java:266)
at com.datastax.driver.core.Message$ProtocolDecoder.decode(Message.java:246)
at io.netty.handler.codec.MessageToMessageDecoder.channelRead(MessageToMessageDecoder.java:89)
... 15 more
如果我通过cqlsh发出这个cql命令，我会看到同样的错误。是由于ReadTimeOut问题还是其他原因？
答案 0 :(得分：1)
＆＃34; ReadFailureException：Cassandra失败... 0副本响应，1失败）＆＃34;表示失败，而不是超时。您可以通过查看服务器上的cassandra日志来了解更多信息。