Question

我正在使用Cassandra存储我的应用程序发生的所有事件.6个月后它有超过数百万的数据。

我在阅读cassandra

中的所有记录时遇到以下错误

CLI -

cqlsh> use abc;
cqlsh:abc> select count(*) from interaction;
OperationTimedOut: errors={}, last_host=localhost

从春季数据（使用允许过滤）

Caused by: com.datastax.driver.core.exceptions.ReadTimeoutException: Cassandra timeout during read query at consistency ONE (1 responses were required but only 0 replica responded)
    at com.datastax.driver.core.exceptions.ReadTimeoutException.copy(ReadTimeoutException.java:69)
    at com.datastax.driver.core.DefaultResultSetFuture.extractCauseFromExecutionException(DefaultResultSetFuture.java:256)
    at com.datastax.driver.core.DefaultResultSetFuture.getUninterruptibly(DefaultResultSetFuture.java:172)
    at com.datastax.driver.core.AbstractSession.execute(AbstractSession.java:52)
    at com.datastax.driver.core.AbstractSession.execute(AbstractSession.java:36)
    at com.germinait.replica.CassandraTransfer.startTransfer(CassandraTransfer.java:43)
    at com.germinait.replica.DemoApplication.run(DemoApplication.java:22)
    at org.springframework.boot.SpringApplication.runCommandLineRunners(SpringApplication.java:673)
    ... 5 more
Caused by: com.datastax.driver.core.exceptions.ReadTimeoutException: Cassandra timeout during read query at consistency ONE (1 responses were required but only 0 replica responded)
    at com.datastax.driver.core.exceptions.ReadTimeoutException.copy(ReadTimeoutException.java:69)
    at com.datastax.driver.core.Responses$Error.asException(Responses.java:94)
    at com.datastax.driver.core.DefaultResultSetFuture.onSet(DefaultResultSetFuture.java:108)
    at com.datastax.driver.core.RequestHandler.setFinalResult(RequestHandler.java:235)
    at com.datastax.driver.core.RequestHandler.onSet(RequestHandler.java:379)
    at com.datastax.driver.core.Connection$Dispatcher.messageReceived(Connection.java:584)
    at org.jboss.netty.channel.SimpleChannelUpstreamHandler.handleUpstream(SimpleChannelUpstreamHandler.java:70)
    at org.jboss.netty.channel.DefaultChannelPipeline.sendUpstream(DefaultChannelPipeline.java:564)
    at org.jboss.netty.channel.DefaultChannelPipeline$DefaultChannelHandlerContext.sendUpstream(DefaultChannelPipeline.java:791)
    at org.jboss.netty.channel.Channels.fireMessageReceived(Channels.java:296)
    at org.jboss.netty.handler.codec.oneone.OneToOneDecoder.handleUpstream(OneToOneDecoder.java:70)
    at org.jboss.netty.channel.DefaultChannelPipeline.sendUpstream(DefaultChannelPipeline.java:564)
    at org.jboss.netty.channel.DefaultChannelPipeline$DefaultChannelHandlerContext.sendUpstream(DefaultChannelPipeline.java:791)
    at org.jboss.netty.channel.Channels.fireMessageReceived(Channels.java:296)
    at org.jboss.netty.handler.codec.frame.FrameDecoder.unfoldAndFireMessageReceived(FrameDecoder.java:462)
    at org.jboss.netty.handler.codec.frame.FrameDecoder.callDecode(FrameDecoder.java:443)
    at org.jboss.netty.handler.codec.frame.FrameDecoder.messageReceived(FrameDecoder.java:303)
    at org.jboss.netty.channel.SimpleChannelUpstreamHandler.handleUpstream(SimpleChannelUpstreamHandler.java:70)
    at org.jboss.netty.channel.DefaultChannelPipeline.sendUpstream(DefaultChannelPipeline.java:564)
    at org.jboss.netty.channel.DefaultChannelPipeline.sendUpstream(DefaultChannelPipeline.java:

我不确定如何阅读大量数据。

让我知道如何使用spring-data或其他替代方法来读取这些大数据。

Answer 1

更改并查看驱动程序读取超时

https://datastax.github.io/java-driver/manual/socket_options/

Cluster cluster = Cluster.builder()
    .addContactPoint("127.0.0.1")
    .withSocketOptions(
            new SocketOptions()
                    .setConnectTimeoutMillis(2000))
    .build();

更改Cassandra服务器配置以允许大量读写

read_request_timeout_in_ms，range_request_timeout_in_ms， write_request_timeout_in_ms，cas_contention_timeout_in_ms， truncate_request_timeout_in_ms

另外，请查看此答案以获取更多信息。

Cassandra read timeout

Answer 2

如果你想知道一个表包含多少行，你可以有一个计数器表，它在插入记录时递增，在删除行时递减。

阅读超过数百万的cassandra记录

2 个答案: