小编Luc*_*kee的帖子

我在卡桑德拉有一张桌子，像这样：

CREATE TABLE vroc.sensor_data (
    dpnode text,
    year int,
    month int,
    day int,
    data_timestamp bigint,
    data_sensor text,
    dsnode text,
    data_quality double,
    data_value blob,
    PRIMARY KEY ((dpnode, year, month, day), data_timestamp, data_sensor, dsnode)
) 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', 'max_threshold' : 32, 'min_threshold' : 4 }
   AND compression …

我是 h2o 的初学者，我想知道 h2o 框架中是否有任何属性选择功能可以应用于 h2oframes 中？

我想将一个简单的Java函数转换为一个没有任何参数的lambda 8函数,然后调用它:

public int getMissing() {
  return 0;
}

如何将上面的内容转换为java8 lambda格式？

在以集群模式运行的spark应用程序中，出现以下异常。我知道某种原因是由于金刚砂问题。但是正如错误所言，它无法连接到节点。但是我确定该节点可用并且可以连接。谁能知道此错误的主要原因是什么以及如何解决？

17/10/31 17:10:54 ERROR ShuffleBlockFetcherIterator: Failed to get block(s) from AUPER01-02-10-12-0.prod.vroc.com.au:36787
java.io.IOException: Failed to connect to AUPER01-02-10-12-0.prod.vroc.com.au/192.168.11.22:36787
        at org.apache.spark.network.client.TransportClientFactory.createClient(TransportClientFactory.java:232)
        at org.apache.spark.network.client.TransportClientFactory.createClient(TransportClientFactory.java:182)
        at org.apache.spark.network.netty.NettyBlockTransferService$$anon$1.createAndStart(NettyBlockTransferService.scala:97)
        at org.apache.spark.network.shuffle.RetryingBlockFetcher.fetchAllOutstanding(RetryingBlockFetcher.java:141)
        at org.apache.spark.network.shuffle.RetryingBlockFetcher.access$200(RetryingBlockFetcher.java:43)
        at org.apache.spark.network.shuffle.RetryingBlockFetcher$1.run(RetryingBlockFetcher.java:171)
        at java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:511)
        at java.util.concurrent.FutureTask.run(FutureTask.java:266)
        at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1142)
        at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:617)
        at io.netty.util.concurrent.DefaultThreadFactory$DefaultRunnableDecorator.run(DefaultThreadFactory.java:144)
        at java.lang.Thread.run(Thread.java:745)
Caused by: io.netty.channel.AbstractChannel$AnnotatedConnectException: Connection refused: AUPER01-02-10-12-0.prod.vroc.com.au/192.168.11.22:36787
        at sun.nio.ch.SocketChannelImpl.checkConnect(Native Method)
        at sun.nio.ch.SocketChannelImpl.finishConnect(SocketChannelImpl.java:717)
        at io.netty.channel.socket.nio.NioSocketChannel.doFinishConnect(NioSocketChannel.java:257)
        at io.netty.channel.nio.AbstractNioChannel$AbstractNioUnsafe.finishConnect(AbstractNioChannel.java:291)
        at io.netty.channel.nio.NioEventLoop.processSelectedKey(NioEventLoop.java:631)
        at io.netty.channel.nio.NioEventLoop.processSelectedKeysOptimized(NioEventLoop.java:566)
        at io.netty.channel.nio.NioEventLoop.processSelectedKeys(NioEventLoop.java:480)
        at io.netty.channel.nio.NioEventLoop.run(NioEventLoop.java:442)
        at io.netty.util.concurrent.SingleThreadEventExecutor$2.run(SingleThreadEventExecutor.java:131)
        ... 2 more