Error stack as fllow:

2017-07-10T08:41:36,134 ERROR [task-runner-0-priority-0] io.druid.indexing.overlord.ThreadPoolTaskRunner - Exception while running task[HadoopIndexTask{id=index_hadoop_pageviews_2017-07-10T08:40:32.650Z, type=index_hadoop, dataSource=pageviews}]
java.lang.RuntimeException: java.lang.reflect.InvocationTargetException
	at com.google.common.base.Throwables.propagate(Throwables.java:160) ~[guava-16.0.1.jar:?]
	at io.druid.indexing.common.task.HadoopTask.invokeForeignLoader(HadoopTask.java:204) ~[druid-indexing-service-0.9.2.2.6.0.3-8.jar:0.9.2.2.6.0.3-8]
	at io.druid.indexing.common.task.HadoopIndexTask.run(HadoopIndexTask.java:208) ~[druid-indexing-service-0.9.2.2.6.0.3-8.jar:0.9.2.2.6.0.3-8]
	at io.druid.indexing.overlord.ThreadPoolTaskRunner$ThreadPoolTaskRunnerCallable.call(ThreadPoolTaskRunner.java:436) [druid-indexing-service-0.9.2.2.6.0.3-8.jar:0.9.2.2.6.0.3-8]
	at io.druid.indexing.overlord.ThreadPoolTaskRunner$ThreadPoolTaskRunnerCallable.call(ThreadPoolTaskRunner.java:408) [druid-indexing-service-0.9.2.2.6.0.3-8.jar:0.9.2.2.6.0.3-8]
	at java.util.concurrent.FutureTask.run(FutureTask.java:266) [?:1.8.0_131]
	at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1142) [?:1.8.0_131]
	at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:617) [?:1.8.0_131]
	at java.lang.Thread.run(Thread.java:748) [?:1.8.0_131]
Caused by: java.lang.reflect.InvocationTargetException
	at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) ~[?:1.8.0_131]
	at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62) ~[?:1.8.0_131]
	at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43) ~[?:1.8.0_131]
	at java.lang.reflect.Method.invoke(Method.java:498) ~[?:1.8.0_131]
	at io.druid.indexing.common.task.HadoopTask.invokeForeignLoader(HadoopTask.java:201) ~[druid-indexing-service-0.9.2.2.6.0.3-8.jar:0.9.2.2.6.0.3-8]
	... 7 more
Caused by: java.lang.RuntimeException: java.lang.RuntimeException: No buckets?? seems there is no data to index.
	at io.druid.indexer.IndexGeneratorJob.run(IndexGeneratorJob.java:215) ~[druid-indexing-hadoop-0.9.2.2.6.0.3-8.jar:0.9.2.2.6.0.3-8]
	at io.druid.indexer.JobHelper.runJobs(JobHelper.java:349) ~[druid-indexing-hadoop-0.9.2.2.6.0.3-8.jar:0.9.2.2.6.0.3-8]
	at io.druid.indexer.HadoopDruidIndexerJob.run(HadoopDruidIndexerJob.java:94) ~[druid-indexing-hadoop-0.9.2.2.6.0.3-8.jar:0.9.2.2.6.0.3-8]
	at io.druid.indexing.common.task.HadoopIndexTask$HadoopIndexGeneratorInnerProcessing.runTask(HadoopIndexTask.java:261) ~[druid-indexing-service-0.9.2.2.6.0.3-8.jar:0.9.2.2.6.0.3-8]
	at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) ~[?:1.8.0_131]
	at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62) ~[?:1.8.0_131]
	at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43) ~[?:1.8.0_131]
	at java.lang.reflect.Method.invoke(Method.java:498) ~[?:1.8.0_131]
	at io.druid.indexing.common.task.HadoopTask.invokeForeignLoader(HadoopTask.java:201) ~[druid-indexing-service-0.9.2.2.6.0.3-8.jar:0.9.2.2.6.0.3-8]
	... 7 more
Caused by: java.lang.RuntimeException: No buckets?? seems there is no data to index.
	at io.druid.indexer.IndexGeneratorJob.run(IndexGeneratorJob.java:176) ~[druid-indexing-hadoop-0.9.2.2.6.0.3-8.jar:0.9.2.2.6.0.3-8]
	at io.druid.indexer.JobHelper.runJobs(JobHelper.java:349) ~[druid-indexing-hadoop-0.9.2.2.6.0.3-8.jar:0.9.2.2.6.0.3-8]
	at io.druid.indexer.HadoopDruidIndexerJob.run(HadoopDruidIndexerJob.java:94) ~[druid-indexing-hadoop-0.9.2.2.6.0.3-8.jar:0.9.2.2.6.0.3-8]
	at io.druid.indexing.common.task.HadoopIndexTask$HadoopIndexGeneratorInnerProcessing.runTask(HadoopIndexTask.java:261) ~[druid-indexing-service-0.9.2.2.6.0.3-8.jar:0.9.2.2.6.0.3-8]
	at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) ~[?:1.8.0_131]
	at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62) ~[?:1.8.0_131]
	at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43) ~[?:1.8.0_131]
	at java.lang.reflect.Method.invoke(Method.java:498) ~[?:1.8.0_131]
	at io.druid.indexing.common.task.HadoopTask.invokeForeignLoader(HadoopTask.java:201) ~[druid-indexing-service-0.9.2.2.6.0.3-8.jar:0.9.2.2.6.0.3-8]
	... 7 more

From this, we can see the abnormal keywords:

No buckets?? seems there is no data to index.

Usually, my solution to the problem is Baidu first, github later, and then can not solve only look at the source code.

Because Druid is not popular in China, Baidu has no effect, and then to druid's github, search the above keywords, get a similar issue:

https://github.com/druid-io/druid/issues/3259

This issue did not solve the problem, but it gave me the idea to solve the problem: modify the timezone!

So I first looked at the system's timezone, which is CST, and the time is normal.

Then we observed the druid log and found that the druid log differed from the system time by 8 hours.

So in ambari, look up the druid configuration associated with timezone and find that the following attributes are related to timezone:

- druid.broker.jvm.opts

- druid.coordinator.jvm.opts

- druid.historical.jvm.opts

- druid.middlemanager.jvm.opts

- druid.overlord.jvm.opts

-druid.router.jvm.opts

-druid.indexer.runner.javaOpts

druid uses UTC by default. I found that there is an 8-hour difference between log and system time, so I changed it to UTC+8, and built it successfully! __________