一个kylin build job执行到第三步Extract Fact Table Distinct Columns时报错：
2017-05-24 20:04:07,930 ERROR [pool-9-thread-3] common.MapReduceExecutable:127 : error execute MapReduceExecutable{id=a79c9625-39aa-4f17-8015-73b640558425-02, name=Extra
ct Fact Table Distinct Columns, state=RUNNING}
java.lang.IllegalStateException
at org.apache.kylin.engine.mr.steps.FactDistinctColumnsJob.run(FactDistinctColumnsJob.java:98)
at org.apache.kylin.engine.mr.MRUtil.runMRJob(MRUtil.java:92)
at org.apache.kylin.engine.mr.common.MapReduceExecutable.doWork(MapReduceExecutable.java:120)
at org.apache.kylin.job.execution.AbstractExecutable.execute(AbstractExecutable.java:113)
at org.apache.kylin.job.execution.DefaultChainedExecutable.doWork(DefaultChainedExecutable.java:57)
at org.apache.kylin.job.execution.AbstractExecutable.execute(AbstractExecutable.java:113)
at org.apache.kylin.job.impl.threadpool.DefaultScheduler$JobRunner.run(DefaultScheduler.java:136)
at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1142)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:617)
at java.lang.Thread.run(Thread.java:745)
解决方案：找到执行这个build任务的kylin实例，reload metadata或重启kylin服务（不推荐），然后重新build.
原因分析：执行build的job server内存中的Meta没有被更新，使用了缓存中的Meta执行build导致。