Synchronization issue on mapStorageCapacity

[PHILO-HE]

2018-03-08 01:20:00,004 ERROR org.smartdata.hdfs.metric.fetcher.StorageInfoSampler.run 124: Storage info sampling task error:
java.lang.NullPointerException
at org.smartdata.metastore.MetaStore.getStorageCapacity(MetaStore.java:433)
at org.smartdata.hdfs.metric.fetcher.StorageInfoSampler$InfoSamplingTask.run(StorageInfoSampler.java:111)
at java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:511)
at java.util.concurrent.FutureTask.runAndReset(FutureTask.java:308)
at java.util.concurrent.ScheduledThreadPoolExecutor$ScheduledFutureTask.access$301(ScheduledThreadPoolExecutor.java:180)
at java.util.concurrent.ScheduledThreadPoolExecutor$ScheduledFutureTask.run(ScheduledThreadPoolExecutor.java:294)
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:748)