diff --git a/hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/server/datanode/checker/ThrottledAsyncChecker.java b/hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/server/datanode/checker/ThrottledAsyncChecker.java index 88444539337..032379a4d12 100644 --- a/hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/server/datanode/checker/ThrottledAsyncChecker.java +++ b/hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/server/datanode/checker/ThrottledAsyncChecker.java @@ -123,8 +123,8 @@ public class ThrottledAsyncChecker implements AsyncChecker { return Optional.empty(); } - if (completedChecks.containsKey(target)) { - final LastCheckResult result = completedChecks.get(target); + final LastCheckResult result = completedChecks.get(target); + if (result != null) { final long msSinceLastCheck = timer.monotonicNow() - result.completedAt; if (msSinceLastCheck < minMsBetweenChecks) { LOG.debug("Skipped checking {}. Time since last check {}ms " +