HDFS-16324. Fix error log in BlockManagerSafeMode (#3661)

Reviewed-by: tomscut <litao@bigo.sg>
Reviewed-by: Ayush Saxena <ayushsaxena@apache.org>
Signed-off-by: Akira Ajisaka <aajisaka@apache.org>

hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/server/blockmanagement/BlockManagerSafeMode.java

@@ -649,8 +649,8 @@ class BlockManagerSafeMode {
           DFSConfigKeys.DFS_NAMENODE_SAFEMODE_RECHECK_INTERVAL_DEFAULT);
       if (recheckInterval < 1) {
         LOG.warn("Invalid value for " +
-            DFSConfigKeys.DFS_NAMENODE_SAFEMODE_RECHECK_INTERVAL_DEFAULT +
-            ".Should be greater than 0, but is {}", recheckInterval);
+            DFSConfigKeys.DFS_NAMENODE_SAFEMODE_RECHECK_INTERVAL_KEY +
+            ". Should be greater than 0, but is {}", recheckInterval);
         recheckInterval = DFSConfigKeys.DFS_NAMENODE_SAFEMODE_RECHECK_INTERVAL_DEFAULT;
       }
       LOG.info("Using {} as SafeModeMonitor Interval", recheckInterval);

hadoop-hdfs-project/hadoop-hdfs/src/test/java/org/apache/hadoop/hdfs/server/blockmanagement/TestBlockManagerSafeMode.java

@@ -30,6 +30,7 @@ import org.apache.hadoop.hdfs.server.namenode.NameNode;
 import org.apache.hadoop.test.GenericTestUtils;
 import org.apache.hadoop.test.Whitebox;
 
+import org.assertj.core.api.Assertions;
 import org.junit.Before;
 import org.junit.Test;
 
@@ -242,6 +243,20 @@ public class TestBlockManagerSafeMode {
     assertTrue(content.contains("Using 3000 as SafeModeMonitor Interval"));
   }
 
+  @Test(timeout = 20000)
+  public void testCheckSafeMode10(){
+    Configuration conf = new HdfsConfiguration();
+    conf.setLong(DFSConfigKeys.DFS_NAMENODE_SAFEMODE_RECHECK_INTERVAL_KEY, -1);
+    GenericTestUtils.LogCapturer logs =
+            GenericTestUtils.LogCapturer.captureLogs(BlockManagerSafeMode.LOG);
+    BlockManagerSafeMode blockManagerSafeMode = new BlockManagerSafeMode(bm,
+            fsn, true, conf);
+    String content = logs.getOutput();
+    Assertions.assertThat(content).contains("Invalid value for " +
+            DFSConfigKeys.DFS_NAMENODE_SAFEMODE_RECHECK_INTERVAL_KEY +
+            ". Should be greater than 0, but is -1");
+  }
+
   /**
    * Test that the block safe increases up to block threshold.
    *