YARN-2905. AggregatedLogsBlock page can infinitely loop if the aggregated log file is corrupted. Contributed by Varun Saxena

hadoop-yarn-project/CHANGES.txt

@@ -155,6 +155,9 @@ Release 2.7.0 - UNRELEASED
     YARN-2906. CapacitySchedulerPage shows HTML tags for a queue's Active Users.
     (Jason Lowe via jianhe)
 
+    YARN-2905. AggregatedLogsBlock page can infinitely loop if the aggregated
+    log file is corrupted (Varun Saxena via jlowe)
+
 Release 2.6.0 - 2014-11-18
 
   INCOMPATIBLE CHANGES

hadoop-yarn-project/hadoop-yarn/hadoop-yarn-common/src/main/java/org/apache/hadoop/yarn/logaggregation/AggregatedLogFormat.java

@@ -801,6 +801,10 @@ public class AggregatedLogFormat {
       return currentLogData.skip(n);
     }
 
+    public int read() throws IOException {
+      return currentLogData.read();
+    }
+
     public int read(byte[] buf, int off, int len) throws IOException {
       return currentLogData.read(buf, off, len);
     }

hadoop-yarn-project/hadoop-yarn/hadoop-yarn-common/src/main/java/org/apache/hadoop/yarn/webapp/log/AggregatedLogsBlock.java

@@ -231,8 +231,14 @@ public class AggregatedLogsBlock extends HtmlBlock {
         long totalSkipped = 0;
         while (totalSkipped < start) {
           long ret = logReader.skip(start - totalSkipped);
-          if (ret < 0) {
-            throw new IOException( "Premature EOF from container log");
+          if (ret == 0) {
+            //Read one byte
+            int nextByte = logReader.read();
+            // Check if we have reached EOF
+            if (nextByte == -1) {
+              throw new IOException( "Premature EOF from container log");
+            }
+            ret = 1;
           }
           totalSkipped += ret;
         }