From 53a6abfe6eaa663f00b38b2e7491673b9adfb635 Mon Sep 17 00:00:00 2001
From: Michael Stack <stack@apache.org>
Date: Mon, 31 Mar 2008 19:26:47 +0000
Subject: [PATCH] HBASE-550 EOF trying to read reconstruction log stops region
 deployment M  src/java/org/apache/hadoop/hbase/HStore.java     (Constructor)
 If an exception out of reconstructionLog method, log it and     keep going. 
 Presumption is that its result of a lack of HADOOP--1700.    
 (reconstructionLog): Check for empty log file.

git-svn-id: https://svn.apache.org/repos/asf/hadoop/hbase/trunk@643110 13f79535-47bb-0310-9956-ffa450edef68
---
 CHANGES.txt                                   |  1 +
 .../hadoop/hbase/regionserver/HStore.java     | 26 ++++++++++++++-----
 2 files changed, 20 insertions(+), 7 deletions(-)

diff --git a/CHANGES.txt b/CHANGES.txt
index 596c652bf4f..515a85b9eca 100644
--- a/CHANGES.txt
+++ b/CHANGES.txt
@@ -105,6 +105,7 @@ Hbase Change Log
    HBASE-529   RegionServer needs to recover if datanode goes down
    HBASE-456   Clearly state which ports need to be opened in order to run HBase
    HBASE-536   Remove MiniDFS startup from MiniHBaseCluster
+   HBASE-521   Improve client scanner interface
    
 Branch 0.1
 
diff --git a/src/java/org/apache/hadoop/hbase/regionserver/HStore.java b/src/java/org/apache/hadoop/hbase/regionserver/HStore.java
index d42d90bc3d4..03a9eaf8bca 100644
--- a/src/java/org/apache/hadoop/hbase/regionserver/HStore.java
+++ b/src/java/org/apache/hadoop/hbase/regionserver/HStore.java
@@ -44,6 +44,7 @@ import org.apache.hadoop.fs.FSDataInputStream;
 import org.apache.hadoop.fs.FSDataOutputStream;
 import org.apache.hadoop.fs.FileStatus;
 import org.apache.hadoop.fs.FileSystem;
+import org.apache.hadoop.fs.FileStatus;
 import org.apache.hadoop.fs.Path;
 import org.apache.hadoop.hbase.filter.RowFilterInterface;
 import org.apache.hadoop.hbase.io.ImmutableBytesWritable;
@@ -206,10 +207,7 @@ public class HStore implements HConstants {
     }
 
     if(LOG.isDebugEnabled()) {
-      LOG.debug("starting " + storeName +
-          ((reconstructionLog == null || !fs.exists(reconstructionLog)) ?
-          " (no reconstruction log)" :
-            " with reconstruction log: " + reconstructionLog.toString()));
+      LOG.debug("starting " + storeName);
     }
 
     // Go through the 'mapdir' and 'infodir' together, make sure that all 
@@ -236,7 +234,16 @@ public class HStore implements HConstants {
           this.maxSeqId);
     }
     
-    doReconstructionLog(reconstructionLog, maxSeqId);
+    try {
+      doReconstructionLog(reconstructionLog, maxSeqId);
+    } catch (IOException e) {
+      // Presume we got here because of some HDFS issue or because of a lack of
+      // HADOOP-1700; for now keep going but this is probably not what we want
+      // long term.  If we got here there has been data-loss
+      LOG.warn("Exception processing reconstruction log " + reconstructionLog +
+        " opening " + this.storeName +
+        " -- continuing.  Probably DATA LOSS!", e);
+    }
 
     // By default, we compact if an HStore has more than
     // MIN_COMMITS_FOR_COMPACTION map files
@@ -303,11 +310,16 @@ public class HStore implements HConstants {
   private void doReconstructionLog(final Path reconstructionLog,
     final long maxSeqID)
   throws UnsupportedEncodingException, IOException {
-    
     if (reconstructionLog == null || !fs.exists(reconstructionLog)) {
       // Nothing to do.
       return;
     }
+    // Check its not empty.
+    FileStatus[] stats = fs.listStatus(reconstructionLog);
+    if (stats == null || stats.length == 0) {
+      LOG.warn("Passed reconstruction log " + reconstructionLog + " is zero-length");
+      return;
+    }
     long maxSeqIdInLog = -1;
     TreeMap<HStoreKey, byte []> reconstructedCache =
       new TreeMap<HStoreKey, byte []>();
@@ -1691,4 +1703,4 @@ public class HStore implements HConstants {
       }
     }
   }
-}
\ No newline at end of file
+}