From 6c78d4e6a635283f52bd8b2b4fc7cc14baaa23ff Mon Sep 17 00:00:00 2001
From: Jim Kellerman <jimk@apache.org>
Date: Fri, 23 Jan 2009 23:09:37 +0000
Subject: [PATCH] HBASE-1148  Always flush HLog on root or meta region updates

git-svn-id: https://svn.apache.org/repos/asf/hadoop/hbase/trunk@737241 13f79535-47bb-0310-9956-ffa450edef68
---
 CHANGES.txt                                     |  1 +
 .../apache/hadoop/hbase/regionserver/HLog.java  | 17 +++++++++--------
 .../hadoop/hbase/regionserver/HRegion.java      |  3 ++-
 .../hadoop/hbase/regionserver/TestHLog.java     |  4 ++--
 4 files changed, 14 insertions(+), 11 deletions(-)

diff --git a/CHANGES.txt b/CHANGES.txt
index 6cea83ff4e9..0c36bcf991b 100644
--- a/CHANGES.txt
+++ b/CHANGES.txt
@@ -10,6 +10,7 @@ Release 0.20.0 - Unreleased
    HBASE-1138  Test that readers opened after a sync can see all data up to the
                sync (temporary until HADOOP-4379 is resolved)
    HBASE-1121  Cluster confused about where -ROOT- is
+   HBASE-1148  Always flush HLog on root or meta region updates
 
   IMPROVEMENTS
    HBASE-1089  Add count of regions on filesystem to master UI; add percentage
diff --git a/src/java/org/apache/hadoop/hbase/regionserver/HLog.java b/src/java/org/apache/hadoop/hbase/regionserver/HLog.java
index fbd2f4a26ab..80edb34d531 100644
--- a/src/java/org/apache/hadoop/hbase/regionserver/HLog.java
+++ b/src/java/org/apache/hadoop/hbase/regionserver/HLog.java
@@ -455,13 +455,12 @@ public class HLog implements HConstants, Syncable {
    *
    * @param regionName
    * @param tableName
-   * @param row
-   * @param columns
-   * @param timestamp
+   * @param edits
+   * @param sync
    * @throws IOException
    */
   void append(byte [] regionName, byte [] tableName,
-      TreeMap<HStoreKey, byte[]> edits)
+      TreeMap<HStoreKey, byte[]> edits, boolean sync)
   throws IOException {
     if (closed) {
       throw new IOException("Cannot append; log is closed");
@@ -482,7 +481,7 @@ public class HLog implements HConstants, Syncable {
           new HLogKey(regionName, tableName, key.getRow(), seqNum[counter++]);
         HLogEdit logEdit =
           new HLogEdit(key.getColumn(), es.getValue(), key.getTimestamp());
-       doWrite(logKey, logEdit);
+       doWrite(logKey, logEdit, sync);
 
         this.numEntries++;
       }
@@ -520,10 +519,11 @@ public class HLog implements HConstants, Syncable {
     }
   }
   
-  private void doWrite(HLogKey logKey, HLogEdit logEdit) throws IOException {
+  private void doWrite(HLogKey logKey, HLogEdit logEdit, boolean sync)
+  throws IOException {
     try {
       this.writer.append(logKey, logEdit);
-      if (++unflushedEntries >= flushlogentries) {
+      if (sync || ++unflushedEntries >= flushlogentries) {
         sync();
       }
     } catch (IOException e) {
@@ -569,7 +569,8 @@ public class HLog implements HConstants, Syncable {
       }
 
       HLogKey logKey = new HLogKey(regionName, tableName, row, seqNum);
-      doWrite(logKey, logEdit);
+      boolean sync = regionInfo.isMetaRegion() || regionInfo.isRootRegion();
+      doWrite(logKey, logEdit, sync);
       this.numEntries++;
       updateLock.notifyAll();
     }
diff --git a/src/java/org/apache/hadoop/hbase/regionserver/HRegion.java b/src/java/org/apache/hadoop/hbase/regionserver/HRegion.java
index 9d65a675e3f..01b786f3947 100644
--- a/src/java/org/apache/hadoop/hbase/regionserver/HRegion.java
+++ b/src/java/org/apache/hadoop/hbase/regionserver/HRegion.java
@@ -1707,7 +1707,8 @@ public class HRegion implements HConstants {
     try {
       if (writeToWAL) {
         this.log.append(regionInfo.getRegionName(),
-          regionInfo.getTableDesc().getName(), updatesByColumn);
+          regionInfo.getTableDesc().getName(), updatesByColumn,
+          (regionInfo.isMetaRegion() || regionInfo.isRootRegion()));
       }
       long size = 0;
       for (Map.Entry<HStoreKey, byte[]> e: updatesByColumn.entrySet()) {
diff --git a/src/test/org/apache/hadoop/hbase/regionserver/TestHLog.java b/src/test/org/apache/hadoop/hbase/regionserver/TestHLog.java
index 04bb9d3b63b..26cc9915b83 100644
--- a/src/test/org/apache/hadoop/hbase/regionserver/TestHLog.java
+++ b/src/test/org/apache/hadoop/hbase/regionserver/TestHLog.java
@@ -77,7 +77,7 @@ public class TestHLog extends HBaseTestCase implements HConstants {
             byte [] column = Bytes.toBytes(Integer.toString(j));
             edit.put(new HStoreKey(rowName, column, System.currentTimeMillis()),
               column);
-            log.append(Bytes.toBytes(Integer.toString(i)), tableName, edit);
+            log.append(Bytes.toBytes(Integer.toString(i)), tableName, edit, false);
           }
         }
         log.rollWriter();
@@ -110,7 +110,7 @@ public class TestHLog extends HBaseTestCase implements HConstants {
         cols.put(new HStoreKey(row, Bytes.toBytes(Integer.toString(i)), timestamp),
             new byte[] { (byte)(i + '0') });
       }
-      log.append(regionName, tableName, cols);
+      log.append(regionName, tableName, cols, false);
       long logSeqId = log.startCacheFlush();
       log.completeCacheFlush(regionName, tableName, logSeqId);
       log.close();