From ec5a859b92f2f7177801f7b686759362172dc6c3 Mon Sep 17 00:00:00 2001
From: Andrew Purtell <apurtell@apache.org>
Date: Fri, 1 Aug 2014 17:18:01 -0700
Subject: [PATCH] HBASE-11650 Write hbase.id to a temporary location and move
 into place

---
 .../org/apache/hadoop/hbase/util/FSUtils.java | 21 +++++++++++++++----
 1 file changed, 17 insertions(+), 4 deletions(-)

diff --git a/hbase-server/src/main/java/org/apache/hadoop/hbase/util/FSUtils.java b/hbase-server/src/main/java/org/apache/hadoop/hbase/util/FSUtils.java
index fb00cf55021..53f5874980f 100644
--- a/hbase-server/src/main/java/org/apache/hadoop/hbase/util/FSUtils.java
+++ b/hbase-server/src/main/java/org/apache/hadoop/hbase/util/FSUtils.java
@@ -786,15 +786,28 @@ public abstract class FSUtils {
       int wait) throws IOException {
     while (true) {
       try {
-        Path filePath = new Path(rootdir, HConstants.CLUSTER_ID_FILE_NAME);
-        FSDataOutputStream s = fs.create(filePath);
+        Path idFile = new Path(rootdir, HConstants.CLUSTER_ID_FILE_NAME);
+        Path tempIdFile = new Path(rootdir, HConstants.HBASE_TEMP_DIRECTORY +
+          Path.SEPARATOR + HConstants.CLUSTER_ID_FILE_NAME);
+        // Write the id file to a temporary location
+        FSDataOutputStream s = fs.create(tempIdFile);
         try {
           s.write(clusterId.toByteArray());
-        } finally {
           s.close();
+          s = null;
+          // Move the temporary file to its normal location. Throw an IOE if
+          // the rename failed
+          if (!fs.rename(tempIdFile, idFile)) {
+            throw new IOException("Unable to move temp version file to " + idFile);
+          }
+        } finally {
+          // Attempt to close the stream if still open on the way out
+          try {
+            if (s != null) s.close();
+          } catch (IOException ignore) { }
         }
         if (LOG.isDebugEnabled()) {
-          LOG.debug("Created cluster ID file at " + filePath.toString() + " with ID: " + clusterId);
+          LOG.debug("Created cluster ID file at " + idFile.toString() + " with ID: " + clusterId);
         }
         return;
       } catch (IOException ioe) {