From 8458ced11e5b6690a41593c247c1190bf3f31c0b Mon Sep 17 00:00:00 2001
From: Mukul Kumar Singh <msingh@apache.org>
Date: Sat, 9 Mar 2019 22:46:20 +0530
Subject: [PATCH] HDDS-1238. Fix Ratis Snapshot creation error if the snapshot
 file already exists in ContainerStateMachine. Contributed by Shashikant
 Banerjee.

---
 .../server/ratis/ContainerStateMachine.java       | 15 ++++-----------
 1 file changed, 4 insertions(+), 11 deletions(-)

diff --git a/hadoop-hdds/container-service/src/main/java/org/apache/hadoop/ozone/container/common/transport/server/ratis/ContainerStateMachine.java b/hadoop-hdds/container-service/src/main/java/org/apache/hadoop/ozone/container/common/transport/server/ratis/ContainerStateMachine.java
index 0fc2d0d99b..7caf0c2190 100644
--- a/hadoop-hdds/container-service/src/main/java/org/apache/hadoop/ozone/container/common/transport/server/ratis/ContainerStateMachine.java
+++ b/hadoop-hdds/container-service/src/main/java/org/apache/hadoop/ozone/container/common/transport/server/ratis/ContainerStateMachine.java
@@ -249,20 +249,13 @@ public void persistContainerSet(OutputStream out) throws IOException {
   public long takeSnapshot() throws IOException {
     TermIndex ti = getLastAppliedTermIndex();
     LOG.info("Taking snapshot at termIndex:" + ti);
-    if (ti != null) {
+    if (ti != null && ti.getIndex() != RaftServerConstants.INVALID_LOG_INDEX) {
       final File snapshotFile =
           storage.getSnapshotFile(ti.getTerm(), ti.getIndex());
       LOG.info("Taking a snapshot to file {}", snapshotFile);
-      try {
-        //TODO: For now, just create the file to save the term index,
-        boolean created = snapshotFile.createNewFile();
-        if (!created) {
-          throw new IOException("Failed to create ratis snapshot file");
-        }
-        try (FileOutputStream fos = new FileOutputStream(snapshotFile)) {
-          persistContainerSet(fos);
-        }
-      } catch(IOException ioe) {
+      try (FileOutputStream fos = new FileOutputStream(snapshotFile)) {
+        persistContainerSet(fos);
+      } catch (IOException ioe) {
         LOG.warn("Failed to write snapshot file \"" + snapshotFile
             + "\", last applied index=" + ti);
         throw ioe;