From 7943b31c29750610a388788a279f4d90e47c849c Mon Sep 17 00:00:00 2001
From: Jim Brennan <jbrennan@apache.org>
Date: Thu, 28 Jan 2021 16:47:52 +0000
Subject: [PATCH] [HDFS-10498] Intermittent test failure
 TestSnapshotFileLength.testSnapshotFileLength. Contributed by Jim Brennan.

(cherry picked from commit 6184ab07f670c181d1fda99e76729e920fff287e)
---
 .../hdfs/server/namenode/snapshot/TestSnapshotFileLength.java    | 1 +
 1 file changed, 1 insertion(+)

diff --git a/hadoop-hdfs-project/hadoop-hdfs/src/test/java/org/apache/hadoop/hdfs/server/namenode/snapshot/TestSnapshotFileLength.java b/hadoop-hdfs-project/hadoop-hdfs/src/test/java/org/apache/hadoop/hdfs/server/namenode/snapshot/TestSnapshotFileLength.java
index 90e499d8a35..814da03559b 100644
--- a/hadoop-hdfs-project/hadoop-hdfs/src/test/java/org/apache/hadoop/hdfs/server/namenode/snapshot/TestSnapshotFileLength.java
+++ b/hadoop-hdfs-project/hadoop-hdfs/src/test/java/org/apache/hadoop/hdfs/server/namenode/snapshot/TestSnapshotFileLength.java
@@ -128,6 +128,7 @@ public void testSnapshotfileLength() throws Exception {
         hdfs.getFileChecksum(file1snap1), is(snapChksum1));
     try {
       AppendTestUtil.write(out, 0, toAppend);
+      out.hflush();
       // Test reading from snapshot of file that is open for append
       byte[] dataFromSnapshot = DFSTestUtil.readFileBuffer(hdfs, file1snap1);
       assertThat("Wrong data size in snapshot.",