From d60ae5b1c7e70efd32c7b8ccd939fa0ecc94e9a2 Mon Sep 17 00:00:00 2001
From: Jay Zhuang <zjay@fb.com>
Date: Mon, 14 Jun 2021 08:10:37 -0700
Subject: [PATCH] Fix flaky ManualCompactionMax test (#8396)

Summary:
Recalculate the total size after generate new sst files.
New generated files might have different size as the previous time which
could cause the test failed.

Pull Request resolved: https://github.com/facebook/rocksdb/pull/8396

Test Plan:
```
gtest-parallel ./db_compaction_test
--gtest_filter=DBCompactionTest.ManualCompactionMax -r 1000 -w 100
```

Reviewed By: akankshamahajan15

Differential Revision: D29083299

Pulled By: jay-zhuang

fbshipit-source-id: 49d4bd619cefc0f9a1f452f8759ff4c2ba1b6fdb
---
 db/db_compaction_test.cc | 8 +++++---
 1 file changed, 5 insertions(+), 3 deletions(-)

diff --git a/db/db_compaction_test.cc b/db/db_compaction_test.cc
index 37bea4ab1f..98836d4275 100644
--- a/db/db_compaction_test.cc
+++ b/db/db_compaction_test.cc
@@ -5208,11 +5208,12 @@ TEST_F(DBCompactionTest, ManualCompactionMax) {
   ASSERT_TRUE(num_compactions.load() == 1);
 
   // split the compaction to 5
-  uint64_t total = (l1_avg_size * 10) + (l2_avg_size * 100);
   int num_split = 5;
-  opts.max_compaction_bytes = total / num_split;
   DestroyAndReopen(opts);
   generate_sst_func();
+  uint64_t total_size = (l1_avg_size * 10) + (l2_avg_size * 100);
+  opts.max_compaction_bytes = total_size / num_split;
+  Reopen(opts);
   num_compactions.store(0);
   ASSERT_OK(db_->CompactRange(cro, nullptr, nullptr));
   ASSERT_TRUE(num_compactions.load() == num_split);
@@ -5230,8 +5231,9 @@ TEST_F(DBCompactionTest, ManualCompactionMax) {
   opts.max_compaction_bytes = 0;
   DestroyAndReopen(opts);
   generate_sst_func();
+  total_size = (l1_avg_size * 10) + (l2_avg_size * 100);
   Status s = db_->SetOptions(
-      {{"max_compaction_bytes", std::to_string(total / num_split)}});
+      {{"max_compaction_bytes", std::to_string(total_size / num_split)}});
   ASSERT_OK(s);
 
   num_compactions.store(0);