Fix flaky test BackupableDBTest.FileSizeForIncremental (#8197)

Summary:
Test was flaky because for kUseDbSessionId naming, blob files use
naming scheme kLegacyCrc32cAndFileSize. So expected number of files
because of collision can vary. So disabling blobdb for this test case.

Pull Request resolved: https://github.com/facebook/rocksdb/pull/8197

Reviewed By: pdillinger

Differential Revision: D27836997

Pulled By: akankshamahajan15

fbshipit-source-id: 5eb21a5f4acae3d6b730a9e1b207264fbc18cb80

utilities/backupable/backupable_db_test.cc

@@ -2168,6 +2168,8 @@ TEST_F(BackupableDBTest, TableFileCorruptionBeforeIncremental) {
 // between incremental backups
 TEST_F(BackupableDBTest, FileSizeForIncremental) {
   const auto share_no_checksum = static_cast<ShareFilesNaming>(0);
+  // TODO: enable blob files once Integrated BlobDB supports DB session id.
+  options_.enable_blob_files = false;
 
   for (ShareFilesNaming option : {share_no_checksum, kLegacyCrc32cAndFileSize,
                                   kNamingDefault, kUseDbSessionId}) {
@@ -2192,9 +2194,9 @@ TEST_F(BackupableDBTest, FileSizeForIncremental) {
     ASSERT_OK(backup_engine_->CreateNewBackup(db_.get(), true /*flush*/));
     CloseDBAndBackupEngine();
 
-    // Corrupt backup SST and blob file
+    // Corrupt backup SST file
     ASSERT_OK(file_manager_->GetChildrenFileAttributes(shared_dir, &children));
-    ASSERT_EQ(children.size(), 2U);  // one sst and one blob file
+    ASSERT_EQ(children.size(), 1U);  // one sst
     for (const auto& child : children) {
       if (child.name.size() > 4 && child.size_bytes > 0) {
         ASSERT_OK(
@@ -2251,10 +2253,10 @@ TEST_F(BackupableDBTest, FileSizeForIncremental) {
     OpenDBAndBackupEngine(false, false, share);
     ASSERT_OK(db_->Put(WriteOptions(), "y", Random(42).RandomString(500)));
 
-    // Count backup SSTs and blob files.
+    // Count backup SSTs files.
     children.clear();
     ASSERT_OK(file_manager_->GetChildrenFileAttributes(shared_dir, &children));
-    ASSERT_EQ(children.size(), 4U);  // two sst and two blob files
+    ASSERT_EQ(children.size(), 2U);  // two sst files
 
     // Try create backup 3
     s = backup_engine_->CreateNewBackup(db_.get(), true /*flush*/);
@@ -2267,18 +2269,18 @@ TEST_F(BackupableDBTest, FileSizeForIncremental) {
       // Acceptable to call it corruption if size is not in name and
       // db session id collision is practically impossible.
       EXPECT_TRUE(s.IsCorruption());
-      EXPECT_EQ(children.size(), 4U);  // no SST/Blob file added
+      EXPECT_EQ(children.size(), 2U);  // no SST file added
     } else if (option == share_no_checksum) {
       // Good to call it corruption if both backups cannot be
       // accommodated.
       EXPECT_TRUE(s.IsCorruption());
-      EXPECT_EQ(children.size(), 4U);  // no SST/Blob file added
+      EXPECT_EQ(children.size(), 2U);  // no SST file added
     } else {
       // Since opening a DB seems sufficient for detecting size corruption
       // on the DB side, this should be a good thing, ...
       EXPECT_OK(s);
       // ... as long as we did actually treat it as a distinct SST file.
-      EXPECT_EQ(children.size(), 6U);  // Another SST and blob added
+      EXPECT_EQ(children.size(), 3U);  // Another SST added
     }
     CloseDBAndBackupEngine();
     ASSERT_OK(DestroyDB(dbname_, options_));