rocksdb/util/delete_scheduler_test.cc
Islam AbdelRahman 3e5ea29a83 Fix Flaky DeleteSchedulerTest::ImmediateDeleteOn25PercDBSize
Summary:
In this test we are deleting 100 files, and we are expecting DeleteScheduler to delete 26 files in the background and 74 files immediately in the foreground

The main purpose of the test is to make sure that we delete files in foreground thread, which is verified in line 546

But sometimes we may end up with 26 files or 25 files in the trash directory because the background thread may be slow and not be able to delete the first file fast enough, so sometimes this test fail.

Remove
```
ASSERT_EQ(CountFilesInDir(trash_dir_), 25);
```
Since it does not have any benefit any way
Closes https://github.com/facebook/rocksdb/pull/2618

Differential Revision: D5458674

Pulled By: IslamAbdelRahman

fbshipit-source-id: 5556a9edfa049db71dce80b8e6ae0fdd25e1e74e
2017-07-20 11:29:01 -07:00

564 lines
20 KiB
C++

// Copyright (c) 2011-present, Facebook, Inc. All rights reserved.
// This source code is licensed under both the GPLv2 (found in the
// COPYING file in the root directory) and Apache 2.0 License
// (found in the LICENSE.Apache file in the root directory).
#ifndef __STDC_FORMAT_MACROS
#define __STDC_FORMAT_MACROS
#endif
#include <inttypes.h>
#include <atomic>
#include <thread>
#include <vector>
#include "rocksdb/env.h"
#include "rocksdb/options.h"
#include "util/delete_scheduler.h"
#include "util/sst_file_manager_impl.h"
#include "util/string_util.h"
#include "util/sync_point.h"
#include "util/testharness.h"
#include "util/testutil.h"
#ifndef ROCKSDB_LITE
namespace rocksdb {
class DeleteSchedulerTest : public testing::Test {
public:
DeleteSchedulerTest() : env_(Env::Default()) {
dummy_files_dir_ = test::TmpDir(env_) + "/delete_scheduler_dummy_data_dir";
DestroyAndCreateDir(dummy_files_dir_);
trash_dir_ = test::TmpDir(env_) + "/delete_scheduler_trash";
DestroyAndCreateDir(trash_dir_);
}
~DeleteSchedulerTest() {
rocksdb::SyncPoint::GetInstance()->DisableProcessing();
rocksdb::SyncPoint::GetInstance()->LoadDependency({});
rocksdb::SyncPoint::GetInstance()->ClearAllCallBacks();
test::DestroyDir(env_, dummy_files_dir_);
}
void DestroyAndCreateDir(const std::string& dir) {
ASSERT_OK(test::DestroyDir(env_, dir));
EXPECT_OK(env_->CreateDir(dir));
}
int CountFilesInDir(const std::string& dir) {
std::vector<std::string> files_in_dir;
EXPECT_OK(env_->GetChildren(dir, &files_in_dir));
// Ignore "." and ".."
return static_cast<int>(files_in_dir.size()) - 2;
}
std::string NewDummyFile(const std::string& file_name, uint64_t size = 1024) {
std::string file_path = dummy_files_dir_ + "/" + file_name;
std::unique_ptr<WritableFile> f;
env_->NewWritableFile(file_path, &f, EnvOptions());
std::string data(size, 'A');
EXPECT_OK(f->Append(data));
EXPECT_OK(f->Close());
sst_file_mgr_->OnAddFile(file_path);
return file_path;
}
void NewDeleteScheduler() {
ASSERT_OK(env_->CreateDirIfMissing(trash_dir_));
sst_file_mgr_.reset(
new SstFileManagerImpl(env_, nullptr, trash_dir_, rate_bytes_per_sec_));
delete_scheduler_ = sst_file_mgr_->delete_scheduler();
// Tests in this file are for DeleteScheduler component and dont create any
// DBs, so we need to use set this value to 100% (instead of default 25%)
delete_scheduler_->TEST_SetMaxTrashDBRatio(1.1);
}
Env* env_;
std::string dummy_files_dir_;
std::string trash_dir_;
int64_t rate_bytes_per_sec_;
DeleteScheduler* delete_scheduler_;
std::unique_ptr<SstFileManagerImpl> sst_file_mgr_;
};
// Test the basic functionality of DeleteScheduler (Rate Limiting).
// 1- Create 100 dummy files
// 2- Delete the 100 dummy files using DeleteScheduler
// --- Hold DeleteScheduler::BackgroundEmptyTrash ---
// 3- Wait for DeleteScheduler to delete all files in trash
// 4- Verify that BackgroundEmptyTrash used to correct penlties for the files
// 5- Make sure that all created files were completely deleted
TEST_F(DeleteSchedulerTest, BasicRateLimiting) {
rocksdb::SyncPoint::GetInstance()->LoadDependency({
{"DeleteSchedulerTest::BasicRateLimiting:1",
"DeleteScheduler::BackgroundEmptyTrash"},
});
std::vector<uint64_t> penalties;
rocksdb::SyncPoint::GetInstance()->SetCallBack(
"DeleteScheduler::BackgroundEmptyTrash:Wait",
[&](void* arg) { penalties.push_back(*(static_cast<uint64_t*>(arg))); });
int num_files = 100; // 100 files
uint64_t file_size = 1024; // every file is 1 kb
std::vector<uint64_t> delete_kbs_per_sec = {512, 200, 100, 50, 25};
for (size_t t = 0; t < delete_kbs_per_sec.size(); t++) {
penalties.clear();
rocksdb::SyncPoint::GetInstance()->ClearTrace();
rocksdb::SyncPoint::GetInstance()->EnableProcessing();
DestroyAndCreateDir(dummy_files_dir_);
rate_bytes_per_sec_ = delete_kbs_per_sec[t] * 1024;
NewDeleteScheduler();
// Create 100 dummy files, every file is 1 Kb
std::vector<std::string> generated_files;
for (int i = 0; i < num_files; i++) {
std::string file_name = "file" + ToString(i) + ".data";
generated_files.push_back(NewDummyFile(file_name, file_size));
}
// Delete dummy files and measure time spent to empty trash
for (int i = 0; i < num_files; i++) {
ASSERT_OK(delete_scheduler_->DeleteFile(generated_files[i]));
}
ASSERT_EQ(CountFilesInDir(dummy_files_dir_), 0);
uint64_t delete_start_time = env_->NowMicros();
TEST_SYNC_POINT("DeleteSchedulerTest::BasicRateLimiting:1");
delete_scheduler_->WaitForEmptyTrash();
uint64_t time_spent_deleting = env_->NowMicros() - delete_start_time;
auto bg_errors = delete_scheduler_->GetBackgroundErrors();
ASSERT_EQ(bg_errors.size(), 0);
uint64_t total_files_size = 0;
uint64_t expected_penlty = 0;
ASSERT_EQ(penalties.size(), num_files);
for (int i = 0; i < num_files; i++) {
total_files_size += file_size;
expected_penlty = ((total_files_size * 1000000) / rate_bytes_per_sec_);
ASSERT_EQ(expected_penlty, penalties[i]);
}
ASSERT_GT(time_spent_deleting, expected_penlty * 0.9);
ASSERT_EQ(CountFilesInDir(trash_dir_), 0);
rocksdb::SyncPoint::GetInstance()->DisableProcessing();
}
}
// Same as the BasicRateLimiting test but delete files in multiple threads.
// 1- Create 100 dummy files
// 2- Delete the 100 dummy files using DeleteScheduler using 10 threads
// --- Hold DeleteScheduler::BackgroundEmptyTrash ---
// 3- Wait for DeleteScheduler to delete all files in queue
// 4- Verify that BackgroundEmptyTrash used to correct penlties for the files
// 5- Make sure that all created files were completely deleted
TEST_F(DeleteSchedulerTest, RateLimitingMultiThreaded) {
rocksdb::SyncPoint::GetInstance()->LoadDependency({
{"DeleteSchedulerTest::RateLimitingMultiThreaded:1",
"DeleteScheduler::BackgroundEmptyTrash"},
});
std::vector<uint64_t> penalties;
rocksdb::SyncPoint::GetInstance()->SetCallBack(
"DeleteScheduler::BackgroundEmptyTrash:Wait",
[&](void* arg) { penalties.push_back(*(static_cast<uint64_t*>(arg))); });
int thread_cnt = 10;
int num_files = 10; // 10 files per thread
uint64_t file_size = 1024; // every file is 1 kb
std::vector<uint64_t> delete_kbs_per_sec = {512, 200, 100, 50, 25};
for (size_t t = 0; t < delete_kbs_per_sec.size(); t++) {
penalties.clear();
rocksdb::SyncPoint::GetInstance()->ClearTrace();
rocksdb::SyncPoint::GetInstance()->EnableProcessing();
DestroyAndCreateDir(dummy_files_dir_);
rate_bytes_per_sec_ = delete_kbs_per_sec[t] * 1024;
NewDeleteScheduler();
// Create 100 dummy files, every file is 1 Kb
std::vector<std::string> generated_files;
for (int i = 0; i < num_files * thread_cnt; i++) {
std::string file_name = "file" + ToString(i) + ".data";
generated_files.push_back(NewDummyFile(file_name, file_size));
}
// Delete dummy files using 10 threads and measure time spent to empty trash
std::atomic<int> thread_num(0);
std::vector<port::Thread> threads;
std::function<void()> delete_thread = [&]() {
int idx = thread_num.fetch_add(1);
int range_start = idx * num_files;
int range_end = range_start + num_files;
for (int j = range_start; j < range_end; j++) {
ASSERT_OK(delete_scheduler_->DeleteFile(generated_files[j]));
}
};
for (int i = 0; i < thread_cnt; i++) {
threads.emplace_back(delete_thread);
}
for (size_t i = 0; i < threads.size(); i++) {
threads[i].join();
}
uint64_t delete_start_time = env_->NowMicros();
TEST_SYNC_POINT("DeleteSchedulerTest::RateLimitingMultiThreaded:1");
delete_scheduler_->WaitForEmptyTrash();
uint64_t time_spent_deleting = env_->NowMicros() - delete_start_time;
auto bg_errors = delete_scheduler_->GetBackgroundErrors();
ASSERT_EQ(bg_errors.size(), 0);
uint64_t total_files_size = 0;
uint64_t expected_penlty = 0;
ASSERT_EQ(penalties.size(), num_files * thread_cnt);
for (int i = 0; i < num_files * thread_cnt; i++) {
total_files_size += file_size;
expected_penlty = ((total_files_size * 1000000) / rate_bytes_per_sec_);
ASSERT_EQ(expected_penlty, penalties[i]);
}
ASSERT_GT(time_spent_deleting, expected_penlty * 0.9);
ASSERT_EQ(CountFilesInDir(dummy_files_dir_), 0);
ASSERT_EQ(CountFilesInDir(trash_dir_), 0);
rocksdb::SyncPoint::GetInstance()->DisableProcessing();
}
}
// Disable rate limiting by setting rate_bytes_per_sec_ to 0 and make sure
// that when DeleteScheduler delete a file it delete it immediately and dont
// move it to trash
TEST_F(DeleteSchedulerTest, DisableRateLimiting) {
int bg_delete_file = 0;
rocksdb::SyncPoint::GetInstance()->SetCallBack(
"DeleteScheduler::DeleteTrashFile:DeleteFile",
[&](void* arg) { bg_delete_file++; });
rocksdb::SyncPoint::GetInstance()->EnableProcessing();
rate_bytes_per_sec_ = 0;
NewDeleteScheduler();
for (int i = 0; i < 10; i++) {
// Every file we delete will be deleted immediately
std::string dummy_file = NewDummyFile("dummy.data");
ASSERT_OK(delete_scheduler_->DeleteFile(dummy_file));
ASSERT_TRUE(env_->FileExists(dummy_file).IsNotFound());
ASSERT_EQ(CountFilesInDir(dummy_files_dir_), 0);
ASSERT_EQ(CountFilesInDir(trash_dir_), 0);
}
ASSERT_EQ(bg_delete_file, 0);
rocksdb::SyncPoint::GetInstance()->DisableProcessing();
}
// Testing that moving files to trash with the same name is not a problem
// 1- Create 10 files with the same name "conflict.data"
// 2- Delete the 10 files using DeleteScheduler
// 3- Make sure that trash directory contain 10 files ("conflict.data" x 10)
// --- Hold DeleteScheduler::BackgroundEmptyTrash ---
// 4- Make sure that files are deleted from trash
TEST_F(DeleteSchedulerTest, ConflictNames) {
rocksdb::SyncPoint::GetInstance()->LoadDependency({
{"DeleteSchedulerTest::ConflictNames:1",
"DeleteScheduler::BackgroundEmptyTrash"},
});
rocksdb::SyncPoint::GetInstance()->EnableProcessing();
rate_bytes_per_sec_ = 1024 * 1024; // 1 Mb/sec
NewDeleteScheduler();
// Create "conflict.data" and move it to trash 10 times
for (int i = 0; i < 10; i++) {
std::string dummy_file = NewDummyFile("conflict.data");
ASSERT_OK(delete_scheduler_->DeleteFile(dummy_file));
}
ASSERT_EQ(CountFilesInDir(dummy_files_dir_), 0);
// 10 files ("conflict.data" x 10) in trash
ASSERT_EQ(CountFilesInDir(trash_dir_), 10);
// Hold BackgroundEmptyTrash
TEST_SYNC_POINT("DeleteSchedulerTest::ConflictNames:1");
delete_scheduler_->WaitForEmptyTrash();
ASSERT_EQ(CountFilesInDir(trash_dir_), 0);
auto bg_errors = delete_scheduler_->GetBackgroundErrors();
ASSERT_EQ(bg_errors.size(), 0);
rocksdb::SyncPoint::GetInstance()->DisableProcessing();
}
// 1- Create 10 dummy files
// 2- Delete the 10 files using DeleteScheduler (move them to trsah)
// 3- Delete the 10 files directly (using env_->DeleteFile)
// --- Hold DeleteScheduler::BackgroundEmptyTrash ---
// 4- Make sure that DeleteScheduler failed to delete the 10 files and
// reported 10 background errors
TEST_F(DeleteSchedulerTest, BackgroundError) {
rocksdb::SyncPoint::GetInstance()->LoadDependency({
{"DeleteSchedulerTest::BackgroundError:1",
"DeleteScheduler::BackgroundEmptyTrash"},
});
rocksdb::SyncPoint::GetInstance()->EnableProcessing();
rate_bytes_per_sec_ = 1024 * 1024; // 1 Mb/sec
NewDeleteScheduler();
// Generate 10 dummy files and move them to trash
for (int i = 0; i < 10; i++) {
std::string file_name = "data_" + ToString(i) + ".data";
ASSERT_OK(delete_scheduler_->DeleteFile(NewDummyFile(file_name)));
}
ASSERT_EQ(CountFilesInDir(dummy_files_dir_), 0);
ASSERT_EQ(CountFilesInDir(trash_dir_), 10);
// Delete 10 files from trash, this will cause background errors in
// BackgroundEmptyTrash since we already deleted the files it was
// goind to delete
for (int i = 0; i < 10; i++) {
std::string file_name = "data_" + ToString(i) + ".data";
ASSERT_OK(env_->DeleteFile(trash_dir_ + "/" + file_name));
}
// Hold BackgroundEmptyTrash
TEST_SYNC_POINT("DeleteSchedulerTest::BackgroundError:1");
delete_scheduler_->WaitForEmptyTrash();
auto bg_errors = delete_scheduler_->GetBackgroundErrors();
ASSERT_EQ(bg_errors.size(), 10);
rocksdb::SyncPoint::GetInstance()->DisableProcessing();
}
// 1- Create 10 dummy files
// 2- Delete 10 dummy files using DeleteScheduler
// 3- Wait for DeleteScheduler to delete all files in queue
// 4- Make sure all files in trash directory were deleted
// 5- Repeat previous steps 5 times
TEST_F(DeleteSchedulerTest, StartBGEmptyTrashMultipleTimes) {
int bg_delete_file = 0;
rocksdb::SyncPoint::GetInstance()->SetCallBack(
"DeleteScheduler::DeleteTrashFile:DeleteFile",
[&](void* arg) { bg_delete_file++; });
rocksdb::SyncPoint::GetInstance()->EnableProcessing();
rate_bytes_per_sec_ = 1024 * 1024; // 1 MB / sec
NewDeleteScheduler();
// Move files to trash, wait for empty trash, start again
for (int run = 1; run <= 5; run++) {
// Generate 10 dummy files and move them to trash
for (int i = 0; i < 10; i++) {
std::string file_name = "data_" + ToString(i) + ".data";
ASSERT_OK(delete_scheduler_->DeleteFile(NewDummyFile(file_name)));
}
ASSERT_EQ(CountFilesInDir(dummy_files_dir_), 0);
delete_scheduler_->WaitForEmptyTrash();
ASSERT_EQ(bg_delete_file, 10 * run);
ASSERT_EQ(CountFilesInDir(trash_dir_), 0);
auto bg_errors = delete_scheduler_->GetBackgroundErrors();
ASSERT_EQ(bg_errors.size(), 0);
}
ASSERT_EQ(bg_delete_file, 50);
rocksdb::SyncPoint::GetInstance()->EnableProcessing();
}
// 1- Create a DeleteScheduler with very slow rate limit (1 Byte / sec)
// 2- Delete 100 files using DeleteScheduler
// 3- Delete the DeleteScheduler (call the destructor while queue is not empty)
// 4- Make sure that not all files were deleted from trash and that
// DeleteScheduler background thread did not delete all files
TEST_F(DeleteSchedulerTest, DestructorWithNonEmptyQueue) {
int bg_delete_file = 0;
rocksdb::SyncPoint::GetInstance()->SetCallBack(
"DeleteScheduler::DeleteTrashFile:DeleteFile",
[&](void* arg) { bg_delete_file++; });
rocksdb::SyncPoint::GetInstance()->EnableProcessing();
rate_bytes_per_sec_ = 1; // 1 Byte / sec
NewDeleteScheduler();
for (int i = 0; i < 100; i++) {
std::string file_name = "data_" + ToString(i) + ".data";
ASSERT_OK(delete_scheduler_->DeleteFile(NewDummyFile(file_name)));
}
// Deleting 100 files will need >28 hours to delete
// we will delete the DeleteScheduler while delete queue is not empty
sst_file_mgr_.reset();
ASSERT_LT(bg_delete_file, 100);
ASSERT_GT(CountFilesInDir(trash_dir_), 0);
rocksdb::SyncPoint::GetInstance()->DisableProcessing();
}
// 1- Delete the trash directory
// 2- Delete 10 files using DeleteScheduler
// 3- Make sure that the 10 files were deleted immediately since DeleteScheduler
// failed to move them to trash directory
TEST_F(DeleteSchedulerTest, MoveToTrashError) {
int bg_delete_file = 0;
rocksdb::SyncPoint::GetInstance()->SetCallBack(
"DeleteScheduler::DeleteTrashFile:DeleteFile",
[&](void* arg) { bg_delete_file++; });
rocksdb::SyncPoint::GetInstance()->EnableProcessing();
rate_bytes_per_sec_ = 1024; // 1 Kb / sec
NewDeleteScheduler();
// We will delete the trash directory, that mean that DeleteScheduler wont
// be able to move files to trash and will delete files them immediately.
ASSERT_OK(test::DestroyDir(env_, trash_dir_));
for (int i = 0; i < 10; i++) {
std::string file_name = "data_" + ToString(i) + ".data";
ASSERT_OK(delete_scheduler_->DeleteFile(NewDummyFile(file_name)));
}
ASSERT_EQ(CountFilesInDir(dummy_files_dir_), 0);
ASSERT_EQ(bg_delete_file, 0);
rocksdb::SyncPoint::GetInstance()->DisableProcessing();
}
TEST_F(DeleteSchedulerTest, DISABLED_DynamicRateLimiting1) {
std::vector<uint64_t> penalties;
int bg_delete_file = 0;
int fg_delete_file = 0;
rocksdb::SyncPoint::GetInstance()->SetCallBack(
"DeleteScheduler::DeleteTrashFile:DeleteFile",
[&](void* arg) { bg_delete_file++; });
rocksdb::SyncPoint::GetInstance()->SetCallBack(
"DeleteScheduler::DeleteFile",
[&](void* arg) { fg_delete_file++; });
rocksdb::SyncPoint::GetInstance()->SetCallBack(
"DeleteScheduler::BackgroundEmptyTrash:Wait",
[&](void* arg) { penalties.push_back(*(static_cast<int*>(arg))); });
rocksdb::SyncPoint::GetInstance()->LoadDependency({
{"DeleteSchedulerTest::DynamicRateLimiting1:1",
"DeleteScheduler::BackgroundEmptyTrash"},
});
rocksdb::SyncPoint::GetInstance()->EnableProcessing();
rate_bytes_per_sec_ = 0; // Disable rate limiting initially
NewDeleteScheduler();
int num_files = 10; // 10 files
uint64_t file_size = 1024; // every file is 1 kb
std::vector<int64_t> delete_kbs_per_sec = {512, 200, 0, 100, 50, -2, 25};
for (size_t t = 0; t < delete_kbs_per_sec.size(); t++) {
penalties.clear();
bg_delete_file = 0;
fg_delete_file = 0;
rocksdb::SyncPoint::GetInstance()->ClearTrace();
rocksdb::SyncPoint::GetInstance()->EnableProcessing();
DestroyAndCreateDir(dummy_files_dir_);
rate_bytes_per_sec_ = delete_kbs_per_sec[t] * 1024;
delete_scheduler_->SetRateBytesPerSecond(rate_bytes_per_sec_);
// Create 100 dummy files, every file is 1 Kb
std::vector<std::string> generated_files;
for (int i = 0; i < num_files; i++) {
std::string file_name = "file" + ToString(i) + ".data";
generated_files.push_back(NewDummyFile(file_name, file_size));
}
// Delete dummy files and measure time spent to empty trash
for (int i = 0; i < num_files; i++) {
ASSERT_OK(delete_scheduler_->DeleteFile(generated_files[i]));
}
ASSERT_EQ(CountFilesInDir(dummy_files_dir_), 0);
if (rate_bytes_per_sec_ > 0) {
uint64_t delete_start_time = env_->NowMicros();
TEST_SYNC_POINT("DeleteSchedulerTest::DynamicRateLimiting1:1");
delete_scheduler_->WaitForEmptyTrash();
uint64_t time_spent_deleting = env_->NowMicros() - delete_start_time;
auto bg_errors = delete_scheduler_->GetBackgroundErrors();
ASSERT_EQ(bg_errors.size(), 0);
uint64_t total_files_size = 0;
uint64_t expected_penlty = 0;
ASSERT_EQ(penalties.size(), num_files);
for (int i = 0; i < num_files; i++) {
total_files_size += file_size;
expected_penlty = ((total_files_size * 1000000) / rate_bytes_per_sec_);
ASSERT_EQ(expected_penlty, penalties[i]);
}
ASSERT_GT(time_spent_deleting, expected_penlty * 0.9);
ASSERT_EQ(bg_delete_file, num_files);
ASSERT_EQ(fg_delete_file, 0);
} else {
ASSERT_EQ(penalties.size(), 0);
ASSERT_EQ(bg_delete_file, 0);
ASSERT_EQ(fg_delete_file, num_files);
}
ASSERT_EQ(CountFilesInDir(trash_dir_), 0);
rocksdb::SyncPoint::GetInstance()->DisableProcessing();
}
}
TEST_F(DeleteSchedulerTest, ImmediateDeleteOn25PercDBSize) {
int bg_delete_file = 0;
int fg_delete_file = 0;
rocksdb::SyncPoint::GetInstance()->SetCallBack(
"DeleteScheduler::DeleteTrashFile:DeleteFile",
[&](void* arg) { bg_delete_file++; });
rocksdb::SyncPoint::GetInstance()->SetCallBack(
"DeleteScheduler::DeleteFile", [&](void* arg) { fg_delete_file++; });
rocksdb::SyncPoint::GetInstance()->EnableProcessing();
int num_files = 100; // 100 files
uint64_t file_size = 1024 * 10; // 100 KB as a file size
rate_bytes_per_sec_ = 1; // 1 byte per sec (very slow trash delete)
NewDeleteScheduler();
delete_scheduler_->TEST_SetMaxTrashDBRatio(0.25);
std::vector<std::string> generated_files;
for (int i = 0; i < num_files; i++) {
std::string file_name = "file" + ToString(i) + ".data";
generated_files.push_back(NewDummyFile(file_name, file_size));
}
for (std::string& file_name : generated_files) {
delete_scheduler_->DeleteFile(file_name);
}
// When we end up with 26 files in trash we will start
// deleting new files immediately
ASSERT_EQ(fg_delete_file, 74);
rocksdb::SyncPoint::GetInstance()->DisableProcessing();
}
} // namespace rocksdb
int main(int argc, char** argv) {
::testing::InitGoogleTest(&argc, argv);
return RUN_ALL_TESTS();
}
#else
int main(int argc, char** argv) {
printf("DeleteScheduler is not supported in ROCKSDB_LITE\n");
return 0;
}
#endif // ROCKSDB_LITE