rocksdb/db/db_filesnapshot.cc
Igor Canadi b088c83e6e Don't delete files when column family is dropped
Summary:
To understand the bug read t5943287 and check out the new test in column_family_test (ReadDroppedColumnFamily), iter 0.

RocksDB contract allowes you to read a drop column family as long as there is a live reference. However, since our iteration ignores dropped column families, AddLiveFiles() didn't mark files of a dropped column families as live. So we deleted them.

In this patch I no longer ignore dropped column families in the iteration. I think this behavior was confusing and it also led to this bug. Now if an iterator client wants to ignore dropped column families, he needs to do it explicitly.

Test Plan: Added a new unit test that is failing on master. Unit test succeeds now.

Reviewers: sdong, rven, yhchiang

Reviewed By: yhchiang

Subscribers: dhruba, leveldb

Differential Revision: https://reviews.facebook.net/D32535
2015-03-19 17:04:29 -07:00

152 lines
4.2 KiB
C++

// Copyright (c) 2013, Facebook, Inc. All rights reserved.
// This source code is licensed under the BSD-style license found in the
// LICENSE file in the root directory of this source tree. An additional grant
// of patent rights can be found in the PATENTS file in the same directory.
//
// Copyright (c) 2012 Facebook.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.
#ifndef ROCKSDB_LITE
#ifndef __STDC_FORMAT_MACROS
#define __STDC_FORMAT_MACROS
#endif
#include <inttypes.h>
#include <algorithm>
#include <string>
#include <stdint.h>
#include "db/db_impl.h"
#include "db/filename.h"
#include "db/job_context.h"
#include "db/version_set.h"
#include "rocksdb/db.h"
#include "rocksdb/env.h"
#include "port/port.h"
#include "util/mutexlock.h"
#include "util/sync_point.h"
#include "util/file_util.h"
namespace rocksdb {
Status DBImpl::DisableFileDeletions() {
InstrumentedMutexLock l(&mutex_);
++disable_delete_obsolete_files_;
if (disable_delete_obsolete_files_ == 1) {
Log(InfoLogLevel::INFO_LEVEL, db_options_.info_log,
"File Deletions Disabled");
} else {
Log(InfoLogLevel::WARN_LEVEL, db_options_.info_log,
"File Deletions Disabled, but already disabled. Counter: %d",
disable_delete_obsolete_files_);
}
return Status::OK();
}
Status DBImpl::EnableFileDeletions(bool force) {
// Job id == 0 means that this is not our background process, but rather
// user thread
JobContext job_context(0);
bool should_purge_files = false;
{
InstrumentedMutexLock l(&mutex_);
if (force) {
// if force, we need to enable file deletions right away
disable_delete_obsolete_files_ = 0;
} else if (disable_delete_obsolete_files_ > 0) {
--disable_delete_obsolete_files_;
}
if (disable_delete_obsolete_files_ == 0) {
Log(InfoLogLevel::INFO_LEVEL, db_options_.info_log,
"File Deletions Enabled");
should_purge_files = true;
FindObsoleteFiles(&job_context, true);
} else {
Log(InfoLogLevel::WARN_LEVEL, db_options_.info_log,
"File Deletions Enable, but not really enabled. Counter: %d",
disable_delete_obsolete_files_);
}
}
if (should_purge_files) {
PurgeObsoleteFiles(job_context);
}
job_context.Clean();
LogFlush(db_options_.info_log);
return Status::OK();
}
int DBImpl::IsFileDeletionsEnabled() const {
return disable_delete_obsolete_files_;
}
Status DBImpl::GetLiveFiles(std::vector<std::string>& ret,
uint64_t* manifest_file_size,
bool flush_memtable) {
*manifest_file_size = 0;
mutex_.Lock();
if (flush_memtable) {
// flush all dirty data to disk.
Status status;
for (auto cfd : *versions_->GetColumnFamilySet()) {
if (cfd->IsDropped()) {
continue;
}
cfd->Ref();
mutex_.Unlock();
status = FlushMemTable(cfd, FlushOptions());
mutex_.Lock();
cfd->Unref();
if (!status.ok()) {
break;
}
}
versions_->GetColumnFamilySet()->FreeDeadColumnFamilies();
if (!status.ok()) {
mutex_.Unlock();
Log(InfoLogLevel::ERROR_LEVEL, db_options_.info_log,
"Cannot Flush data %s\n", status.ToString().c_str());
return status;
}
}
// Make a set of all of the live *.sst files
std::vector<FileDescriptor> live;
for (auto cfd : *versions_->GetColumnFamilySet()) {
if (cfd->IsDropped()) {
continue;
}
cfd->current()->AddLiveFiles(&live);
}
ret.clear();
ret.reserve(live.size() + 2); //*.sst + CURRENT + MANIFEST
// create names of the live files. The names are not absolute
// paths, instead they are relative to dbname_;
for (auto live_file : live) {
ret.push_back(MakeTableFileName("", live_file.GetNumber()));
}
ret.push_back(CurrentFileName(""));
ret.push_back(DescriptorFileName("", versions_->manifest_file_number()));
// find length of manifest file while holding the mutex lock
*manifest_file_size = versions_->manifest_file_size();
mutex_.Unlock();
return Status::OK();
}
Status DBImpl::GetSortedWalFiles(VectorLogPtr& files) {
return wal_manager_.GetSortedWalFiles(files);
}
}
#endif // ROCKSDB_LITE