YugabyteDB (2.13.1.0-b60, 21121d69985fbf76aa6958d8f04a9bfa936293b5)

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// under the License.

//

// The following only applies to changes made to this file as part of YugaByte development.

//

// Portions Copyright (c) YugaByte, Inc.

//

// Licensed under the Apache License, Version 2.0 (the "License"); you may not use this file except

// in compliance with the License.  You may obtain a copy of the License at

//

// http://www.apache.org/licenses/LICENSE-2.0

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// Unless required by applicable law or agreed to in writing, software distributed under the License

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// or implied.  See the License for the specific language governing permissions and limitations

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#ifndef YB_FS_FS_MANAGER_H

#define YB_FS_FS_MANAGER_H

#include <iosfwd>

#include <memory>

#include <set>

#include <string>

#include <vector>

#include <gflags/gflags_declare.h>

#include <gtest/gtest_prod.h>

#include "yb/gutil/ref_counted.h"

#include "yb/util/env.h"

#include "yb/util/metrics.h"

#include "yb/util/path_util.h"

#include "yb/util/strongly_typed_bool.h"

DECLARE_bool(enable_data_block_fsync);

namespace google {

namespace protobuf {

class Message;

} // namespace protobuf

} // namespace google

namespace yb {

class MemTracker;

class MetricEntity;

namespace itest {

class ExternalMiniClusterFsInspector;

}

class InstanceMetadataPB;

YB_STRONGLY_TYPED_BOOL(ShouldDeleteLogs);

struct FsManagerOpts {

  FsManagerOpts();

  ~FsManagerOpts();

  FsManagerOpts(const FsManagerOpts&);

  FsManagerOpts& operator=(const FsManagerOpts&);

  // The entity under which all metrics should be grouped. If NULL, metrics

  // will not be produced.

  //

  // Defaults to NULL.

  scoped_refptr<MetricEntity> metric_entity;

  // The memory tracker under which all new memory trackers will be parented.

  // If NULL, new memory trackers will be parented to the root tracker.

  std::shared_ptr<MemTracker> parent_mem_tracker;

  // The paths where WALs will be stored. Cannot be empty.

  std::vector<std::string> wal_paths;

  // The paths where data blocks will be stored. Cannot be empty.

  std::vector<std::string> data_paths;

  // Whether or not read-write operations should be allowed. Defaults to false.

  bool read_only;

  // This field is to be used as a path component for all the fs roots. For now, we expect it to be

  // either master or tserver.

  std::string server_type;

};

// FsManager provides helpers to read data and metadata files,

// and it's responsible for abstracting the file-system layout.

//

// The user should not be aware of where files are placed,

// but instead should interact with the storage in terms of "open the file xyz"

// or "write a new schema metadata file for table kwz".

//

// The current top-level dir layout is <yb.root.dir>/yb-data/<server>/. Subdirs under it are:

//     logs/

//     instance

//     wals/<table>/<tablet>

//     tablet-meta/<tablet>

//     data/rocksdb/<table>/<tablet>/

//     consensus-meta/<tablet>

class FsManager {

 public:

  static const char *kWalDirName;

  static const char *kWalFileNamePrefix;

  static const char *kWalsRecoveryDirSuffix;

  static const char *kRocksDBDirName;

  static const char *kDataDirName;

  // Only for unit tests.

  FsManager(Env* env, const std::string& root_path, const std::string& server_type);

  FsManager(Env* env, const FsManagerOpts& opts);

  ~FsManager();

  // Initialize and load the basic filesystem metadata.

  // If the file system has not been initialized, returns NotFound.

  // In that case, CreateInitialFileSystemLayout may be used to initialize

  // the on-disk structures.

  CHECKED_STATUS CheckAndOpenFileSystemRoots();

  //

  // Returns an error if the file system is already initialized.

  CHECKED_STATUS CreateInitialFileSystemLayout(bool delete_fs_if_lock_found = false);

  // Deletes the yb-data directory contents for data/wal. "logs" subdirectory deletion is skipped

  // when 'also_delete_logs' is set to false.

  // Needed for a master shell process to be stoppable and restartable correctly in shell mode.

  CHECKED_STATUS DeleteFileSystemLayout(

      ShouldDeleteLogs also_delete_logs = ShouldDeleteLogs::kFalse);

  // Check if a lock file is present.

  bool HasAnyLockFiles();

  // Delete the lock files. Used once the caller deems fs creation was succcessful.

  CHECKED_STATUS DeleteLockFiles();

  void DumpFileSystemTree(std::ostream& out);

  // Return the UUID persisted in the local filesystem. If Open()

  // has not been called, this will crash.

  const std::string& uuid() const;

  // ==========================================================================

  //  on-disk path

  // ==========================================================================

  std::set<std::string> GetFsRootDirs() const;

  std::vector<std::string> GetDataRootDirs() const;

  std::vector<std::string> GetWalRootDirs() const;

  // Used for tests only. If GetWalRootDirs returns an empty vector, we will crash the process.

  std::string GetFirstTabletWalDirOrDie(const std::string& table_id,

                                        const std::string& tablet_id) const;

  static std::string GetTabletWalRecoveryDir(const std::string& tablet_wal_path);

  static std::string GetWalSegmentFileName(uint64_t sequence_number);

  static bool IsWalSegmentFileName(const std::string& file_name);

  static std::string GetWalSegmentFilePath(

      const std::string& wal_path, uint64_t sequence_number) {

    return JoinPathSegments(wal_path, GetWalSegmentFileName(sequence_number));

  }

  // Return the directory where Raft group superblocks should be stored.

  std::string GetRaftGroupMetadataDir() const;

  static std::string GetRaftGroupMetadataDir(const std::string& data_dir);

  // Return the path for a specific Raft group's superblock.

  std::string GetRaftGroupMetadataPath(const std::string& tablet_id) const;

  // List the tablet IDs in the metadata directory.

  CHECKED_STATUS ListTabletIds(std::vector<std::string>* tablet_ids);

  // Return the path where InstanceMetadataPB is stored.

  std::string GetInstanceMetadataPath(const std::string& root) const;

  // Return the path where the fs lock file is stored.

  std::string GetFsLockFilePath(const std::string& root) const;

  // Return the directory where the consensus metadata is stored.

  std::string GetConsensusMetadataDir() const;

  static std::string GetConsensusMetadataDir(const std::string& data_dir);

  // Return the path where ConsensusMetadataPB is stored.

  std::string GetConsensusMetadataPath(const std::string& tablet_id) const {

    return JoinPathSegments(GetConsensusMetadataDir(), tablet_id);

  }

  Env *env() { return env_; }

  bool read_only() const {

    return read_only_;

  }

  // ==========================================================================

  //  file-system helpers

  // ==========================================================================

  bool Exists(const std::string& path) const {

    return env_->FileExists(path);

  }

  CHECKED_STATUS ListDir(const std::string& path, std::vector<std::string> *objects) const;

  Result<std::vector<std::string>> ListDir(const std::string& path) const;

  CHECKED_STATUS CreateDirIfMissing(const std::string& path, bool* created = NULL);

  CHECKED_STATUS CreateDirIfMissingAndSync(const std::string& path, bool* created = NULL);

 private:

  FRIEND_TEST(FsManagerTestBase, TestDuplicatePaths);

  // Initializes, sanitizes, and canonicalizes the filesystem roots.

  CHECKED_STATUS Init();

  // Creates filesystem roots, writing new on-disk instances using 'metadata'.

  CHECKED_STATUS CreateFileSystemRoots(bool create_metadata_dir,

                                       const InstanceMetadataPB& metadata,

                                       bool create_lock = false);

  std::set<std::string> GetAncillaryDirs(bool add_metadata_dirs) const;

  // Create a new InstanceMetadataPB.

  void CreateInstanceMetadata(InstanceMetadataPB* metadata);

  // Save a InstanceMetadataPB to the filesystem.

  // Does not mutate the current state of the fsmanager.

  CHECKED_STATUS WriteInstanceMetadata(

      const InstanceMetadataPB& metadata,

      const std::string& path);

  // Checks if 'path' is an empty directory.

  //

  // Returns an error if it's not a directory. Otherwise, sets 'is_empty'

  // accordingly.

  CHECKED_STATUS IsDirectoryEmpty(const std::string& path, bool* is_empty);

  // Checks write to temporary file on root.

  CHECKED_STATUS CheckWrite(const std::string& path);

  void CreateAndSetFaultDriveMetric(const std::string& path);

  // ==========================================================================

  //  file-system helpers

  // ==========================================================================

  void DumpFileSystemTree(std::ostream& out,

                          const std::string& prefix,

                          const std::string& path,

                          const std::vector<std::string>& objects);

  Env *env_;

  // If false, operations that mutate on-disk state are prohibited.

  const bool read_only_;

  // These roots are the constructor input verbatim. None of them are used

  // as-is; they are first canonicalized during Init().

  const std::vector<std::string> wal_fs_roots_;

  const std::vector<std::string> data_fs_roots_;

  const std::string server_type_;

  scoped_refptr<MetricEntity> metric_entity_;

  std::shared_ptr<MemTracker> parent_mem_tracker_;

  // Canonicalized forms of 'wal_fs_roots_ and 'data_fs_roots_'. Constructed

  // during Init().

  //

  // - The first data root is used as the metadata root.

  // - Common roots in the collections have been deduplicated.

  std::set<std::string> canonicalized_wal_fs_roots_;

  std::string canonicalized_metadata_fs_root_;

  std::set<std::string> canonicalized_data_fs_roots_;

  std::set<std::string> canonicalized_all_fs_roots_;

  std::map<std::string, scoped_refptr<Counter>> counters_;

  std::unique_ptr<InstanceMetadataPB> metadata_;

  bool initted_;

  DISALLOW_COPY_AND_ASSIGN(FsManager);

};

} // namespace yb

#endif  // YB_FS_FS_MANAGER_H