buf0dblwr.cc File Reference

Atomic writes handling. More...

#include <sys/types.h>
#include "buf0buf.h"
#include "buf0checksum.h"
#include "log0chkp.h"
#include "os0enc.h"
#include "os0thread-create.h"
#include "page0zip.h"
#include "srv0srv.h"
#include "srv0start.h"
#include "ut0mpmcbq.h"
#include "ut0mutex.h"
#include "ut0test.h"
#include <iomanip>
#include <iostream>
#include <regex>
#include <vector>

Classes
struct	dblwr::File
struct	dblwr::recv::Page
	Page recovered from the doublewrite buffer. More...
struct	dblwr::recv::Page_entry
	A record from reduced doublewrite buffer. More...
class	dblwr::recv::Pages
	Pages recovered from the doublewrite buffer. More...
class	Double_write
	Doublewrite implementation. More...
struct	Double_write::Buf_pages
	For collecting pages to write. More...
class	Segment
	File segment of a double write file. More...
class	Batch_segment
	Segment for batched writes. More...
class	Reduced_double_write
	Reduced doublewrite implementation. More...
class	Reduced_batch_deserializer
	Reduced doublewrite file deserializer. More...

Namespaces
namespace	dblwr
namespace	dblwr::recv

Functions
bool	dblwr::is_odd (uint32_t val)
std::ostream &	dblwr::operator<< (std::ostream &out, const File &obj) noexcept
	Overload the global output operator to work with dblwr::File type. More...
static bool	is_buffer_pool_size_ok () noexcept
static dberr_t	dblwr_file_open (const std::string &dir_name, int id, dblwr::File &file, ulint file_type, ib_file_suffix extension=DWR) noexcept
	Create the file and or open it if it exists. More...
static bool	is_dblwr_page_corrupted (byte *page, fil_space_t *space, page_no_t page_no, dberr_t *err) noexcept
	Check if the dblwr page is corrupted. More...
static bool	dblwr::is_encrypted_page (const byte *page) noexcept
bool	dblwr::has_encrypted_pages () noexcept
	Check if the dblwr files contain encrypted pages. More...

Variables
constexpr ulint	DBLWR_V1_FSEG = 0
	Doublewrite buffer. More...
constexpr ulint	DBLWR_V1_REPEAT = 12
	We repeat DBLWR_VER, DBLWR_V1_BLOCK1, DBLWR_V1_BLOCK2 so that if the trx sys header is half-written to disk, we still may be able to recover the information. More...
constexpr ulint	DBLWR_V1_SPACE_ID_STORED = (24 + FSEG_HEADER_SIZE)
	If this is not yet set to DBLWR_V1_SPACE_ID_STORED_N, we must reset the doublewrite buffer, because starting from 4.1.x the space id of a data page is stored into FIL_PAGE_ARCH_LOG_NO_OR_SPACE_ID. More...
constexpr ulint	DBLWR_V1 = 536853855
	Contents of DBLWR_VER. More...
constexpr ulint	DBLWR_V1_SPACE_ID_STORED_N = 1783657386
	Contents of DBLWR_V1_SPACE_ID_STORED. More...
constexpr uint32_t	SYNC_PAGE_FLUSH_SLOTS = 512
	DBLWR file pages reserved per instance for single page flushes. More...
std::string	dblwr::dir {"."}
	Double write files location. More...
ulong	dblwr::n_files {1}
	Number of files to use for the double write buffer. More...
ulong	dblwr::batch_size {}
	Maximum number of pages to write in one batch. More...
ulong	dblwr::n_pages {64}
	Number of pages per doublewrite thread/segment. More...
ulong	dblwr::g_mode {Mode::ON}
	DBLWR mode. More...
bool	dblwr::is_reduced_inited = false
	true if DETECT_ONLY (aka reduced) mode is inited More...
static page_no_t	dblwr::LEGACY_PAGE1
	Legacy dblwr buffer first segment page number. More...
static page_no_t	dblwr::LEGACY_PAGE2
	Legacy dblwr buffer second segment page number. More...
page_id_t	dblwr::Force_crash {UINT32_UNDEFINED, UINT32_UNDEFINED}
	Crash the server after writing this page to the data file. More...

Detailed Description

Atomic writes handling.

Function Documentation

dblwr_file_open()

static dberr_t dblwr_file_open ( const std::string &  dir_name, int  id, dblwr::File &  file, ulint  file_type, ib_file_suffix  extension = DWR  )

staticnoexcept

Create the file and or open it if it exists.

Parameters

[in]	dir_name	Directory where to create the file.
[in]	id	Instance ID.
[out]	file	File handle.
[in]	file_type	The file type.
[in]	extension	.dblwr/.bdblwr

Returns

DB_SUCCESS if all went well.

is_buffer_pool_size_ok()

static bool is_buffer_pool_size_ok ( )

staticnoexcept

is_dblwr_page_corrupted()

static bool is_dblwr_page_corrupted ( byte *  page, fil_space_t *  space, page_no_t  page_no, dberr_t *  err  )

staticnoexcept

Check if the dblwr page is corrupted.

Parameters

[in]	page	the dblwr page.
[in]	space	tablespace to which the page belongs.
[in]	page_no	page_no within the actual tablespace.
[out]	err	error code to check if decryption or decompression failed.

Returns

true if dblwr page is corrupted, false otherwise.

Variable Documentation

DBLWR_V1

constexpr ulint DBLWR_V1 = 536853855

constexpr

Contents of DBLWR_VER.

Legacy version, stores the blocks in the system tablespace.

DBLWR_V1_FSEG

constexpr ulint DBLWR_V1_FSEG = 0

constexpr

Doublewrite buffer.

fseg header of the fseg containing the doublewrite buffer

DBLWR_V1_REPEAT

constexpr ulint DBLWR_V1_REPEAT = 12

constexpr

We repeat DBLWR_VER, DBLWR_V1_BLOCK1, DBLWR_V1_BLOCK2 so that if the trx sys header is half-written to disk, we still may be able to recover the information.

DBLWR_V1_SPACE_ID_STORED

constexpr ulint DBLWR_V1_SPACE_ID_STORED = (24 + FSEG_HEADER_SIZE)

constexpr

If this is not yet set to DBLWR_V1_SPACE_ID_STORED_N, we must reset the doublewrite buffer, because starting from 4.1.x the space id of a data page is stored into FIL_PAGE_ARCH_LOG_NO_OR_SPACE_ID.

DBLWR_V1_SPACE_ID_STORED_N

constexpr ulint DBLWR_V1_SPACE_ID_STORED_N = 1783657386

constexpr

Contents of DBLWR_V1_SPACE_ID_STORED.

SYNC_PAGE_FLUSH_SLOTS

constexpr uint32_t SYNC_PAGE_FLUSH_SLOTS = 512

constexpr

DBLWR file pages reserved per instance for single page flushes.