log0chkp.cc File Reference

#include "log0chkp.h"
#include <chrono>
#include <cstring>
#include "arch0arch.h"
#include "buf0buf.h"
#include "buf0flu.h"
#include "fil0pages_persistence_interface.h"
#include "log0buf.h"
#include "log0encryption.h"
#include "log0files_io.h"
#include "log0log.h"
#include "log0recv.h"
#include "log0handler_interface.h"
#include "log0sys.h"
#include "log0test.h"
#include "log0types.h"
#include "log0write.h"
#include "mach0data.h"
#include "my_dbug.h"
#include "os0event.h"
#include "os0thread-create.h"
#include "sql_thd_internal_api.h"
#include "srv0mon.h"
#include "srv0srv.h"
#include "srv0start.h"
#include "ut0byte.h"

Functions
static void	log_wait_for_checkpoint (lsn_t lsn)
	Waits for checkpoint advanced to at least that lsn. More...
static void	log_request_sync_flush ()
	Requests for urgent flush of dirty pages, to advance oldest_lsn in flush lists. More...
static lsn_t	log_compute_available_for_checkpoint_lsn ()
	Calculates lsn at which we might write a next checkpoint. More...
dberr_t	log_files_next_checkpoint (log_t &log, lsn_t next_checkpoint_lsn)
	Writes the next checkpoint to the log file, by writing a single checkpoint header with the checkpoint lsn. More...
Log_checkpoint_header_no	log_next_checkpoint_header (Log_checkpoint_header_no checkpoint_header_no)
	Provides opposite checkpoint header number to the given checkpoint header number. More...
dberr_t	log_files_write_checkpoint_low (log_t &log, Log_file_handle &checkpoint_file_handle, Log_checkpoint_header_no checkpoint_header_no, lsn_t checkpoint_lsn)
	Writes checkpoint to the file containing the written checkpoint_lsn. More...
dberr_t	log_files_write_first_data_block_low (log_t &log, Log_file_handle &file_handle, lsn_t checkpoint_lsn, lsn_t file_start_lsn)
	Writes the first data block to the log file using the provided handle to the opened log file. More...
static bool	log_request_checkpoint_validate ()
	Check if the checkpointing is enabled. More...
static lsn_t	get_soft_logical_capacity ()
static lsn_t	adaptive_flush_max_age (lsn_t soft_logical_capacity)
static lsn_t	adaptive_flush_min_age (lsn_t soft_logical_capacity)
static lsn_t	aggressive_checkpoint_min_age (lsn_t soft_logical_capacity)
void	log_update_exported_lsns ()
	Updates: More...

Variables
Log_checkpointing *	log_checkpointing
	Redo log checkpointing. More...

Function Documentation

adaptive_flush_max_age()

static lsn_t adaptive_flush_max_age ( lsn_t  soft_logical_capacity )

static

adaptive_flush_min_age()

static lsn_t adaptive_flush_min_age ( lsn_t  soft_logical_capacity )

static

aggressive_checkpoint_min_age()

static lsn_t aggressive_checkpoint_min_age ( lsn_t  soft_logical_capacity )

static

get_soft_logical_capacity()

static lsn_t get_soft_logical_capacity ( )

static

log_compute_available_for_checkpoint_lsn()

static lsn_t log_compute_available_for_checkpoint_lsn ( )

static

Calculates lsn at which we might write a next checkpoint.

It does the best effort, but possibly the maximum allowed lsn, could be even bigger. That's because the order of dirty pages in flush lists has been relaxed, and we don't want to spend time on traversing the whole flush lists here.

Note that some flush lists could be empty, and some additions of dirty pages could be pending (threads have written data to the log buffer and became scheduled out just before adding the dirty pages). That's why the calculated value cannot be larger than the buf_flush_list_added->smallest_not_added_lsn() (only up to this lsn value we are sure, that all the dirty pages have been added).

It is guaranteed, that the returned value will not be smaller than the log_checkpointer.m_checkpoint_lsn.

Returns

lsn for which we might write the checkpoint

log_files_next_checkpoint()

dberr_t log_files_next_checkpoint	(	log_t &	log,
		lsn_t	lsn
	)

Writes the next checkpoint to the log file, by writing a single checkpoint header with the checkpoint lsn.

Flushes the file after the write and updates the log.last_checkpoint_lsn.

Remarks

Note that two checkpoint headers are used alternately for consecutive checkpoints. If InnoDB crashed during the write, it would still have the previous checkpoint info and recovery would work.

Parameters

[in,out]	log	redo log
[in]	lsn	writes checkpoint at this lsn

Returns

DB_SUCCESS or error

log_files_write_checkpoint_low()

dberr_t log_files_write_checkpoint_low	(	log_t &	log,
		Log_file_handle &	checkpoint_file_handle,
		Log_checkpoint_header_no	checkpoint_header_no,
		lsn_t	next_checkpoint_lsn
	)

Writes checkpoint to the file containing the written checkpoint_lsn.

The checkpoint is written to the given checkpoint header. Unless InnoDB is starting: checkpointer, writer and files mutexes must be acquired before calling this function.

Parameters

[in,out]	log	redo log
[in]	checkpoint_file_handle	handle to opened file
[in]	checkpoint_header_no	checkpoint header to be written
[in]	next_checkpoint_lsn	the checkpoint lsn to write

Returns

DB_SUCCESS or error

log_files_write_first_data_block_low()

dberr_t log_files_write_first_data_block_low	(	log_t &	log,
		Log_file_handle &	file_handle,
		lsn_t	checkpoint_lsn,
		lsn_t	file_start_lsn
	)

Writes the first data block to the log file using the provided handle to the opened log file.

The block is addressed by the given checkpoint_lsn, filled with 0x00 and its data length points to checkpoint_lsn inside, making the block logically empty.

Remarks

This is used only during creation of new log files.

Parameters

[in,out]	log	redo log
[in]	file_handle	handle to the opened log file
[in]	checkpoint_lsn	the checkpoint lsn
[in]	file_start_lsn	start_lsn of the file

Returns

DB_SUCCESS or error

log_next_checkpoint_header()

Log_checkpoint_header_no log_next_checkpoint_header

(

Log_checkpoint_header_no

checkpoint_header_no

)

Provides opposite checkpoint header number to the given checkpoint header number.

Parameters

[in]

checkpoint_header_no

the given checkpoint header number

Returns

the opposite checkpoint header number

log_request_checkpoint_validate()

static bool log_request_checkpoint_validate ( )

static

Check if the checkpointing is enabled.

Return values

true	checkpointing is enabled
false	checkpointing is disabled

log_request_sync_flush()

static void log_request_sync_flush ( )

static

Requests for urgent flush of dirty pages, to advance oldest_lsn in flush lists.

This should force page cleaners to perform the sync-flush in which case the innodb_max_io_capacity is not respected. This should be called when we are close to running out of space in redo log (close to m_free_check_limit_lsn).

log_update_exported_lsns()

void log_update_exported_lsns

(

)

Updates:

• Innodb_redo_log_checkpoint_lsn,
• Innodb_redo_log_current_lsn,
• Innodb_redo_log_flushed_to_disk_lsn. They should be updated "together", to present a consistent state to the user, that is one in which checkpoint_lsn <= flushed_to_disk_lsn <= current_lsn. Calls are protected by log_checkpointer->limits_mutex, which is to avoid torn writes to these exposed fields, but otherwise does not enforce above inequalities. Instead they follow from loading atomics in the order from the conceptually smallest to the largest - a load synchronizes with the store, which in turn should happen after the conceptually larger atomic already was at least equal to the stored value, so can be only larger now.

log_wait_for_checkpoint()

static void log_wait_for_checkpoint ( lsn_t  lsn )

static

Waits for checkpoint advanced to at least that lsn.

Parameters

[in]

lsn

lsn up to which we are waiting

Variable Documentation

log_checkpointing

Log_checkpointing* log_checkpointing

Redo log checkpointing.