mariadb/storage/innobase/include/fsp0sysspace.h
Thirunarayanan Balathandayuthapani f9003c73a1 MDEV-14795 InnoDB system tablespace cannot be shrunk
- Introduce the option :autoshrink attribute to be
added to innodb_data_file_path variable to allow
the shrinking of system tablespace during startup process.

Steps for shrinking the system tablespace:

1) Find the last used extent in system tablespace
by iterating through the BITMAP in extent descriptor pages

2) If the last used extent is lesser than user specified size
then set desired target size to user specified size.

3) Store the page contents of "to be modified" extent
descriptor pages, latches the "to be modified"
extent descriptor pages and check for buffer pool
memory availability

4) Make checkpoint to flush all pages in buffer pool, so
that pages in flush list doesn't have to use doublewrite
buffer and disable doublewrite buffer during shrinking process

5) Update the FSP_SIZE and FSP_FREE_LIMIT in header page

6) Remove the "to be truncated" pages from FSP_FREE and
FSP_FREE_FRAG list

7) Reset the bitmap in the last descriptor pages for the
"to be truncated" pages.

8) In case of multiple files, calculate the truncated last
file size and do the truncation in last file

9) Check whether mini-transaction log size doesn't exceed
the minimum value of innodb_log_buffer_size which is 2MB.
In that case, replace the modified buffer pool pages with
the page old content.

11) Commit the mini-transaction for shrinking the tablespace
and enable/disable the doublewrite buffer depends on user
specified value.

recv_sys_t::apply(): Handle the truncation of system tablespace
only if the recovered tablespace size is lesser than actual
existing size.
2023-08-01 19:43:04 +05:30

298 lines
8.2 KiB
C++

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/**************************************************//**
@file include/fsp0sysspace.h
Multi file, shared, system tablespace implementation.
Created 2013-7-26 by Kevin Lewis
*******************************************************/
#ifndef fsp0sysspace_h
#define fsp0sysspace_h
#include "fsp0space.h"
/** If the last data file is auto-extended, we add this many pages to it
at a time. We have to make this public because it is a config variable. */
extern uint sys_tablespace_auto_extend_increment;
/** Data structure that contains the information about shared tablespaces.
Currently this can be the system tablespace or a temporary table tablespace */
class SysTablespace : public Tablespace
{
public:
SysTablespace()
:
m_auto_extend_last_file(),
m_last_file_size_max(),
m_created_new_raw(),
m_is_tablespace_full(false),
m_sanity_checks_done(false)
{
/* No op */
}
~SysTablespace() override
{
shutdown();
}
/** Set tablespace full status
@param[in] is_full true if full */
void set_tablespace_full_status(bool is_full)
{
m_is_tablespace_full = is_full;
}
/** Get tablespace full status
@return true if table is full */
bool get_tablespace_full_status()
{
return(m_is_tablespace_full);
}
/** Set sanity check status
@param[in] status true if sanity checks are done */
void set_sanity_check_status(bool status)
{
m_sanity_checks_done = status;
}
/** Get sanity check status
@return true if sanity checks are done */
bool get_sanity_check_status()
{
return(m_sanity_checks_done);
}
/** Parse the input params and populate member variables.
@param filepath path to data files
@param supports_raw true if it supports raw devices
@return true on success parse */
bool parse_params(const char* filepath, bool supports_raw);
/** Check the data file specification.
@param[out] create_new_db true if a new database
is to be created
@param[in] min_expected_size expected tablespace
size in bytes
@return DB_SUCCESS if all OK else error code */
dberr_t check_file_spec(
bool* create_new_db,
ulint min_expected_tablespace_size);
/** Free the memory allocated by parse() */
void shutdown();
/** Normalize the file size, convert to extents. */
void normalize_size();
/**
@return true if a new raw device was created. */
bool created_new_raw() const
{
return(m_created_new_raw);
}
/**
@return auto_extend value setting */
ulint can_auto_extend_last_file() const
{
return(m_auto_extend_last_file);
}
/** @return auto shrink */
bool can_auto_shrink() const
{
return m_auto_shrink;
}
/** Set the last file size.
@param[in] size the size to set */
void set_last_file_size(uint32_t size)
{
ut_ad(!m_files.empty());
m_files.back().m_size = size;
}
/** Get the size of the last data file in the tablespace
@return the size of the last data file in the array */
uint32_t last_file_size() const
{
ut_ad(!m_files.empty());
return(m_files.back().m_size);
}
/**
@return the autoextend increment in pages. */
uint32_t get_autoextend_increment() const
{
return sys_tablespace_auto_extend_increment
<< (20 - srv_page_size_shift);
}
/**
@return user specified tablespace size */
uint32_t get_min_size() const
{
uint32_t full_size= 0;
for (uint32_t i= 0; i < m_files.size(); i++)
full_size+= m_files.at(i).m_user_param_size;
return full_size;
}
/**
@return next increment size */
uint32_t get_increment() const;
/** Open or create the data files
@param[in] is_temp whether this is a temporary tablespace
@param[in] create_new_db whether we are creating a new database
@param[out] sum_new_sizes sum of sizes of the new files added
@return DB_SUCCESS or error code */
dberr_t open_or_create(
bool is_temp,
bool create_new_db,
ulint* sum_new_sizes)
MY_ATTRIBUTE((warn_unused_result));
private:
/** Check the tablespace header for this tablespace.
@return DB_SUCCESS or error code */
inline dberr_t read_lsn_and_check_flags();
/**
@return true if the last file size is valid. */
bool is_valid_size() const
{
return(m_last_file_size_max >= last_file_size());
}
/**
@return true if configured to use raw devices */
bool has_raw_device();
/** Note that the data file was not found.
@param[in] file data file object
@param[out] create_new_db true if a new instance to be created
@return DB_SUCESS or error code */
dberr_t file_not_found(Datafile& file, bool* create_new_db);
/** Note that the data file was found.
@param[in,out] file data file object
@return true if a new instance to be created */
bool file_found(Datafile& file);
/** Create a data file.
@param[in,out] file data file object
@return DB_SUCCESS or error code */
dberr_t create(Datafile& file);
/** Create a data file.
@param[in,out] file data file object
@return DB_SUCCESS or error code */
dberr_t create_file(Datafile& file);
/** Open a data file.
@param[in,out] file data file object
@return DB_SUCCESS or error code */
dberr_t open_file(Datafile& file);
/** Set the size of the file.
@param[in,out] file data file object
@return DB_SUCCESS or error code */
dberr_t set_size(Datafile& file);
/** Convert a numeric string that optionally ends in G or M, to a
number containing megabytes.
@param[in] ptr string with a quantity in bytes
@param[out] megs the number in megabytes
@return next character in string */
static char* parse_units(char* ptr, ulint* megs);
private:
enum file_status_t {
FILE_STATUS_VOID = 0, /** status not set */
FILE_STATUS_RW_PERMISSION_ERROR,/** permission error */
FILE_STATUS_READ_WRITE_ERROR, /** not readable/writable */
FILE_STATUS_NOT_REGULAR_FILE_ERROR /** not a regular file */
};
/** Verify the size of the physical file
@param[in] file data file object
@return DB_SUCCESS if OK else error code. */
dberr_t check_size(Datafile& file);
/** Check if a file can be opened in the correct mode.
@param[in,out] file data file object
@param[out] reason exact reason if file_status check failed.
@return DB_SUCCESS or error code. */
dberr_t check_file_status(
const Datafile& file,
file_status_t& reason);
/* DATA MEMBERS */
/** if true, then we auto-extend the last data file */
bool m_auto_extend_last_file;
/** maximum size of the last data file (0=unlimited) */
ulint m_last_file_size_max;
/** If the following is true we do not allow
inserts etc. This protects the user from forgetting
the 'newraw' keyword to my.cnf */
bool m_created_new_raw;
/** Tablespace full status */
bool m_is_tablespace_full;
/** if false, then sanity checks are still pending */
bool m_sanity_checks_done;
/** Shrink the system tablespace if the value is
enabled */
bool m_auto_shrink;
};
/* GLOBAL OBJECTS */
/** The control info of the system tablespace. */
extern SysTablespace srv_sys_space;
/** The control info of a temporary table shared tablespace. */
extern SysTablespace srv_tmp_space;
/** Check if the space_id is for a system-tablespace (shared + temp).
@param[in] id Space ID to check
@return true if id is a system tablespace, false if not. */
inline bool is_system_tablespace(uint32_t id)
{
return id == TRX_SYS_SPACE || id == SRV_TMP_SPACE_ID;
}
/** Check if predefined shared tablespace.
@return true if predefined shared tablespace */
inline bool is_predefined_tablespace(uint32_t id)
{
return is_system_tablespace(id) || srv_is_undo_tablespace(id);
}
#endif /* fsp0sysspace_h */