dd::bootstrap Namespace Reference

Classes
class	DD_bootstrap_ctx

Enumerations
enum class	Stage {   NOT_STARTED , STARTED , CREATED_TABLESPACES , FETCHED_PROPERTIES ,   CREATED_TABLES , SYNCED , UPGRADED_TABLES , POPULATED ,   STORED_DD_META_DATA , VERSION_UPDATED , FINISHED }

Functions
bool	DDSE_dict_init (THD *thd, dict_init_mode_t dict_init_mode, uint version)
	Initialize InnoDB for. More...
bool	initialize_dictionary (THD *thd, Dictionary_impl *d)
	Create mysql schema. More...
bool	initialize (THD *thd)
	Initialize the dictionary while starting the server for the first time. More...
bool	restart_dictionary (THD *thd)
	Initialize the dictionary while restarting the server. More...
void	recover_innodb_upon_upgrade (THD *thd)
	This function is used in case of crash during upgrade. More...
bool	setup_dd_objects_and_collations (THD *thd)
	Initialization and verification of dictionary objects after upgrade, similar to what is done after normal server restart. More...
bool	store_plugin_IS_table_metadata (THD *thd)
	Iterate through all the plugins, and store IS table meta data into dictionary, once during MySQL server bootstrap. More...

Variables
static constexpr uint	DD_VERSION_80011 = 80011
static constexpr uint	DD_VERSION_80012 = 80012
static constexpr uint	DD_VERSION_80013 = 80013
static constexpr uint	DD_VERSION_80014 = 80014
static constexpr uint	DD_VERSION_80015 = 80015
static constexpr uint	DD_VERSION_80016 = 80016
static constexpr uint	DD_VERSION_80017 = 80017
static constexpr uint	DD_VERSION_80021 = 80021
static constexpr uint	DD_VERSION_80022 = 80022
static constexpr uint	DD_VERSION_80023 = 80023
static constexpr uint	DD_VERSION_80200 = 80200
static constexpr uint	DD_VERSION_80300 = 80300
static std::set< uint >	supported_dd_versions
static constexpr uint	SERVER_VERSION_50700 = 50700
static constexpr uint	SERVER_VERSION_80011 = 80011
static constexpr uint	SERVER_VERSION_80013 = 80013
static constexpr uint	SERVER_VERSION_80014 = 80014
static constexpr uint	SERVER_VERSION_80015 = 80015
static constexpr uint	SERVER_VERSION_80016 = 80016
static constexpr uint	SERVER_VERSION_80400 = 80400
static std::set< uint >	unsupported_server_versions = {}

Enumeration Type Documentation

Stage

enum class dd::bootstrap::Stage

strong

Enumerator
NOT_STARTED
STARTED
CREATED_TABLESPACES
FETCHED_PROPERTIES
CREATED_TABLES
SYNCED
UPGRADED_TABLES
POPULATED
STORED_DD_META_DATA
VERSION_UPDATED
FINISHED

Function Documentation

DDSE_dict_init()

bool dd::bootstrap::DDSE_dict_init	(	THD *	thd,
		dict_init_mode_t	dict_init_mode,
		uint	version
	)

Initialize InnoDB for.

• creating new data directory : InnoDB creates system tablespace and dictionary tablespace.
• normal server restart. : Verifies existence of system and dictionary tablespaces.
• in place upgrade : Verifies existence of system tablespace and create dictionary tablespace.

Parameters

thd	Thread context.
dict_init_mode	mode to initialize InnoDB
version	Dictionary version.

Returns

Upon failure, return true, otherwise false.

initialize()

bool dd::bootstrap::initialize

(

THD *

thd

)

Initialize the dictionary while starting the server for the first time.

At this point, the DDSE has been initialized as a normal plugin. The dictionary initialization proceeds as follows:

1. Preparation phase

1.1 Call dict_init() to initialize the DDSE. This will make the predefined tablespaces be created physically, and their meta data be returned to the SQL layer along with the meta data for the DD tables required by the DDSE. The tables are not yet created physically. 1.2 Prepare the dd::Tablespace objects reflecting the predefined tablespace objects and add them to the core registry in the storage adapter.

1. Scaffolding phase

2.1 Create and use the dictionary schema by executing SQL statements. The schema is created physically since this is the first time start, and the meta data is generated and stored in the core registry of the storage adapter without being written to disk. 2.2 Create tables by executing SQL statements. Like for the schema, the tables are created physically, and the meta data is generated and stored in the core registry without being written to disk. This is done to prepare enough meta data to actually be able to open the DD tables.

1. Synchronization phase

3.1 Store meta data for the DD schema, tablespace and tables, i.e., the DD objects that were generated in the scaffolding phase, and make sure the IDs are maintained when the objects are stored. 3.2 Populate the DD tables which have some predefined static contents to be inserted. This is, e.g., relevant for the 'catalogs' table, which only has a single default entry in it. Dynamic contents is added in other ways, e.g. by storing generated DD objects (see above) or by inserting data from other sources (see re-population of character sets in the context of server restart below). 3.3 Store various properties of the DD tables, including the SE private data, a representation of the DDL statement used to create the table etc. 3.4 Verify that the dictionary objects representing the core DD table meta data are present in the core registry of the storage adapter. If an object representing the meta data of a core DD table is not available, then we loose access to the DD tables, and we will not be able to handle cache misses or updates to the meta data. 3.5 Update the version numbers that are stored, e.g. the DD version and the current mysqld server version.

Parameters

thd	Thread context.

Returns

Upon failure, return true, otherwise false.

initialize_dictionary()

bool dd::bootstrap::initialize_dictionary	(	THD *	thd,
		Dictionary_impl *	d
	)

Create mysql schema.

Create dictionary tables inside InnoDB. Create entry for dictionary tables inside dictionary tables. Add hard coded data to dictionary tables. Create Foreign key constraint on dictionary tables.

This function is used in both cases, new data directory initialization and in place upgrade.

Parameters

thd	Thread context.
d	Dictionary instance

Returns

Upon failure, return true, otherwise false.

recover_innodb_upon_upgrade()

void dd::bootstrap::recover_innodb_upon_upgrade

(

THD *

thd

)

This function is used in case of crash during upgrade.

It tries to initialize dictionary and calls DDSE_dict_recover. InnoDB should do the recovery and empty undo log. Upgrade process will do the cleanup and exit.

Parameters

thd	Thread context.

restart_dictionary()

bool dd::bootstrap::restart_dictionary

(

THD *

thd

)

Initialize the dictionary while restarting the server.

At this point, the DDSE has been initialized as a normal plugin. The dictionary initialization proceeds as follows:

1. Preparation phase

1.1 Call dict_init() to initialize the DDSE. This will retrieve the meta data of the predefined tablespaces and the DD tables required by the DDSE. Both the tables and the tablespaces are already created physically, the point here is just to get hold of enough meta data to start using the DD. 1.2 Prepare the dd::Tablespace objects reflecting the predefined tablespace objects and add them to the core registry in the storage adapter.

1. Scaffolding phase

2.1 Create and use the dictionary schema by executing SQL statements. The schema is not created physically, but the meta data is generated and stored in the core registry without being written to disk. 2.2 Create tables by executing SQL statements. Like for the schema, the tables are not created physically, but the meta data is generated and stored in the core registry without being written to disk. This is done to prepare enough meta data to actually be able to open the DD tables. The SQL DDL statements are either retrieved from the table definitions that are part of the server binary (for restart), or from one of the DD tables (for upgrade).

1. Synchronization phase

3.1 Read meta data for the DD tables from the DD tables. Here, we use the meta data from the scaffolding phase for the schema, tablespace and the DD tables to open the physical DD tables. We read the stored objects, and update the in-memory copies in the core registry with the real meta data from the objects that are retrieved form persistent storage. Finally, we flush the tables to empty the table definition cache to make sure the table share structures for the DD tables are re-created based on the actual meta data that was read from disk rather than the temporary meta data from the scaffolding phase. 3.2 If this is a restart with a new DD version, we must upgrade the DD tables. In that case, we create the new target DD tables in a temporary schema, migrate the meta data to the new tables, and then do DML on the DD tables to make sure the new DD tables will be used instead of the old ones. This DML involves changing the schema ids directly in the DD tables, and updating the meta data stored in the 'dd_properties' DD table. This will make sure the switch from the old to the new tables is atomic. After this is done, we will reset the DD cache and start over the initialization from step 1.2. Then, the new DD tables will be used, and a normal restart will be done. 3.3 Re-populate character sets and collations: The character set and collation information is read from files and added to a server internal data structure when the server starts. This data structure is, in turn, used to populate the corresponding DD tables. The tables must be re-populated on each server start if new character sets or collations have been added. However, we can not do this if in read only mode. 3.4 Verify that the dictionary objects representing the core DD table meta data are present in the core registry of the storage adapter. If an object representing the meta data of a core DD table is not available, then we loose access to the DD tables, and we will not be able to handle cache misses or updates to the meta data. 3.5 If an upgrade was done, the persistent version numbers are updated, e.g. the DD version and the current mysqld server version.

Parameters

thd	Thread context.

Returns

Upon failure, return true, otherwise false.

setup_dd_objects_and_collations()

bool dd::bootstrap::setup_dd_objects_and_collations

(

THD *

thd

)

Initialization and verification of dictionary objects after upgrade, similar to what is done after normal server restart.

Parameters

thd	Thread context

store_plugin_IS_table_metadata()

bool dd::bootstrap::store_plugin_IS_table_metadata

(

THD *

thd

)

Iterate through all the plugins, and store IS table meta data into dictionary, once during MySQL server bootstrap.

Parameters

thd	Thread context.

Returns

Upon failure, return true, otherwise false.

Variable Documentation

DD_VERSION_80011

constexpr uint dd::bootstrap::DD_VERSION_80011 = 80011

staticconstexpr

DD_VERSION_80012

constexpr uint dd::bootstrap::DD_VERSION_80012 = 80012

staticconstexpr

DD_VERSION_80013

constexpr uint dd::bootstrap::DD_VERSION_80013 = 80013

staticconstexpr

DD_VERSION_80014

constexpr uint dd::bootstrap::DD_VERSION_80014 = 80014

staticconstexpr

DD_VERSION_80015

constexpr uint dd::bootstrap::DD_VERSION_80015 = 80015

staticconstexpr

DD_VERSION_80016

constexpr uint dd::bootstrap::DD_VERSION_80016 = 80016

staticconstexpr

DD_VERSION_80017

constexpr uint dd::bootstrap::DD_VERSION_80017 = 80017

staticconstexpr

DD_VERSION_80021

constexpr uint dd::bootstrap::DD_VERSION_80021 = 80021

staticconstexpr

DD_VERSION_80022

constexpr uint dd::bootstrap::DD_VERSION_80022 = 80022

staticconstexpr

DD_VERSION_80023

constexpr uint dd::bootstrap::DD_VERSION_80023 = 80023

staticconstexpr

DD_VERSION_80200

constexpr uint dd::bootstrap::DD_VERSION_80200 = 80200

staticconstexpr

DD_VERSION_80300

constexpr uint dd::bootstrap::DD_VERSION_80300 = 80300

staticconstexpr

SERVER_VERSION_50700

constexpr uint dd::bootstrap::SERVER_VERSION_50700 = 50700

staticconstexpr

SERVER_VERSION_80011

constexpr uint dd::bootstrap::SERVER_VERSION_80011 = 80011

staticconstexpr

SERVER_VERSION_80013

constexpr uint dd::bootstrap::SERVER_VERSION_80013 = 80013

staticconstexpr

SERVER_VERSION_80014

constexpr uint dd::bootstrap::SERVER_VERSION_80014 = 80014

staticconstexpr

SERVER_VERSION_80015

constexpr uint dd::bootstrap::SERVER_VERSION_80015 = 80015

staticconstexpr

SERVER_VERSION_80016

constexpr uint dd::bootstrap::SERVER_VERSION_80016 = 80016

staticconstexpr

SERVER_VERSION_80400

constexpr uint dd::bootstrap::SERVER_VERSION_80400 = 80400

staticconstexpr

supported_dd_versions

std::set<uint> dd::bootstrap::supported_dd_versions

static

Initial value:

= {
    DD_VERSION_80011, DD_VERSION_80012, DD_VERSION_80013, DD_VERSION_80014,
    DD_VERSION_80015, DD_VERSION_80016, DD_VERSION_80017, DD_VERSION_80021,
    DD_VERSION_80022, DD_VERSION_80023, DD_VERSION_80200}

unsupported_server_versions

std::set<uint> dd::bootstrap::unsupported_server_versions = {}

static