MaxScale/server/modules/include/schemarouter.h
2015-04-23 21:00:52 +03:00

322 lines
12 KiB
C

#ifndef _SCHEMAROUTER_H
#define _SCHEMAROUTER_H
/*
* This file is distributed as part of the MariaDB Corporation MaxScale. It is free
* software: you can redistribute it and/or modify it under the terms of the
* GNU General Public License as published by the Free Software Foundation,
* version 2.
*
* This program is distributed in the hope that it will be useful, but WITHOUT
* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
* FOR A PARTICULAR PURPOSE. See the GNU General Public License for more
* details.
*
* You should have received a copy of the GNU General Public License along with
* this program; if not, write to the Free Software Foundation, Inc., 51
* Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
*
* Copyright MariaDB Corporation Ab 2013-2014
*/
/**
* @file schemarouter.h - The schemarouter router module header file
*
* @verbatim
* Revision History
*
* See GitHub https://github.com/mariadb-corporation/MaxScale
*
* @endverbatim
*/
#include <dcb.h>
#include <hashtable.h>
#include <mysql_client_server_protocol.h>
/**
* Bitmask values for the router session's initialization. These values are used
* to prevent responses from internal commands being forwarded to the client.
*/
typedef enum init_mask
{
INIT_READY = 0x0,
INIT_MAPPING = 0x1,
INIT_USE_DB = 0x02,
INIT_UNINT = 0x04
} init_mask_t;
/**
* The state of the backend server reference
*/
typedef enum bref_state {
BREF_IN_USE = 0x01,
BREF_WAITING_RESULT = 0x02, /*< for session commands only */
BREF_QUERY_ACTIVE = 0x04, /*< for other queries */
BREF_CLOSED = 0x08,
BREF_DB_MAPPED = 0x10
} bref_state_t;
#define BREF_IS_NOT_USED(s) ((s)->bref_state & ~BREF_IN_USE)
#define BREF_IS_IN_USE(s) ((s)->bref_state & BREF_IN_USE)
#define BREF_IS_WAITING_RESULT(s) ((s)->bref_num_result_wait > 0)
#define BREF_IS_QUERY_ACTIVE(s) ((s)->bref_state & BREF_QUERY_ACTIVE)
#define BREF_IS_CLOSED(s) ((s)->bref_state & BREF_CLOSED)
#define BREF_IS_MAPPED(s) ((s)->bref_mapped)
/**
* The type of the backend server
*/
typedef enum backend_type_t {
BE_UNDEFINED=-1,
BE_MASTER,
BE_JOINED = BE_MASTER,
BE_SLAVE,
BE_COUNT
} backend_type_t;
struct router_instance;
/**
* Route target types
*/
typedef enum {
TARGET_UNDEFINED = 0x00,
TARGET_MASTER = 0x01,
TARGET_SLAVE = 0x02,
TARGET_NAMED_SERVER = 0x04,
TARGET_ALL = 0x08,
TARGET_RLAG_MAX = 0x10,
TARGET_ANY = 0x20
} route_target_t;
#define TARGET_IS_UNDEFINED(t) (t == TARGET_UNDEFINED)
#define TARGET_IS_NAMED_SERVER(t) (t & TARGET_NAMED_SERVER)
#define TARGET_IS_ALL(t) (t & TARGET_ALL)
#define TARGET_IS_ANY(t) (t & TARGET_ANY)
typedef struct rses_property_st rses_property_t;
typedef struct router_client_session ROUTER_CLIENT_SES;
/**
* Router session properties
*/
typedef enum rses_property_type_t {
RSES_PROP_TYPE_UNDEFINED=-1,
RSES_PROP_TYPE_SESCMD=0,
RSES_PROP_TYPE_FIRST = RSES_PROP_TYPE_SESCMD,
RSES_PROP_TYPE_TMPTABLES,
RSES_PROP_TYPE_LAST=RSES_PROP_TYPE_TMPTABLES,
RSES_PROP_TYPE_COUNT=RSES_PROP_TYPE_LAST+1
} rses_property_type_t;
/** default values for rwsplit configuration parameters */
#define CONFIG_MAX_SLAVE_CONN 1
#define CONFIG_MAX_SLAVE_RLAG -1 /*< not used */
#define CONFIG_SQL_VARIABLES_IN TYPE_ALL
#define GET_SELECT_CRITERIA(s) \
(strncmp(s,"LEAST_GLOBAL_CONNECTIONS", strlen("LEAST_GLOBAL_CONNECTIONS")) == 0 ? \
LEAST_GLOBAL_CONNECTIONS : ( \
strncmp(s,"LEAST_BEHIND_MASTER", strlen("LEAST_BEHIND_MASTER")) == 0 ? \
LEAST_BEHIND_MASTER : ( \
strncmp(s,"LEAST_ROUTER_CONNECTIONS", strlen("LEAST_ROUTER_CONNECTIONS")) == 0 ? \
LEAST_ROUTER_CONNECTIONS : ( \
strncmp(s,"LEAST_CURRENT_OPERATIONS", strlen("LEAST_CURRENT_OPERATIONS")) == 0 ? \
LEAST_CURRENT_OPERATIONS : UNDEFINED_CRITERIA))))
/**
* Session variable command
*/
typedef struct mysql_sescmd_st {
#if defined(SS_DEBUG)
skygw_chk_t my_sescmd_chk_top;
#endif
rses_property_t* my_sescmd_prop; /*< Parent property */
GWBUF* my_sescmd_buf; /*< Query buffer */
unsigned char my_sescmd_packet_type;/*< Packet type */
bool my_sescmd_is_replied; /*< Is cmd replied to client */
int position; /*< Position of this command */
#if defined(SS_DEBUG)
skygw_chk_t my_sescmd_chk_tail;
#endif
} mysql_sescmd_t;
/**
* Property structure
*/
struct rses_property_st {
#if defined(SS_DEBUG)
skygw_chk_t rses_prop_chk_top;
#endif
ROUTER_CLIENT_SES* rses_prop_rsession; /*< Parent router session */
int rses_prop_refcount; /*< Reference count*/
rses_property_type_t rses_prop_type; /*< Property type */
union rses_prop_data {
mysql_sescmd_t sescmd; /*< Session commands */
HASHTABLE* temp_tables; /*< Hashtable of table names */
} rses_prop_data;
rses_property_t* rses_prop_next; /*< Next property of same type */
#if defined(SS_DEBUG)
skygw_chk_t rses_prop_chk_tail;
#endif
};
typedef struct sescmd_cursor_st {
#if defined(SS_DEBUG)
skygw_chk_t scmd_cur_chk_top;
#endif
ROUTER_CLIENT_SES* scmd_cur_rses; /*< pointer to owning router session */
rses_property_t** scmd_cur_ptr_property; /*< address of pointer to owner property */
mysql_sescmd_t* scmd_cur_cmd; /*< pointer to current session command */
bool scmd_cur_active; /*< true if command is being executed */
int position; /*< Position of this cursor */
#if defined(SS_DEBUG)
skygw_chk_t scmd_cur_chk_tail;
#endif
} sescmd_cursor_t;
/**
* Internal structure used to define the set of backend servers we are routing
* connections to. This provides the storage for routing module specific data
* that is required for each of the backend servers.
*
* Owned by router_instance, referenced by each routing session.
*/
typedef struct backend_st {
#if defined(SS_DEBUG)
skygw_chk_t be_chk_top;
#endif
SERVER* backend_server; /*< The server itself */
int backend_conn_count; /*< Number of connections to
* the server
*/
bool be_valid; /*< Valid when belongs to the
* router's configuration
*/
int weight; /*< Desired weighting on the
* load. Expressed in .1%
* increments
*/
struct stats{
int queries;
} stats;
#if defined(SS_DEBUG)
skygw_chk_t be_chk_tail;
#endif
} BACKEND;
/**
* Reference to BACKEND.
*
* Owned by router client session.
*/
typedef struct backend_ref_st {
#if defined(SS_DEBUG)
skygw_chk_t bref_chk_top;
#endif
int n_mapping_eof;
GWBUF* map_queue;
BACKEND* bref_backend; /*< Backend server */
DCB* bref_dcb; /*< Backend DCB */
bref_state_t bref_state; /*< State of the backend */
bool bref_mapped; /*< Whether the backend has been mapped */
bool last_sescmd_replied;
int bref_num_result_wait; /*< Number of not yet received results */
sescmd_cursor_t bref_sescmd_cur; /*< Session command cursor */
GWBUF* bref_pending_cmd; /*< For stmt which can't be routed due active sescmd execution */
#if defined(SS_DEBUG)
skygw_chk_t bref_chk_tail;
#endif
} backend_ref_t;
/**
* Configuration values
*/
typedef struct schemarouter_config_st {
int rw_max_slave_conn_percent;
int rw_max_slave_conn_count;
target_t rw_use_sql_variables_in;
int max_sescmd_hist;
bool disable_sescmd_hist;
} schemarouter_config_t;
/**
* The statistics for this router instance
*/
typedef struct {
int n_queries; /*< Number of queries forwarded */
int n_sescmd; /*< Number of session commands */
int longest_sescmd; /*< Longest chain of stored session commands */
int n_hist_exceeded;/*< Number of sessions that exceeded session
* command history limit */
int sessions;
double ses_longest; /*< Longest session */
double ses_shortest; /*< Shortest session */
double ses_average; /*< Average session length */
} ROUTER_STATS;
/**
* The client session structure used within this router.
*/
struct router_client_session {
#if defined(SS_DEBUG)
skygw_chk_t rses_chk_top;
#endif
SPINLOCK rses_lock; /*< protects rses_deleted */
int rses_versno; /*< even = no active update, else odd. not used 4/14 */
bool rses_closed; /*< true when closeSession is called */
DCB* rses_client_dcb;
MYSQL_session* rses_mysql_session; /*< Session client data (username, password, SHA1). */
/** Properties listed by their type */
rses_property_t* rses_properties[RSES_PROP_TYPE_COUNT]; /*< Session properties */
backend_ref_t* rses_master_ref; /*< Router session master reference */
backend_ref_t* rses_backend_ref; /*< Pointer to backend reference array */
schemarouter_config_t rses_config; /*< Copied config info from router instance */
int rses_nbackends; /*< Number of backends */
int rses_capabilities; /*< Input type, for example */
bool rses_autocommit_enabled; /*< Is autocommit enabled */
bool rses_transaction_active; /*< Is a transaction active */
struct router_instance *router; /*< The router instance */
struct router_client_session* next; /*< List of router sessions */
HASHTABLE* dbhash; /*< Database hash containing names of the databases mapped to the servers that contain them */
char connect_db[MYSQL_DATABASE_MAXLEN+1]; /*< Database the user was trying to connect to */
init_mask_t init; /*< Initialization state bitmask */
GWBUF* queue; /*< Query that was received before the session was ready */
DCB* dcb_route; /*< Internal DCB used to trigger re-routing of buffers */
DCB* dcb_reply; /*< Internal DCB used to send replies to the client */
ROUTER_STATS stats; /*< Statistics for this router */
int n_sescmd;
int pos_generator;
#if defined(SS_DEBUG)
skygw_chk_t rses_chk_tail;
#endif
};
/**
* The per instance data for the router.
*/
typedef struct router_instance {
SERVICE* service; /*< Pointer to service */
ROUTER_CLIENT_SES* connections; /*< List of client connections */
SPINLOCK lock; /*< Lock for the instance data */
BACKEND** servers; /*< Backend servers */
BACKEND* master; /*< NULL or pointer */
schemarouter_config_t schemarouter_config; /*< expanded config info from SERVICE */
int schemarouter_version;/*< version number for router's config */
unsigned int bitmask; /*< Bitmask to apply to server->status */
unsigned int bitvalue; /*< Required value of server->status */
ROUTER_STATS stats; /*< Statistics for this router */
struct router_instance* next; /*< Next router on the list */
bool available_slaves; /*< The router has some slaves available */
} ROUTER_INSTANCE;
#define BACKEND_TYPE(b) (SERVER_IS_MASTER((b)->backend_server) ? BE_MASTER : \
(SERVER_IS_SLAVE((b)->backend_server) ? BE_SLAVE : BE_UNDEFINED));
#endif /*< _SCHEMAROUTER_H */