346 lines
12 KiB
C
346 lines
12 KiB
C
#ifndef _RWSPLITROUTER_H
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#define _RWSPLITROUTER_H
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/*
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* This file is distributed as part of the MariaDB Corporation MaxScale. It is free
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* software: you can redistribute it and/or modify it under the terms of the
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* GNU General Public License as published by the Free Software Foundation,
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* version 2.
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*
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* This program is distributed in the hope that it will be useful, but WITHOUT
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* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
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* FOR A PARTICULAR PURPOSE. See the GNU General Public License for more
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* details.
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*
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* You should have received a copy of the GNU General Public License along with
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* this program; if not, write to the Free Software Foundation, Inc., 51
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* Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
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*
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* Copyright MariaDB Corporation Ab 2013-2014
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*/
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/**
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* @file router.h - The read write split router module heder file
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*
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* @verbatim
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* Revision History
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*
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* See GitHub https://github.com/mariadb-corporation/MaxScale
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*
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* @endverbatim
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*/
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#include <dcb.h>
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#include <hashtable.h>
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#include <math.h>
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#undef PREP_STMT_CACHING
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#if defined(PREP_STMT_CACHING)
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typedef enum prep_stmt_type {
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PREP_STMT_NAME,
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PREP_STMT_ID
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} prep_stmt_type_t;
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typedef enum prep_stmt_state {
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PREP_STMT_ALLOC,
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PREP_STMT_SENT,
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PREP_STMT_RECV,
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PREP_STMT_DROPPED
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} prep_stmt_state_t;
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#endif /*< PREP_STMT_CACHING */
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typedef enum bref_state {
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BREF_IN_USE = 0x01,
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BREF_WAITING_RESULT = 0x02, /*< for session commands only */
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BREF_QUERY_ACTIVE = 0x04, /*< for other queries */
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BREF_CLOSED = 0x08,
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BREF_SESCMD_FAILED = 0x10 /*< Backend references that should be dropped */
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} bref_state_t;
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#define BREF_IS_NOT_USED(s) ((s)->bref_state & ~BREF_IN_USE)
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#define BREF_IS_IN_USE(s) ((s)->bref_state & BREF_IN_USE)
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#define BREF_IS_WAITING_RESULT(s) ((s)->bref_num_result_wait > 0)
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#define BREF_IS_QUERY_ACTIVE(s) ((s)->bref_state & BREF_QUERY_ACTIVE)
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#define BREF_IS_CLOSED(s) ((s)->bref_state & BREF_CLOSED)
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#define BREF_HAS_FAILED(s) ((s)->bref_state & BREF_SESCMD_FAILED)
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typedef enum backend_type_t {
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BE_UNDEFINED=-1,
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BE_MASTER,
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BE_JOINED = BE_MASTER,
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BE_SLAVE,
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BE_COUNT
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} backend_type_t;
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struct router_instance;
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typedef enum {
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TARGET_UNDEFINED = 0x00,
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TARGET_MASTER = 0x01,
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TARGET_SLAVE = 0x02,
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TARGET_NAMED_SERVER = 0x04,
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TARGET_ALL = 0x08,
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TARGET_RLAG_MAX = 0x10
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} route_target_t;
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#define TARGET_IS_MASTER(t) (t & TARGET_MASTER)
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#define TARGET_IS_SLAVE(t) (t & TARGET_SLAVE)
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#define TARGET_IS_NAMED_SERVER(t) (t & TARGET_NAMED_SERVER)
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#define TARGET_IS_ALL(t) (t & TARGET_ALL)
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#define TARGET_IS_RLAG_MAX(t) (t & TARGET_RLAG_MAX)
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typedef struct rses_property_st rses_property_t;
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typedef struct router_client_session ROUTER_CLIENT_SES;
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typedef enum rses_property_type_t {
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RSES_PROP_TYPE_UNDEFINED=-1,
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RSES_PROP_TYPE_SESCMD=0,
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RSES_PROP_TYPE_FIRST = RSES_PROP_TYPE_SESCMD,
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RSES_PROP_TYPE_TMPTABLES,
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RSES_PROP_TYPE_LAST=RSES_PROP_TYPE_TMPTABLES,
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RSES_PROP_TYPE_COUNT=RSES_PROP_TYPE_LAST+1
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} rses_property_type_t;
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/**
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* This criteria is used when backends are chosen for a router session's use.
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* Backend servers are sorted to ascending order according to the criteria
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* and top N are chosen.
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*/
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typedef enum select_criteria {
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UNDEFINED_CRITERIA=0,
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LEAST_GLOBAL_CONNECTIONS, /*< all connections established by MaxScale */
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LEAST_ROUTER_CONNECTIONS, /*< connections established by this router */
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LEAST_BEHIND_MASTER,
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LEAST_CURRENT_OPERATIONS,
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DEFAULT_CRITERIA=LEAST_CURRENT_OPERATIONS,
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LAST_CRITERIA /*< not used except for an index */
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} select_criteria_t;
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/** default values for rwsplit configuration parameters */
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#define CONFIG_MAX_SLAVE_CONN 1
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#define CONFIG_MAX_SLAVE_RLAG -1 /*< not used */
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#define CONFIG_SQL_VARIABLES_IN TYPE_ALL
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#define GET_SELECT_CRITERIA(s) \
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(strncmp(s,"LEAST_GLOBAL_CONNECTIONS", strlen("LEAST_GLOBAL_CONNECTIONS")) == 0 ? \
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LEAST_GLOBAL_CONNECTIONS : ( \
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strncmp(s,"LEAST_BEHIND_MASTER", strlen("LEAST_BEHIND_MASTER")) == 0 ? \
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LEAST_BEHIND_MASTER : ( \
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strncmp(s,"LEAST_ROUTER_CONNECTIONS", strlen("LEAST_ROUTER_CONNECTIONS")) == 0 ? \
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LEAST_ROUTER_CONNECTIONS : ( \
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strncmp(s,"LEAST_CURRENT_OPERATIONS", strlen("LEAST_CURRENT_OPERATIONS")) == 0 ? \
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LEAST_CURRENT_OPERATIONS : UNDEFINED_CRITERIA))))
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/**
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* Session variable command
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*/
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typedef struct mysql_sescmd_st {
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#if defined(SS_DEBUG)
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skygw_chk_t my_sescmd_chk_top;
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#endif
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rses_property_t* my_sescmd_prop; /*< parent property */
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GWBUF* my_sescmd_buf; /*< query buffer */
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unsigned char my_sescmd_packet_type;/*< packet type */
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bool my_sescmd_is_replied; /*< is cmd replied to client */
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unsigned char reply_cmd; /*< The reply command. One of OK, ERR, RESULTSET or
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* LOCAL_INFILE. Slave servers are compared to this
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* when they return session command replies.*/
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int position; /*< Position of this command */
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#if defined(SS_DEBUG)
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skygw_chk_t my_sescmd_chk_tail;
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#endif
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} mysql_sescmd_t;
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/**
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* Property structure
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*/
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struct rses_property_st {
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#if defined(SS_DEBUG)
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skygw_chk_t rses_prop_chk_top;
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#endif
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ROUTER_CLIENT_SES* rses_prop_rsession; /*< parent router session */
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int rses_prop_refcount;
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rses_property_type_t rses_prop_type;
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union rses_prop_data {
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mysql_sescmd_t sescmd;
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HASHTABLE* temp_tables;
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} rses_prop_data;
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rses_property_t* rses_prop_next; /*< next property of same type */
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#if defined(SS_DEBUG)
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skygw_chk_t rses_prop_chk_tail;
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#endif
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};
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typedef struct sescmd_cursor_st {
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#if defined(SS_DEBUG)
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skygw_chk_t scmd_cur_chk_top;
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#endif
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ROUTER_CLIENT_SES* scmd_cur_rses; /*< pointer to owning router session */
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rses_property_t** scmd_cur_ptr_property; /*< address of pointer to owner property */
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mysql_sescmd_t* scmd_cur_cmd; /*< pointer to current session command */
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bool scmd_cur_active; /*< true if command is being executed */
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int position; /*< Position of this cursor */
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#if defined(SS_DEBUG)
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skygw_chk_t scmd_cur_chk_tail;
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#endif
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} sescmd_cursor_t;
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/**
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* Internal structure used to define the set of backend servers we are routing
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* connections to. This provides the storage for routing module specific data
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* that is required for each of the backend servers.
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*
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* Owned by router_instance, referenced by each routing session.
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*/
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typedef struct backend_st {
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#if defined(SS_DEBUG)
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skygw_chk_t be_chk_top;
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#endif
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SERVER* backend_server; /*< The server itself */
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int backend_conn_count; /*< Number of connections to
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* the server
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*/
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bool be_valid; /*< Valid when belongs to the
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* router's configuration
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*/
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int weight; /*< Desired weighting on the
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* load. Expressed in .1%
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* increments
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*/
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#if defined(SS_DEBUG)
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skygw_chk_t be_chk_tail;
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#endif
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} BACKEND;
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/**
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* Reference to BACKEND.
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*
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* Owned by router client session.
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*/
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typedef struct backend_ref_st {
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#if defined(SS_DEBUG)
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skygw_chk_t bref_chk_top;
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#endif
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BACKEND* bref_backend;
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DCB* bref_dcb;
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bref_state_t bref_state;
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int bref_num_result_wait;
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sescmd_cursor_t bref_sescmd_cur;
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GWBUF* bref_pending_cmd; /*< For stmt which can't be routed due active sescmd execution */
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unsigned char
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reply_cmd; /*< The reply the backend server sent to a session command.
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* Used to detect slaves that fail to execute session command. */
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#if defined(SS_DEBUG)
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skygw_chk_t bref_chk_tail;
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#endif
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} backend_ref_t;
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typedef struct rwsplit_config_st {
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int rw_max_slave_conn_percent;
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int rw_max_slave_conn_count;
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select_criteria_t rw_slave_select_criteria;
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int rw_max_slave_replication_lag;
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target_t rw_use_sql_variables_in;
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int rw_max_sescmd_history_size;
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bool disable_sescmd_hist;
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bool disable_slave_recovery;
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bool master_reads; /*< Use master for reads */
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} rwsplit_config_t;
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#if defined(PREP_STMT_CACHING)
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typedef struct prep_stmt_st {
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#if defined(SS_DEBUG)
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skygw_chk_t pstmt_chk_top;
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#endif
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union id {
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int seq;
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char* name;
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} pstmt_id;
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prep_stmt_state_t pstmt_state;
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prep_stmt_type_t pstmt_type;
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#if defined(SS_DEBUG)
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skygw_chk_t pstmt_chk_tail;
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#endif
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} prep_stmt_t;
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#endif /*< PREP_STMT_CACHING */
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/**
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* The client session structure used within this router.
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*/
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struct router_client_session {
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#if defined(SS_DEBUG)
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skygw_chk_t rses_chk_top;
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#endif
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SPINLOCK rses_lock; /*< protects rses_deleted */
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int rses_versno; /*< even = no active update, else odd. not used 4/14 */
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bool rses_closed; /*< true when closeSession is called */
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/** Properties listed by their type */
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rses_property_t* rses_properties[RSES_PROP_TYPE_COUNT];
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backend_ref_t* rses_master_ref;
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backend_ref_t* rses_backend_ref; /*< Pointer to backend reference array */
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rwsplit_config_t rses_config; /*< copied config info from router instance */
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int rses_nbackends;
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int rses_nsescmd; /*< Number of executed session commands */
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int rses_capabilities; /*< input type, for example */
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bool rses_autocommit_enabled;
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bool rses_transaction_active;
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DCB* client_dcb;
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int pos_generator;
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#if defined(PREP_STMT_CACHING)
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HASHTABLE* rses_prep_stmt[2];
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#endif
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struct router_instance *router; /*< The router instance */
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struct router_client_session* next;
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#if defined(SS_DEBUG)
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skygw_chk_t rses_chk_tail;
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#endif
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};
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/**
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* The statistics for this router instance
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*/
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typedef struct {
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int n_sessions; /*< Number sessions created */
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int n_queries; /*< Number of queries forwarded */
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int n_master; /*< Number of stmts sent to master */
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int n_slave; /*< Number of stmts sent to slave */
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int n_all; /*< Number of stmts sent to all */
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} ROUTER_STATS;
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/**
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* The per instance data for the router.
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*/
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typedef struct router_instance {
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SERVICE* service; /*< Pointer to service */
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ROUTER_CLIENT_SES* connections; /*< List of client connections */
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SPINLOCK lock; /*< Lock for the instance data */
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BACKEND** servers; /*< Backend servers */
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BACKEND* master; /*< NULL or pointer */
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rwsplit_config_t rwsplit_config; /*< expanded config info from SERVICE */
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int rwsplit_version;/*< version number for router's config */
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unsigned int bitmask; /*< Bitmask to apply to server->status */
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unsigned int bitvalue; /*< Required value of server->status */
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ROUTER_STATS stats; /*< Statistics for this router */
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struct router_instance* next; /*< Next router on the list */
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bool available_slaves;
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/*< The router has some slaves avialable */
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} ROUTER_INSTANCE;
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#define BACKEND_TYPE(b) (SERVER_IS_MASTER((b)->backend_server) ? BE_MASTER : \
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(SERVER_IS_SLAVE((b)->backend_server) ? BE_SLAVE : BE_UNDEFINED));
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#endif /*< _RWSPLITROUTER_H */
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