a3f7eebdc9
This implementation doesn't guarantee execution order between session commands and queries if other backend server lags behind in session command execution. In poll.c : moved processing of EPOLLERR and EPOLLHUP after processing of EPOLLIN and EPOLLOUT. This ensures that COM_QUIT messages are read and routed forward before signals arrive (from local client/backend).
158 lines
5.6 KiB
C
158 lines
5.6 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 SkySQL Gateway. 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 SkySQL Ab 2013
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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/skysql/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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/**
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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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typedef struct backend {
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SERVER* backend_server; /*< The server itself */
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int backend_conn_count; /*< Number of connections to the server */
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} BACKEND;
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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=0,
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RSES_PROP_TYPE_SESCMD,
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RSES_PROP_TYPE_FIRST = RSES_PROP_TYPE_SESCMD,
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RSES_PROP_TYPE_LAST=RSES_PROP_TYPE_SESCMD,
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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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typedef enum backend_type_t {
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BE_UNDEFINED=-1,
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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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/**
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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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#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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void* placeholder; /*< to be removed due new type */
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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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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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backend_type_t scmd_cur_be_type; /*< BE_MASTER or BE_SLAVE */
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} sescmd_cursor_t;
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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 */
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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* rses_backend[BE_COUNT];/*< Backends used by client session */
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DCB* rses_dcb[BE_COUNT];
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/*< cursor is pointer and status variable to current session command */
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sescmd_cursor_t rses_cursor[BE_COUNT];
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int rses_capabilities; /*< input type, for example */
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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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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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} ROUTER_INSTANCE;
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#endif /*< _RWSPLITROUTER_H */
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