5bcae64538
Rwsplit handles ERRACT_NEW_CONNECTION by clearing backend reference, removing callbacks and associating backend reference with new backend server. If it succeeds and the router session can continue, handleError returns true. Otherwise false. When ever false is returned it means that session must be closed. Rwsplit now tolerates backend failures in a way that it searches new backends when monitor, backend, or client operation fails due to backend failure.
109 lines
3.6 KiB
C
109 lines
3.6 KiB
C
#ifndef _ROUTER_H
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#define _ROUTER_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 query router interface mechanisms
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*
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* Revision History
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*
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* Date Who Description
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* 14/06/2013 Mark Riddoch Initial implementation
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* 26/06/2013 Mark Riddoch Addition of router options
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* and the diagnostic entry point
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* 15/07/2013 Massimiliano Pinto Added clientReply entry point
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* 16/07/2013 Massimiliano Pinto Added router commands values
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* 22/10/2013 Massimiliano Pinto Added router errorReply entry point
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*
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*/
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#include <service.h>
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#include <session.h>
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#include <buffer.h>
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#include <stdint.h>
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/**
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* The ROUTER handle points to module specific data, so the best we can do
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* is to make it a void * externally.
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*/
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typedef void *ROUTER;
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/**
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* @verbatim
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* The "module object" structure for a query router module
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*
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* The entry points are:
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* createInstance Called by the service to create a new
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* instance of the query router
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* newSession Called to create a new user session
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* within the query router
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* closeSession Called when a session is closed
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* routeQuery Called on each query that requires
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* routing
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* diagnostics Called to force the router to print
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* diagnostic output
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* clientReply Called to reply to client the data from one or all backends
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* errorReply Called to reply to client errors with optional closeSession or
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* make a request for a new backend connection
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*
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* @endverbatim
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*
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* @see load_module
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*/
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typedef enum error_action {
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ERRACT_NEW_CONNECTION = 0x001,
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ERRACT_REPLY_CLIENT = 0x002
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} error_action_t;
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typedef struct router_object {
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ROUTER *(*createInstance)(SERVICE *service, char **options);
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void *(*newSession)(ROUTER *instance, SESSION *session);
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void (*closeSession)(ROUTER *instance, void *router_session);
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void (*freeSession)(ROUTER *instance, void *router_session);
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int (*routeQuery)(ROUTER *instance, void *router_session, GWBUF *queue);
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void (*diagnostics)(ROUTER *instance, DCB *dcb);
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void (*clientReply)(ROUTER* instance, void* router_session, GWBUF* queue, DCB *backend_dcb);
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void (*handleError)(
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ROUTER* instance,
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void* router_session,
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GWBUF* errmsgbuf,
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DCB* backend_dcb,
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error_action_t action,
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bool* succp);
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uint8_t (*getCapabilities)(ROUTER *instance, void* router_session);
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} ROUTER_OBJECT;
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/**
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* The router module API version. Any change that changes the router API
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* must update these versions numbers in accordance with the rules in
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* modinfo.h.
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*/
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#define ROUTER_VERSION { 1, 0, 0 }
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typedef enum router_capability_t {
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RCAP_TYPE_UNDEFINED = 0,
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RCAP_TYPE_STMT_INPUT = (1 << 0),
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RCAP_TYPE_PACKET_INPUT = (1 << 1)
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} router_capability_t;
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#endif
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