96f76a1f2e
Before these changes when max_sescmd_history was used the session was closed when the limit was exceeded. With this change, when the limit is exceeded the recovery of slaves and the session command history are both disabled. This will allow the sessions to continue while still keeping the old functionality of limited salve replacement. The disable_sescmd_history and disable_slave_recovery parameters were combined so that disabling the session command history will also disable slave recovery. This way no harm can be done with disable_sescmd_history.
344 lines
12 KiB
C
344 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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{
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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 rw_disable_sescmd_hist;
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bool rw_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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