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Merge branch 'MAX-324' of https://github.com/mariadb-corporation/MaxScale into MAX-324

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Conflicts:
	server/modules/include/dbshard.h
	server/modules/routing/dbshard/dbshard.c
This commit is contained in:
VilhoRaatikka
2014-12-01 19:34:20 +02:00
parent dd600d025a 66164aa664
commit ef4f9aac4f
3 changed files with 237 additions and 10 deletions
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28
server/modules/include/dbshard.h
View File

@ -1,5 +1,28 @@
#ifndef _DBSHARDROUTER_H
#define _DBSHARDROUTER_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 router.h - The dbshard router module heder file
*
* @verbatim
* Revision History
*
* See GitHub https://github.com/skysql/MaxScale
*
@ -293,9 +316,14 @@ typedef struct router_instance {
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 */
HASHTABLE* dbnames_hash; /** Hashtable containing the database names and where to find them */
} ROUTER_INSTANCE;
#define BACKEND_TYPE(b) (SERVER_IS_MASTER((b)->backend_server) ? BE_MASTER : \
(SERVER_IS_SLAVE((b)->backend_server) ? BE_SLAVE : BE_UNDEFINED));
void* dbnames_hash_init(BACKEND** backends);
bool update_dbnames_hash(BACKEND** backends, HASHTABLE* hashtable);
#endif /*< _DBSHARDROUTER_H */

4
server/modules/routing/CMakeLists.txt
View File

@ -6,6 +6,10 @@ add_library(testroute SHARED testroute.c)
target_link_libraries(testroute log_manager utils)
install(TARGETS testroute DESTINATION modules)
add_library(dbshard SHARED dbshard/dbshard.c)
target_link_libraries(dbshard log_manager utils query_classifier)
install(TARGETS dbshard DESTINATION modules)
add_library(readconnroute SHARED readconnroute.c)
target_link_libraries(readconnroute log_manager utils)
install(TARGETS readconnroute DESTINATION modules)

215
server/modules/routing/dbshard/dbshard.c
View File

@ -233,6 +233,11 @@ static void tracelog_routed_query(
backend_ref_t* bref,
GWBUF* buf);
static void dbshard_process_router_options(
ROUTER_INSTANCE* router,
char** options);
static bool route_session_write(
ROUTER_CLIENT_SES* router_client_ses,
GWBUF* querybuf,
@ -311,6 +316,153 @@ static void* hfree(void* fval)
}
/**
* Updates the hashtable with the database names and where to find them, adding new and removing obsolete pairs.
* @param backends Backends to query for database names
* @param hashtable Hashtable to use
* @return True if all database and server names were successfully retrieved otherwise false
*/
bool update_dbnames_hash(BACKEND** backends, HASHTABLE* hashtable)
{
const unsigned int connect_timeout = 5;
const unsigned int read_timeout = 2;
bool rval = true;
SERVER* server;
MYSQL* handle;
MYSQL_RES* result;
MYSQL_ROW row;
int i, rc, numfields;
for(i = 0;backends[i] && rval;i++){
handle = mysql_init(NULL);
if(handle == NULL){
LOGIF(LE, (skygw_log_write_flush(LOGFILE_ERROR,"Error: Failed to initialize MySQL handle.")));
continue;
}
rc = 0;
rc |= mysql_options(handle, MYSQL_OPT_CONNECT_TIMEOUT, (void *)&connect_timeout);
rc |= mysql_options(handle, MYSQL_OPT_READ_TIMEOUT, (void *)&read_timeout);
if(rc != 0){
LOGIF(LE, (skygw_log_write_flush(LOGFILE_ERROR,"Error: Failed to set MySQL connection options.")));
mysql_close(handle);
rval = false;
continue;
}
server = backends[i]->backend_server;
ss_dassert(server != NULL);
if (mysql_real_connect(handle,
server->name,
server->monuser,
server->monpw,
NULL,
server->port,
NULL,
0) == NULL)
{
LOGIF(LE, (skygw_log_write_flush(
LOGFILE_ERROR,
"Error: Failed to connect to backend server '%s'.",server->name)));
rval = false;
goto cleanup;
}
/**
* The server was successfully connected to, proceed to query for database names
*/
if((result = mysql_list_dbs(handle,NULL)) == NULL){
LOGIF(LE, (skygw_log_write_flush(LOGFILE_ERROR,
"Error: Failed to execute query in backend server '%s'.",server->name)));
goto cleanup;
}
numfields = mysql_num_fields(result);
if(numfields < 1){
LOGIF(LT, (skygw_log_write_flush(LOGFILE_TRACE,
"Backend '%s' has no databases.",server->name)));
goto cleanup;
}
/**
* Walk through the list of databases in this backend
* and insert them into the hashtable. If the value is already in the hashtable
* but the backend isn't in the list of backends it is replaced with the first found backend.
*/
while((row = mysql_fetch_row(result)))
{
unsigned long *lengths;
char *dbnm = NULL,*servnm = NULL;
lengths = mysql_fetch_lengths(result);
dbnm = (char*)calloc(lengths[0] + 1,sizeof(char));
memcpy(dbnm,row[0],lengths[0]);
servnm = strdup(server->unique_name);
if(hashtable_add(hashtable,dbnm,servnm) == 0){
/*Check if the failure was due to a duplicate value*/
if(hashtable_fetch(hashtable,dbnm) == NULL){
LOGIF(LE, (skygw_log_write_flush(LOGFILE_ERROR,
"Error: Failed to insert values into hashtable.")));
}else{
LOGIF(LE, (skygw_log_write_flush(LOGFILE_ERROR,
"Error: Duplicate value found.")));
}
rval = false;
free(dbnm);
free(servnm);
}
}
cleanup:
if(result){
mysql_free_result(result);
}
result = NULL;
mysql_close(handle);
}
return rval;
}
/**
* Allocates a new hashtable and inserts database names and where to find them into it.
* @param backends Backends to query for database names
* @return Pointer to the newly allocated hashtable or NULL if an error occurred
*/
void* dbnames_hash_init(BACKEND** backends)
{
HASHTABLE* htbl = hashtable_alloc(32,hashkeyfun,hashcmpfun);
if(htbl == NULL)
{
LOGIF(LE, (skygw_log_write_flush(LOGFILE_ERROR,"Error: Hashtable allocation failed.")));
return NULL;
}
/**Update the new hashtable with the key-value pairs*/
if(!update_dbnames_hash(backends,htbl)){
LOGIF(LE, (skygw_log_write_flush(LOGFILE_ERROR,"Errors encountered while querying databases.")));
hashtable_free(htbl);
return NULL;
}
return htbl;
}
/**
* Implementation of the mandatory version entry point
*
@ -574,11 +726,11 @@ createInstance(SERVICE *service, char **options)
* is used if any.
*/
router->dbshard_version = service->svc_config_version;
refreshInstance(router, NULL);
/**
* Get hashtable which includes dbname,backend pairs
*/
router->dbnames_hash = dbnames_hash_init(router->servers);
router->dbnames_hash = (HASHTABLE*)dbnames_hash_init(router->servers);
/**
* We have completed the creation of the router data, so now
* insert this router into the linked list of routers
@ -4252,11 +4404,54 @@ static backend_ref_t* get_root_master_bref(
}
static void dbshard_process_router_options(
ROUTER_INSTANCE* router,
char** options)
{
int i;
char* value;
select_criteria_t c;
for (i = 0; options[i]; i++)
{
if ((value = strchr(options[i], '=')) == NULL)
{
LOGIF(LE, (skygw_log_write(
LOGFILE_ERROR, "Warning : Unsupported "
"router option \"%s\" for "
"readwritesplit router.",
options[i])));
}
else
{
*value = 0;
value++;
if (strcmp(options[i], "slave_selection_criteria") == 0)
{
c = GET_SELECT_CRITERIA(value);
ss_dassert(
c == LEAST_GLOBAL_CONNECTIONS ||
c == LEAST_ROUTER_CONNECTIONS ||
c == LEAST_BEHIND_MASTER ||
c == LEAST_CURRENT_OPERATIONS ||
c == UNDEFINED_CRITERIA);
if (c == UNDEFINED_CRITERIA)
{
LOGIF(LE, (skygw_log_write(
LOGFILE_ERROR, "Warning : Unknown "
"slave selection criteria \"%s\". "
"Allowed values are LEAST_GLOBAL_CONNECTIONS, "
"LEAST_ROUTER_CONNECTIONS, "
"LEAST_BEHIND_MASTER,"
"and LEAST_CURRENT_OPERATIONS.",
STRCRITERIA(router->rwsplit_config.rw_slave_select_criteria))));
}
else
{
router->rwsplit_config.rw_slave_select_criteria = c;
}
}
}
} /*< for */
}