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Renamed router to readwritesplit

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This commit is contained in:
vraatikka
2013-07-10 11:30:58 +03:00
parent efb6e7b7aa
commit 7e1840b609
4 changed files with 569 additions and 206 deletions
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82
modules/include/readwritesplit.h Normal file
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@ -0,0 +1,82 @@
#ifndef _RWSPLITROUTER_H
#define _RWSPLITROUTER_H
/*
* This file is distributed as part of the SkySQL Gateway. 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 SkySQL Ab 2013
*/
/**
* @file router.h - The read write split router module heder file
*
* @verbatim
* Revision History
*
* Tässä mitään historioita..
*
* @endverbatim
*/
#include <dcb.h>
typedef struct client_session CLIENT_SESSION;
typedef struct instance INSTANCE;
/**
* Internal structure used to define the set of backend servers we are routing
* connections to. This provides the storage for routing module specific data
* that is required for each of the backend servers.
*/
typedef struct backend {
SERVER* server; /**< The server itself */
int count; /**< Number of connections to the server */
} BACKEND;
/**
* The client session structure used within this router.
*/
struct client_session {
BACKEND* slave; /**< Slave used by the client session */
BACKEND* master; /**< Master used by the client session */
DCB* slaveconn; /**< Slave connection */
DCB* masterconn; /**< Master connection */
CLIENT_SESSION* next;
};
/**
* The statistics for this router instance
*/
typedef struct {
int n_sessions; /**< Number sessions created */
int n_queries; /**< Number of queries forwarded */
} ROUTER_STATS;
/**
* The per instance data for the router.
*/
struct instance {
SERVICE* service; /**< Pointer to the service using this router */
CLIENT_SESSION* connections; /**< Link list of all the client connections */
SPINLOCK lock; /**< Spinlock for the instance data */
BACKEND** servers; /**< The set of backend servers for this instance */
BACKEND* master; /**< NULL if not known, pointer otherwise */
unsigned int bitmask; /**< Bitmask to apply to server->status */
unsigned int bitvalue;/**< Required value of server->status */
ROUTER_STATS stats; /**< Statistics for this router */
INSTANCE* next;
};
#endif

2
modules/routing/readwritesplit/Makefile
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@ -34,7 +34,7 @@ include ../../../../makefile.inc
LDFLAGS=-shared -L$(LOGPATH) -L$(QCLASSPATH) -L$(MARIADB_SRC_PATH)/libmysqld \ LDFLAGS=-shared -L$(LOGPATH) -L$(QCLASSPATH) -L$(MARIADB_SRC_PATH)/libmysqld \
-Wl,-rpath,$(LOGPATH) -Wl,-rpath,$(UTILSPATH) -Wl,-rpath,$(QCLASSPATH) \ -Wl,-rpath,$(LOGPATH) -Wl,-rpath,$(UTILSPATH) -Wl,-rpath,$(QCLASSPATH) \
-Wl,-rpath,$(MARIADB_SRC_PATH)/libmysqld -Wl,-rpath,$(MARIADB_SRC_PATH)/libmysqld
SRCS=router.c SRCS=readwritesplit.c
OBJ=$(SRCS:.c=.o) OBJ=$(SRCS:.c=.o)
LIBS=-lssl -pthread -llog_manager -lquery_classifier -lmysqld LIBS=-lssl -pthread -llog_manager -lquery_classifier -lmysqld
MODULES=libreadwritesplit.so MODULES=libreadwritesplit.so

486
modules/routing/readwritesplit/readwritesplit.c Normal file
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/*
* This file is distributed as part of the SkySQL Gateway. 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 SkySQL Ab 2013
*/
#include <stdio.h>
#include <strings.h>
#include <router.h>
#include <readwritesplit.h>
#include <stdlib.h>
#include <mysql.h>
#include <skygw_utils.h>
#include <log_manager.h>
#include <query_classifier.h>
#include <dcb.h>
#include <spinlock.h>
/**
* @file router.c The entry points for the read/write query splitting
* router module.
*
* This file contains the entry points that comprise the API to the read write
* query splitting router.
*
*/
static char *version_str = "V1.0.0";
static ROUTER* createInstance(SERVICE *service, char **options);
static void* newSession(ROUTER *instance, SESSION *session);
static void closeSession(ROUTER *instance, void *session);
static int routeQuery(ROUTER *instance, void *session, GWBUF *queue);
static void diagnostic(ROUTER *instance, DCB *dcb);
static ROUTER_OBJECT MyObject =
{ createInstance,
newSession,
closeSession,
routeQuery,
diagnostic };
static SPINLOCK instlock;
static INSTANCE* instances;
#if defined(SS_DEBUG)
static void vilhos_test_for_query_classifier(void)
{
MYSQL* mysql = NULL;
ss_dassert(mysql_thread_safe());
mysql_thread_init();
char* str = (char *)calloc(1,
sizeof("Query type is ")+
sizeof("QUERY_TYPE_SESSION_WRITE"));
/**
* Call query classifier.
*/
sprintf(str,
"Query type is %s\n",
STRQTYPE(
skygw_query_classifier_get_type(
"SELECT user from mysql.user", 0)));
/**
* generate some log
*/
skygw_log_write(NULL, LOGFILE_MESSAGE,str);
mysql_close(mysql);
mysql_thread_end();
ss_dfprintf(stderr, "\n<< testmain\n");
fflush(stderr);
}
#endif /* SS_DEBUG */
/**
* Implementation of the mandatory version entry point
*
* @return version string of the module
*/
char *
version()
{
return version_str;
}
/**
* The module initialisation routine, called when the module
* is first loaded.
*/
void
ModuleInit()
{
skygw_log_write_flush(NULL,
LOGFILE_MESSAGE,
"Initialize read/write split router module.\n");
spinlock_init(&instlock);
instances = NULL;
#if defined(NOMORE)
vilhos_test_for_query_classifier();
#endif
}
/**
* The module entry point routine. It is this routine that
* must populate the structure that is referred to as the
* "module object", this is a structure with the set of
* external entry points for this module.
*
* @return The module object
*/
ROUTER_OBJECT* GetModuleObject() {
skygw_log_write(NULL,
LOGFILE_TRACE,
"Returning readwritesplit router module object.");
return &MyObject;
}
/**
* Create an instance of the router for a particular service
* within the gateway.
*
* The job of ths entry point is to create the service wide data needed
* for the query router. This is information needed to route queries that
* is not related to any individual client session, exmaples of data that
* might be stored in the ROUTER object for a particular query router are
* connections counts, last used connection etc so that balancing may
* take place.
*
* @param service The service this router is being create for
* @param options The options for this query router
*
* @return The instance data for this new instance
*/
static ROUTER* createInstance(
SERVICE* service,
char** options)
{
INSTANCE* inst;
SERVER* server;
int n;
int i;
if ((inst = calloc(1, sizeof(INSTANCE))) == NULL) {
return NULL;
}
inst->service = service;
spinlock_init(&inst->lock);
inst->connections = NULL;
/** Calculate number of servers */
for (server = service->databases, n = 0; server; server = server->nextdb) {
n++;
}
inst->servers = (BACKEND **)calloc(n + 1, sizeof(BACKEND *));
if (!inst->servers) {
free(inst);
return NULL;
}
/**
* We need an array of the backend servers in the instance structure so
* that we can maintain a count of the number of connections to each
* backend server.
*/
for (server = service->databases, n = 0; server; server = server->nextdb) {
if ((inst->servers[n] = malloc(sizeof(BACKEND))) == NULL) {
for (i = 0; i < n; i++) {
free(inst->servers[i]);
}
free(inst->servers);
free(inst);
return NULL;
}
inst->servers[n]->server = server;
inst->servers[n]->count = 0;
n++;
}
inst->servers[n] = NULL;
/*
* Process the options
*/
inst->bitmask = 0;
inst->bitvalue = 0;
if (options) {
for (i = 0; options[i]; i++) {
if (!strcasecmp(options[i], "master")) {
inst->bitmask |= SERVER_MASTER;
inst->bitvalue |= SERVER_MASTER;
ss_dassert(inst->master == NULL);
inst->master = inst->servers[i];
} else if (!strcasecmp(options[i], "slave")) {
inst->bitmask |= SERVER_MASTER;
inst->bitvalue &= ~SERVER_MASTER;
}
} /* for */
}
/**
* We have completed the creation of the instance data, so now
* insert this router instance into the linked list of routers
* that have been created with this module.
*/
spinlock_acquire(&instlock);
inst->next = instances;
instances = inst;
spinlock_release(&instlock);
return (ROUTER *)inst;
}
/**
* Associate a new session with this instance of the router.
*
* The session is used to store all the data required for a particular
* client connection.
*
* @param instance The router instance data
* @param session The session itself
* @return Session specific data for this session
*/
static void* newSession(
ROUTER* instance,
SESSION* session)
{
BACKEND* candidate = NULL;
CLIENT_SESSION* client;
INSTANCE* inst = (INSTANCE *)instance;
int i;
if ((client = (CLIENT_SESSION *)malloc(sizeof(CLIENT_SESSION))) == NULL) {
return NULL;
}
/**
* Find a backend server to connect to. This is the extent of the
* load balancing algorithm we need to implement for this simple
* connection router.
*/
/** First find a running server to set as our initial candidate server */
for (i = 0; inst->servers[i]; i++) {
if (inst->servers[i] && SERVER_IS_RUNNING(inst->servers[i]->server) &&
(inst->servers[i]->server->status & inst->bitmask) == inst->bitvalue)
{
candidate = inst->servers[i];
break;
}
}
/**
* Loop over all the servers and find any that have fewer connections than our
* candidate server.
*
* If a server has less connections than the current candidate we mark this
* as the new candidate to connect to.
*
* If a server has the same number of connections currently as the candidate
* and has had less connections over time than the candidate it will also
* become the new candidate. This has the effect of spreading the connections
* over different servers during periods of very low load.
*/
for (i = 1; inst->servers[i]; i++) {
if (inst->servers[i]
&& SERVER_IS_RUNNING(inst->servers[i]->server))
{
if ((inst->servers[i]->server->status & inst->bitmask)
== inst->bitvalue)
{
if (inst->servers[i]->count < candidate->count) {
candidate = inst->servers[i];
} else if (inst->servers[i]->count == candidate->count &&
inst->servers[i]->server->stats.n_connections
< candidate->server->stats.n_connections)
{
candidate = inst->servers[i];
}
} else if (SERVER_IS_MASTER(inst->servers[i]->server)) {
/** master is found */
inst->master = inst->servers[i];
}
}
} /* for */
if (inst->master == NULL) {
inst->master = inst->servers[i-1];
}
/**
* We now have a master and a slave server with the least connections.
* Bump the connection counts for these servers.
*/
atomic_add(&candidate->count, 1);
client->slave = candidate;
atomic_add(&inst->master->count, 1);
client->master = inst->master;
ss_dassert(client->master->server != candidate->server);
/**
* Open the slave connection.
*/
if ((client->slaveconn = dcb_connect(candidate->server,
session,
candidate->server->protocol)) == NULL)
{
atomic_add(&candidate->count, -1);
free(client);
return NULL;
}
/**
* Open the master connection.
*/
if ((client->masterconn =
dcb_connect(client->master->server,
session,
client->master->server->protocol)) == NULL)
{
atomic_add(&client->master->count, -1);
free(client);
return NULL;
}
inst->stats.n_sessions += 1;
/* Add this session to end of the list of active sessions */
spinlock_acquire(&inst->lock);
client->next = inst->connections;
inst->connections = client;
spinlock_release(&inst->lock);
return (void *)client;
}
/**
* Close a session with the router, this is the mechanism
* by which a router may cleanup data structure etc.
*
* @param instance The router instance data
* @param session The session being closed
*/
static void
closeSession(ROUTER *instance, void *session)
{
}
/**
* The main routing entry, this is called with every packet that is
* received and has to be forwarded to the backend database.
*
* The routeQuery will make the routing decision based on the contents
* of the instance, session and the query itself in the queue. The
* data in the queue may not represent a complete query, it represents
* the data that has been received. The query router itself is responsible
* for buffering the partial query, a later call to the query router will
* contain the remainder, or part thereof of the query.
*
* @param instance The query router instance
* @param session The session associated with the client
* @param queue Gateway buffer queue with the packets received
*
* @return The number of queries forwarded
*/
static int routeQuery(
ROUTER* instance,
void* router_session,
GWBUF* queue)
{
skygw_query_type_t qtype = QUERY_TYPE_UNKNOWN;
char* startpos;
char* querystr;
size_t len;
unsigned char packet_type;
INSTANCE* inst = (INSTANCE *)instance;
CLIENT_SESSION* session = (CLIENT_SESSION *)router_session;
inst->stats.n_queries++;
packet_type = (unsigned char)queue->data[4];
startpos = (char *)&queue->data[5];
len = (unsigned char)queue->data[0];
len += 255*(unsigned char)queue->data[1];
len += 255*255*((unsigned char)queue->data[2]);
querystr = (char *)malloc(len);
snprintf(querystr, len, "%s", startpos);
skygw_log_write(NULL,
LOGFILE_TRACE,
"Packet type %s. %s : %d.",
STRPACKETTYPE(packet_type),
__FILE__,
__LINE__);
switch(packet_type) {
case COM_INIT_DB: /**< 2 */
case COM_CREATE_DB: /**< 5 */
case COM_DROP_DB: /**< 6 */
case COM_REFRESH: /**< 7 - I guess this is session but not sure */
case COM_DEBUG: /**< 0d all servers dump debug info to stdout */
case COM_PING: /**< 0e all servers are pinged */
case COM_CHANGE_USER: /**< 11 all servers change it accordingly */
qtype = QUERY_TYPE_SESSION_WRITE;
break;
case COM_QUERY:
qtype = skygw_query_classifier_get_type(querystr, 0);
break;
default:
case COM_SHUTDOWN: /**< 8 where shutdown soulh be routed ? */
case COM_STATISTICS: /**< 9 ? */
case COM_PROCESS_INFO: /**< 0a ? */
case COM_CONNECT: /**< 0b ? */
case COM_PROCESS_KILL: /**< 0c ? */
case COM_TIME: /**< 0f should this be run in gateway ? */
case COM_DELAYED_INSERT: /**< 10 ? */
case COM_DAEMON: /**< 1d ? */
break;
}
switch (qtype) {
case QUERY_TYPE_WRITE:
skygw_log_write(NULL,
LOGFILE_MESSAGE,
"Query type : %s, routing to Master.",
STRQTYPE(qtype));
return session->masterconn->func.write(session->masterconn, queue);
break;
case QUERY_TYPE_READ:
skygw_log_write(NULL,
LOGFILE_MESSAGE,
"Query type : %s, routing to Slave.",
STRQTYPE(qtype));
return session->slaveconn->func.write(session->slaveconn, queue);
break;
case QUERY_TYPE_SESSION_WRITE:
skygw_log_write(NULL,
LOGFILE_MESSAGE,
"Query type : %s, routing to Master.",
STRQTYPE(qtype));
/**
* TODO! Connection to all servers must be established, and
* the command must be executed in them.
*/
return session->masterconn->func.write(session->masterconn, queue);
break;
default:
skygw_log_write(NULL,
LOGFILE_MESSAGE,
"Query type : %s, routing to Master.",
STRQTYPE(qtype));
/** Is this really ok? */
return session->masterconn->func.write(session->masterconn, queue);
break;
}
return 0;
}
/**
* Diagnostics routine
*
* Print query router statistics to the DCB passed in
*
* @param instance The router instance
* @param dcb The DCB for diagnostic output
*/
static void
diagnostic(ROUTER *instance, DCB *dcb)
{
}

205
modules/routing/readwritesplit/router.c
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@ -1,205 +0,0 @@
/*
* This file is distributed as part of the SkySQL Gateway. 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 SkySQL Ab 2013
*/
#include <stdio.h>
#include <router.h>
# include <stdlib.h>
# include <mysql.h>
# include <skygw_utils.h>
# include <log_manager.h>
# include <query_classifier.h>
/**
* @file router.c The entry points for the read/write query splitting
* router module.
*
* This file contains the entry points that comprise the API to the read write
* query splitting router.
*
*/
static char *version_str = "V1.0.0";
static ROUTER *createInstance(SERVICE *service, char **options);
static void *newSession(ROUTER *instance, SESSION *session);
static void closeSession(ROUTER *instance, void *session);
static int routeQuery(ROUTER *instance, void *session, GWBUF *queue);
static void diagnostic(ROUTER *instance, DCB *dcb);
static ROUTER_OBJECT MyObject = { createInstance, newSession, closeSession, routeQuery, diagnostic };
#if defined(SS_DEBUG)
static void vilhos_test_for_query_classifier(void)
{
bool failp;
MYSQL* mysql = NULL;
ss_dassert(mysql_thread_safe());
mysql_thread_init();
char* str = (char *)calloc(1,
sizeof("Query type is ")+
sizeof("QUERY_TYPE_SESSION_WRITE"));
/**
* Call query classifier.
*/
sprintf(str,
"Query type is %s\n",
STRQTYPE(
skygw_query_classifier_get_type(
"SELECT user from mysql.user", 0)));
/**
* generate some log
*/
skygw_log_write(NULL, LOGFILE_MESSAGE,str);
mysql_close(mysql);
mysql_thread_end();
return_without_server:
ss_dfprintf(stderr, "\n<< testmain\n");
fflush(stderr);
}
#endif /* SS_DEBUG */
/**
* Implementation of the mandatory version entry point
*
* @return version string of the module
*/
char *
version()
{
return version_str;
}
/**
* The module initialisation routine, called when the module
* is first loaded.
*/
void
ModuleInit()
{
// rename_libfuncs();
#if defined(SS_DEBUG)
vilhos_test_for_query_classifier();
#endif
fprintf(stderr, "Initialse read/writer splitting query router module.\n");
}
/**
* The module entry point routine. It is this routine that
* must populate the structure that is referred to as the
* "module object", this is a structure with the set of
* external entry points for this module.
*
* @return The module object
*/
ROUTER_OBJECT *
GetModuleObject()
{
fprintf(stderr, "Returing test router module object.\n");
return &MyObject;
}
/**
* Create an instance of the router for a particular service
* within the gateway.
*
* The job of ths entry point is to create the service wide data needed
* for the query router. This is information needed to route queries that
* is not related to any individual client session, exmaples of data that
* might be stored in the ROUTER object for a particular query router are
* connections counts, last used connection etc so that balancing may
* take place.
*
* @param service The service this router is being create for
* @param options The options for this query router
*
* @return The instance data for this new instance
*/
static ROUTER *
createInstance(SERVICE *service, char **options)
{
return NULL;
}
/**
* Associate a new session with this instance of the router.
*
* The session is used to store all the data required for a particular
* client connection.
*
* @param instance The router instance data
* @param session The session itself
* @return Session specific data for this session
*/
static void *
newSession(ROUTER *instance, SESSION *session)
{
return NULL;
}
/**
* Close a session with the router, this is the mechanism
* by which a router may cleanup data structure etc.
*
* @param instance The router instance data
* @param session The session being closed
*/
static void
closeSession(ROUTER *instance, void *session)
{
}
/**
* The main routing entry, this is called with every packet that is
* received and has to be forwarded to the backend database.
*
* The routeQuery will make the routing decision based on the contents
* of the instance, session and the query itself in the queue. The
* data in the queue may not represent a complete query, it represents
* the data that has been received. The query router itself is responsible
* for buffering the partial query, a later call to the query router will
* contain the remainder, or part thereof of the query.
*
* @param instance The query router instance
* @param session The session assoicated with the client
* @param queue Gateway buffer queue with the packets received
*
* @return The number of queries forwarded
*/
static int
routeQuery(ROUTER *instance, void *session, GWBUF *queue)
{
return 0;
}
/**
* Diagnostics routine
*
* Print query router statistics to the DCB passed in
*
* @param instance The router instance
* @param dcb The DCB for diagnostic output
*/
static void
diagnostic(ROUTER *instance, DCB *dcb)
{
}