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Fix candidate for #645, http://bugs.skysql.com/show_bug.cgi?id=645 and #648, http://bugs.skysql.com/show_bug.cgi?id=648

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If readwritesplit.c:routeQuery gets a GWBUF whose type is UNDEFINED, then each MySQL packet is extracted from input buffer and passed to new function, route_single_stmt. Each extracted packet is stored in separate GWBUF and added types GWBUF_TYPE_MYSQL and GWBUG_TYPE_SINGLE_STMT which makes it possible to execute session commands and process reply packets properly.

Code nedes still cleaning but this is for testing atm.
This commit is contained in:
VilhoRaatikka
2014-12-13 01:55:40 +02:00
parent 339f604d73
commit c31f971999
3 changed files with 599 additions and 22 deletions
Download Patch File Download Diff File Expand all files Collapse all files

69
server/core/modutil.c
View File

@ -390,3 +390,72 @@ int modutil_send_mysql_err_packet (
return dcb->func.write(dcb, buf);
}
/**
* Buffer contains at least one of the following:
* complete [complete] [partial] mysql packet
*
* return pointer to gwbuf containing a complete packet or
* NULL if no complete packet was found.
*/
GWBUF* modutil_get_next_MySQL_packet(
GWBUF** p_readbuf)
{
GWBUF* packetbuf;
GWBUF* readbuf;
size_t buflen;
size_t packetlen;
size_t totalbuflen;
uint8_t* data;
size_t nbytes_copied = 0;
uint8_t* target;
readbuf = *p_readbuf;
if (readbuf == NULL)
{
packetbuf = NULL;
goto return_packetbuf;
}
CHK_GWBUF(readbuf);
if (GWBUF_EMPTY(readbuf))
{
packetbuf = NULL;
goto return_packetbuf;
}
totalbuflen = gwbuf_length(readbuf);
data = (uint8_t *)GWBUF_DATA((readbuf));
packetlen = MYSQL_GET_PACKET_LEN(data)+4;
/** packet is incomplete */
if (packetlen > totalbuflen)
{
packetbuf = NULL;
goto return_packetbuf;
}
packetbuf = gwbuf_alloc(packetlen);
target = GWBUF_DATA(packetbuf);
packetbuf->gwbuf_type = readbuf->gwbuf_type; /*< Copy the type too */
/**
* Copy first MySQL packet to packetbuf and leave posible other
* packets to read buffer.
*/
while (nbytes_copied < packetlen && totalbuflen > 0)
{
uint8_t* src = GWBUF_DATA((*p_readbuf));
size_t bytestocopy;
buflen = GWBUF_LENGTH((*p_readbuf));
bytestocopy = MIN(buflen,packetlen-nbytes_copied);
memcpy(target+nbytes_copied, src, bytestocopy);
*p_readbuf = gwbuf_consume((*p_readbuf), bytestocopy);
totalbuflen = gwbuf_length((*p_readbuf));
nbytes_copied += bytestocopy;
}
ss_dassert(buflen == 0 || nbytes_copied == packetlen);
return_packetbuf:
return packetbuf;
}

1
server/include/modutil.h
View File

@ -41,6 +41,7 @@ extern char *modutil_get_SQL(GWBUF *);
extern GWBUF *modutil_replace_SQL(GWBUF *, char *);
extern char *modutil_get_query(GWBUF* buf);
extern int modutil_send_mysql_err_packet(DCB *, int, int, int, const char *, const char *);
GWBUF* modutil_get_next_MySQL_packet(GWBUF** p_readbuf);
GWBUF *modutil_create_mysql_err_msg(
int packet_number,

551
server/modules/routing/readwritesplit/readwritesplit.c
View File

@ -111,6 +111,21 @@ static backend_ref_t* check_candidate_bref(
backend_ref_t* new_bref,
select_criteria_t sc);
static skygw_query_type_t is_read_tmp_table(
ROUTER_CLIENT_SES* router_cli_ses,
GWBUF* querybuf,
skygw_query_type_t type);
static void check_create_tmp_table(
ROUTER_CLIENT_SES* router_cli_ses,
GWBUF* querybuf,
skygw_query_type_t type);
static bool route_single_stmt(
ROUTER_INSTANCE* inst,
ROUTER_CLIENT_SES* rses,
GWBUF* querybuf);
static uint8_t getCapabilities (ROUTER* inst, void* router_session);
@ -1505,14 +1520,12 @@ static route_target_t get_route_target (
/**
* Check if the query is a DROP TABLE... query and
* if it targets a temporary table, remove it from the hashtable.
* @param instance Router instance
* @param router_session Router client session
* @param router_cli_ses Router client session
* @param querybuf GWBUF containing the query
* @param type The type of the query resolved so far
*/
void check_drop_tmp_table(
ROUTER* instance,
void* router_session,
ROUTER_CLIENT_SES* router_cli_ses,
GWBUF* querybuf,
skygw_query_type_t type)
{
@ -1522,7 +1535,6 @@ void check_drop_tmp_table(
char *hkey,*dbname;
MYSQL_session* data;
ROUTER_CLIENT_SES* router_cli_ses = (ROUTER_CLIENT_SES *)router_session;
DCB* master_dcb = NULL;
rses_property_t* rses_prop_tmp;
@ -1567,16 +1579,14 @@ void check_drop_tmp_table(
/**
* Check if the query targets a temporary table.
* @param instance Router instance
* @param router_session Router client session
* @param router_cli_ses Router client session
* @param querybuf GWBUF containing the query
* @param type The type of the query resolved so far
* @return The type of the query
*/
skygw_query_type_t is_read_tmp_table(
ROUTER* instance,
void* router_session,
GWBUF* querybuf,
static skygw_query_type_t is_read_tmp_table(
ROUTER_CLIENT_SES* router_cli_ses,
GWBUF* querybuf,
skygw_query_type_t type)
{
@ -1586,7 +1596,6 @@ skygw_query_type_t is_read_tmp_table(
char *hkey,*dbname;
MYSQL_session* data;
ROUTER_CLIENT_SES* router_cli_ses = (ROUTER_CLIENT_SES *)router_session;
DCB* master_dcb = NULL;
skygw_query_type_t qtype = type;
rses_property_t* rses_prop_tmp;
@ -1656,14 +1665,12 @@ skygw_query_type_t is_read_tmp_table(
* the database and table name, create a hashvalue and
* add it to the router client session's property. If property
* doesn't exist then create it first.
* @param instance Router instance
* @param router_session Router client session
* @param router_cli_ses Router client session
* @param querybuf GWBUF containing the query
* @param type The type of the query resolved so far
*/
void check_create_tmp_table(
ROUTER* instance,
void* router_session,
static void check_create_tmp_table(
ROUTER_CLIENT_SES* router_cli_ses,
GWBUF* querybuf,
skygw_query_type_t type)
{
@ -1673,7 +1680,6 @@ void check_create_tmp_table(
char *hkey,*dbname;
MYSQL_session* data;
ROUTER_CLIENT_SES* router_cli_ses = (ROUTER_CLIENT_SES *)router_session;
DCB* master_dcb = NULL;
rses_property_t* rses_prop_tmp;
HASHTABLE* h;
@ -1822,8 +1828,37 @@ static int routeQuery(
{
rses_is_closed = true;
}
#if 1
if (GWBUF_IS_TYPE_UNDEFINED(querybuf))
{
GWBUF* tmpbuf = querybuf;
do
{
if ((querybuf = modutil_get_next_MySQL_packet(&tmpbuf)) == NULL)
{
ret = 1;
goto retblock;
}
/** Mark buffer to as MySQL type */
gwbuf_set_type(querybuf, GWBUF_TYPE_MYSQL);
gwbuf_set_type(querybuf, GWBUF_TYPE_SINGLE_STMT);
succp = route_single_stmt(inst, router_cli_ses, querybuf);
}
while (tmpbuf != NULL && succp);
}
else
{
succp = route_single_stmt(inst, router_cli_ses, querybuf);
}
if (succp)
{
ret = 1;
}
goto retblock;
#else
ss_dassert(!GWBUF_IS_TYPE_UNDEFINED(querybuf));
packet = GWBUF_DATA(querybuf);
packet_type = packet[4];
@ -1925,9 +1960,9 @@ static int routeQuery(
/**
* Check if the query has anything to do with temporary tables.
*/
qtype = is_read_tmp_table(instance,router_session,querybuf,qtype);
check_create_tmp_table(instance,router_session,querybuf,qtype);
check_drop_tmp_table(instance,router_session,querybuf,qtype);
qtype = is_read_tmp_table(inst,router_cli_ses,querybuf,qtype);
check_create_tmp_table(inst,router_cli_ses,querybuf,qtype);
check_drop_tmp_table(inst,router_cli_ses,querybuf,qtype);
/**
* If autocommit is disabled or transaction is explicitly started
@ -2263,6 +2298,7 @@ static int routeQuery(
}
}
rses_end_locked_router_action(router_cli_ses);
#endif
retblock:
#if defined(SS_DEBUG2)
{
@ -2284,6 +2320,477 @@ retblock:
return ret;
}
static bool route_single_stmt(
ROUTER_INSTANCE* inst,
ROUTER_CLIENT_SES* rses,
GWBUF* querybuf)
{
skygw_query_type_t qtype = QUERY_TYPE_UNKNOWN;
mysql_server_cmd_t packet_type;
uint8_t* packet;
int ret = 0;
DCB* master_dcb = NULL;
DCB* target_dcb = NULL;
bool rses_is_closed = false;
route_target_t route_target;
bool succp;
int rlag_max = MAX_RLAG_UNDEFINED;
backend_type_t btype; /*< target backend type */
ss_dassert(!GWBUF_IS_TYPE_UNDEFINED(querybuf));
packet = GWBUF_DATA(querybuf);
packet_type = packet[4];
if (rses_is_closed)
{
/**
* MYSQL_COM_QUIT may have sent by client and as a part of backend
* closing procedure.
*/
if (packet_type != MYSQL_COM_QUIT)
{
char* query_str = modutil_get_query(querybuf);
LOGIF(LE,
(skygw_log_write_flush(
LOGFILE_ERROR,
"Error: Can't route %s:%s:\"%s\" to "
"backend server. Router is closed.",
STRPACKETTYPE(packet_type),
STRQTYPE(qtype),
(query_str == NULL ? "(empty)" : query_str))));
free(query_str);
}
succp = false;
goto retblock;
}
/**
* Read stored master DCB pointer. If master is not set, routing must
* be aborted
*/
if ((master_dcb = rses->rses_master_ref->bref_dcb) == NULL)
{
char* query_str = modutil_get_query(querybuf);
CHK_DCB(master_dcb);
LOGIF(LE, (skygw_log_write_flush(
LOGFILE_ERROR,
"Error: Can't route %s:%s:\"%s\" to "
"backend server. Session doesn't have a Master "
"node",
STRPACKETTYPE(packet_type),
STRQTYPE(qtype),
(query_str == NULL ? "(empty)" : query_str))));
free(query_str);
succp = false;
goto retblock;
}
/** If buffer is not contiguous, make it such */
if (querybuf->next != NULL)
{
querybuf = gwbuf_make_contiguous(querybuf);
}
switch(packet_type) {
case MYSQL_COM_QUIT: /*< 1 QUIT will close all sessions */
case MYSQL_COM_INIT_DB: /*< 2 DDL must go to the master */
case MYSQL_COM_REFRESH: /*< 7 - I guess this is session but not sure */
case MYSQL_COM_DEBUG: /*< 0d all servers dump debug info to stdout */
case MYSQL_COM_PING: /*< 0e all servers are pinged */
case MYSQL_COM_CHANGE_USER: /*< 11 all servers change it accordingly */
case MYSQL_COM_STMT_CLOSE: /*< free prepared statement */
case MYSQL_COM_STMT_SEND_LONG_DATA: /*< send data to column */
case MYSQL_COM_STMT_RESET: /*< resets the data of a prepared statement */
qtype = QUERY_TYPE_SESSION_WRITE;
break;
case MYSQL_COM_CREATE_DB: /**< 5 DDL must go to the master */
case MYSQL_COM_DROP_DB: /**< 6 DDL must go to the master */
qtype = QUERY_TYPE_WRITE;
break;
case MYSQL_COM_QUERY:
qtype = query_classifier_get_type(querybuf);
break;
case MYSQL_COM_STMT_PREPARE:
qtype = query_classifier_get_type(querybuf);
qtype |= QUERY_TYPE_PREPARE_STMT;
break;
case MYSQL_COM_STMT_EXECUTE:
/** Parsing is not needed for this type of packet */
qtype = QUERY_TYPE_EXEC_STMT;
break;
case MYSQL_COM_SHUTDOWN: /**< 8 where should shutdown be routed ? */
case MYSQL_COM_STATISTICS: /**< 9 ? */
case MYSQL_COM_PROCESS_INFO: /**< 0a ? */
case MYSQL_COM_CONNECT: /**< 0b ? */
case MYSQL_COM_PROCESS_KILL: /**< 0c ? */
case MYSQL_COM_TIME: /**< 0f should this be run in gateway ? */
case MYSQL_COM_DELAYED_INSERT: /**< 10 ? */
case MYSQL_COM_DAEMON: /**< 1d ? */
default:
break;
} /**< switch by packet type */
/**
* Check if the query has anything to do with temporary tables.
*/
qtype = is_read_tmp_table(rses, querybuf, qtype);
check_create_tmp_table(rses, querybuf, qtype);
check_drop_tmp_table(rses, querybuf,qtype);
/**
* If autocommit is disabled or transaction is explicitly started
* transaction becomes active and master gets all statements until
* transaction is committed and autocommit is enabled again.
*/
if (rses->rses_autocommit_enabled &&
QUERY_IS_TYPE(qtype, QUERY_TYPE_DISABLE_AUTOCOMMIT))
{
rses->rses_autocommit_enabled = false;
if (!rses->rses_transaction_active)
{
rses->rses_transaction_active = true;
}
}
else if (!rses->rses_transaction_active &&
QUERY_IS_TYPE(qtype, QUERY_TYPE_BEGIN_TRX))
{
rses->rses_transaction_active = true;
}
/**
* Explicit COMMIT and ROLLBACK, implicit COMMIT.
*/
if (rses->rses_autocommit_enabled &&
rses->rses_transaction_active &&
(QUERY_IS_TYPE(qtype,QUERY_TYPE_COMMIT) ||
QUERY_IS_TYPE(qtype,QUERY_TYPE_ROLLBACK)))
{
rses->rses_transaction_active = false;
}
else if (!rses->rses_autocommit_enabled &&
QUERY_IS_TYPE(qtype, QUERY_TYPE_ENABLE_AUTOCOMMIT))
{
rses->rses_autocommit_enabled = true;
rses->rses_transaction_active = false;
}
if (LOG_IS_ENABLED(LOGFILE_TRACE))
{
uint8_t* packet = GWBUF_DATA(querybuf);
unsigned char ptype = packet[4];
size_t len = MIN(GWBUF_LENGTH(querybuf),
MYSQL_GET_PACKET_LEN((unsigned char *)querybuf->start)-1);
char* data = (char*)&packet[5];
char* contentstr = strndup(data, len);
char* qtypestr = skygw_get_qtype_str(qtype);
skygw_log_write(
LOGFILE_TRACE,
"> Autocommit: %s, trx is %s, cmd: %s, type: %s, "
"stmt: %s%s %s",
(rses->rses_autocommit_enabled ? "[enabled]" : "[disabled]"),
(rses->rses_transaction_active ? "[open]" : "[not open]"),
STRPACKETTYPE(ptype),
(qtypestr==NULL ? "N/A" : qtypestr),
contentstr,
(querybuf->hint == NULL ? "" : ", Hint:"),
(querybuf->hint == NULL ? "" : STRHINTTYPE(querybuf->hint->type)));
free(contentstr);
free(qtypestr);
}
/**
* Find out where to route the query. Result may not be clear; it is
* possible to have a hint for routing to a named server which can
* be either slave or master.
* If query would otherwise be routed to slave then the hint determines
* actual target server if it exists.
*
* route_target is a bitfield and may include :
* TARGET_ALL
* - route to all connected backend servers
* TARGET_SLAVE[|TARGET_NAMED_SERVER|TARGET_RLAG_MAX]
* - route primarily according to hints, then to slave and if those
* failed, eventually to master
* TARGET_MASTER[|TARGET_NAMED_SERVER|TARGET_RLAG_MAX]
* - route primarily according to the hints and if they failed,
* eventually to master
*/
route_target = get_route_target(qtype,
rses->rses_transaction_active,
rses->rses_config.rw_use_sql_variables_in,
querybuf->hint);
if (TARGET_IS_ALL(route_target))
{
/**
* It is not sure if the session command in question requires
* response. Statement is examined in route_session_write.
* Router locking is done inside the function.
*/
succp = route_session_write(
rses,
gwbuf_clone(querybuf),
inst,
packet_type,
qtype);
if (succp)
{
atomic_add(&inst->stats.n_all, 1);
}
goto retblock;
}
/** Lock router session */
if (!rses_begin_locked_router_action(rses))
{
LOGIF(LT, (skygw_log_write(
LOGFILE_TRACE,
"Route query aborted! Routing session is closed <")));
succp = false;
goto retblock;
}
/**
* There is a hint which either names the target backend or
* hint which sets maximum allowed replication lag for the
* backend.
*/
if (TARGET_IS_NAMED_SERVER(route_target) ||
TARGET_IS_RLAG_MAX(route_target))
{
HINT* hint;
char* named_server = NULL;
hint = querybuf->hint;
while (hint != NULL)
{
if (hint->type == HINT_ROUTE_TO_NAMED_SERVER)
{
/**
* Set the name of searched
* backend server.
*/
named_server = hint->data;
LOGIF(LT, (skygw_log_write(
LOGFILE_TRACE,
"Hint: route to server "
"'%s'",
named_server)));
}
else if (hint->type == HINT_PARAMETER &&
(strncasecmp((char *)hint->data,
"max_slave_replication_lag",
strlen("max_slave_replication_lag")) == 0))
{
int val = (int) strtol((char *)hint->value,
(char **)NULL, 10);
if (val != 0 || errno == 0)
{
/**
* Set max. acceptable
* replication lag
* value for backend srv
*/
rlag_max = val;
LOGIF(LT, (skygw_log_write(
LOGFILE_TRACE,
"Hint: "
"max_slave_replication_lag=%d",
rlag_max)));
}
}
hint = hint->next;
} /*< while */
if (rlag_max == MAX_RLAG_UNDEFINED) /*< no rlag max hint, use config */
{
rlag_max = rses_get_max_replication_lag(rses);
}
btype = BE_UNDEFINED; /*< target may be master or slave */
/**
* Search backend server by name or replication lag.
* If it fails, then try to find valid slave or master.
*/
succp = get_dcb(&target_dcb, rses, btype, named_server,rlag_max);
if (!succp)
{
if (TARGET_IS_NAMED_SERVER(route_target))
{
LOGIF(LT, (skygw_log_write(
LOGFILE_TRACE,
"Was supposed to route to named server "
"%s but couldn't find the server in a "
"suitable state.",
named_server)));
}
else if (TARGET_IS_RLAG_MAX(route_target))
{
LOGIF(LT, (skygw_log_write(
LOGFILE_TRACE,
"Was supposed to route to server with "
"replication lag at most %d but couldn't "
"find such a slave.",
rlag_max)));
}
}
}
else if (TARGET_IS_SLAVE(route_target))
{
btype = BE_SLAVE;
if (rlag_max == MAX_RLAG_UNDEFINED) /*< no rlag max hint, use config */
{
rlag_max = rses_get_max_replication_lag(rses);
}
/**
* Search suitable backend server, get DCB in target_dcb
*/
succp = get_dcb(&target_dcb, rses, BE_SLAVE, NULL,rlag_max);
if (succp)
{
#if defined(SS_EXTRA_DEBUG)
LOGIF(LT, (skygw_log_write(LOGFILE_TRACE,
"Found DCB for slave.")));
#endif
ss_dassert(get_bref_from_dcb(rses, target_dcb) !=
rses->rses_master_ref);
ss_dassert(get_root_master_bref(rses) ==
rses->rses_master_ref);
atomic_add(&inst->stats.n_slave, 1);
}
else
{
LOGIF(LT, (skygw_log_write(LOGFILE_TRACE,
"Was supposed to route to slave"
"but finding suitable one "
"failed.")));
}
}
else if (TARGET_IS_MASTER(route_target))
{
DCB* curr_master_dcb = NULL;
succp = get_dcb(&curr_master_dcb,
rses,
BE_MASTER,
NULL,
MAX_RLAG_UNDEFINED);
if (succp && master_dcb == curr_master_dcb)
{
atomic_add(&inst->stats.n_master, 1);
target_dcb = master_dcb;
}
else
{
if (succp && master_dcb != curr_master_dcb)
{
LOGIF(LT, (skygw_log_write(LOGFILE_TRACE,
"Was supposed to "
"route to master "
"but master has "
"changed.")));
}
else
{
LOGIF(LT, (skygw_log_write(LOGFILE_TRACE,
"Was supposed to "
"route to master "
"but couldn't find "
"master in a "
"suitable state.")));
}
/**
* Master has changed. Return with error indicator.
*/
rses_end_locked_router_action(rses);
succp = false;
goto retblock;
}
}
if (succp) /*< Have DCB of the target backend */
{
backend_ref_t* bref;
sescmd_cursor_t* scur;
bref = get_bref_from_dcb(rses, target_dcb);
scur = &bref->bref_sescmd_cur;
LOGIF(LT, (skygw_log_write(
LOGFILE_TRACE,
"Route query to %s \t%s:%d <",
(SERVER_IS_MASTER(bref->bref_backend->backend_server) ?
"master" : "slave"),
bref->bref_backend->backend_server->name,
bref->bref_backend->backend_server->port)));
/**
* Store current stmt if execution of previous session command
* haven't completed yet. Note that according to MySQL protocol
* there can only be one such non-sescmd stmt at the time.
*/
if (sescmd_cursor_is_active(scur))
{
ss_dassert(bref->bref_pending_cmd == NULL);
bref->bref_pending_cmd = gwbuf_clone(querybuf);
rses_end_locked_router_action(rses);
goto retblock;
}
if ((ret = target_dcb->func.write(target_dcb, gwbuf_clone(querybuf))) == 1)
{
backend_ref_t* bref;
atomic_add(&inst->stats.n_queries, 1);
/**
* Add one query response waiter to backend reference
*/
bref = get_bref_from_dcb(rses, target_dcb);
bref_set_state(bref, BREF_QUERY_ACTIVE);
bref_set_state(bref, BREF_WAITING_RESULT);
}
else
{
LOGIF(LE, (skygw_log_write_flush(
LOGFILE_ERROR,
"Error : Routing query failed.")));
succp = false;
}
}
rses_end_locked_router_action(rses);
retblock:
#if defined(SS_DEBUG2)
{
char* canonical_query_str;
canonical_query_str = skygw_get_canonical(querybuf);
if (canonical_query_str != NULL)
{
LOGIF(LT, (skygw_log_write(
LOGFILE_TRACE,
"Canonical version: %s",
canonical_query_str)));
free(canonical_query_str);
}
}
#endif
return succp;
}
/**