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Fix to Coverity issues 72731 and 72708

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In routeQuery: check if master has failed and in that case abort routing with an error sent back to the client.
handle_error_new_connection also tests for master failure and returns with error if that is the case.
This commit is contained in:
VilhoRaatikka
2014-11-06 22:24:12 +02:00
parent ae53ca0e44
commit 1ed3c9cc62
1 changed files with 81 additions and 33 deletions
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108
server/modules/routing/readwritesplit/readwritesplit.c
View File

@ -1719,27 +1719,41 @@ static int routeQuery(
LOGIF(LE,
(skygw_log_write_flush(
LOGFILE_ERROR,
"Error: Failed to route %s:%s:\"%s\" to "
"backend server. %s.",
"Error: Can't route %s:%s:\"%s\" to "
"backend server. Router is closed.",
STRPACKETTYPE(packet_type),
STRQTYPE(qtype),
(query_str == NULL ? "(empty)" : query_str),
(rses_is_closed ? "Router was closed" :
"Router has no backend servers where to "
"route to"))));
(query_str == NULL ? "(empty)" : query_str))));
free(query_str);
}
ret = 0;
goto retblock;
}
/** Read stored master DCB pointer */
if ((master_dcb = router_cli_ses->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);
ret = 0;
goto retblock;
}
/** If buffer is not contiguous, make it such */
if (querybuf->next != NULL)
{
querybuf = gwbuf_make_contiguous(querybuf);
}
/** Read stored master DCB pointer */
master_dcb = router_cli_ses->rses_master_ref->bref_dcb;
CHK_DCB(master_dcb);
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 */
@ -2035,7 +2049,7 @@ static int routeQuery(
NULL,
MAX_RLAG_UNDEFINED);
if (succp && (master_dcb == NULL || master_dcb == curr_master_dcb))
if (succp && master_dcb == curr_master_dcb)
{
atomic_add(&inst->stats.n_master, 1);
target_dcb = master_dcb;
@ -4082,6 +4096,22 @@ static void handleError (
return;
}
if (rses->rses_master_ref->bref_dcb == backend_dcb)
{
/** Master failed, can't recover */
LOGIF(LE, (skygw_log_write_flush(
LOGFILE_ERROR,
"Error : Master node have failed. "
"Session will be closed.")));
*succp = false;
rses_end_locked_router_action(rses);
return;
}
/**
* This is called in hope of getting replacement for
* failed slave(s).
*/
*succp = handle_error_new_connection(inst,
rses,
backend_dcb,
@ -4124,7 +4154,18 @@ static void handle_error_reply_client(
}
/**
* This must be called with router lock
* Check if there is backend reference pointing at failed DCB, and reset its
* flags. Then clear DCB's callback and finally : try to find replacement(s)
* for failed slave(s).
*
* This must be called with router lock.
*
* @param inst router instance
* @param rses router client session
* @param dcb failed DCB
* @param errmsg error message which is sent to client if it is waiting
*
* @return true if there are enough backend connections to continue, false if not
*/
static bool handle_error_new_connection(
ROUTER_INSTANCE* inst,
@ -4144,25 +4185,14 @@ static bool handle_error_new_connection(
ses = backend_dcb->session;
CHK_SESSION(ses);
bref = get_bref_from_dcb(rses, backend_dcb);
/** failed DCB has already been replaced */
if (bref == NULL)
{
succp = true;
goto return_succp;
}
/**
* Error handler is already called for this DCB because
* it's not polling anymore. It can be assumed that
* it succeed because rses isn't closed.
* If bref == NULL it has been replaced already with another one.
*/
if (backend_dcb->state != DCB_STATE_POLLING)
if ((bref = get_bref_from_dcb(rses, backend_dcb)) == NULL)
{
succp = true;
goto return_succp;
}
CHK_BACKEND_REF(bref);
if (BREF_IS_WAITING_RESULT(bref))
@ -4174,6 +4204,17 @@ static bool handle_error_new_connection(
}
bref_clear_state(bref, BREF_IN_USE);
bref_set_state(bref, BREF_CLOSED);
/**
* Error handler is already called for this DCB because
* it's not polling anymore. It can be assumed that
* it succeed because rses isn't closed.
*/
if (backend_dcb->state != DCB_STATE_POLLING)
{
succp = true;
goto return_succp;
}
/**
* Remove callback because this DCB won't be used
* unless it is reconnected later, and then the callback
@ -4298,8 +4339,8 @@ static bool have_enough_servers(
}
else
{
double pct = (*p_rses)->rses_config.rw_max_slave_conn_percent/100;
double nservers = (double)router_nsrv*pct;
int pct = (*p_rses)->rses_config.rw_max_slave_conn_percent/100;
int nservers = router_nsrv*pct;
if ((*p_rses)->rses_config.rw_max_slave_conn_count < min_nsrv)
{
@ -4318,11 +4359,11 @@ static bool have_enough_servers(
LOGFILE_ERROR,
"Error : Unable to start %s service. There are "
"too few backend servers configured in "
"MaxScale.cnf. Found %d%% when at least %.0f%% "
"MaxScale.cnf. Found %d%% when at least %d%% "
"would be required.",
router->service->name,
(*p_rses)->rses_config.rw_max_slave_conn_percent,
min_nsrv/(((double)router_nsrv)/100))));
min_nsrv/(router_nsrv/100))));
}
}
free(*p_rses);
@ -4385,7 +4426,14 @@ static int rses_get_max_replication_lag(
return conf_max_rlag;
}
/**
* Finds out if there is a backend reference pointing at the DCB given as
* parameter.
* @param rses router client session
* @param dcb DCB
*
* @return backend reference pointer if succeed or NULL
*/
static backend_ref_t* get_bref_from_dcb(
ROUTER_CLIENT_SES* rses,
DCB* dcb)