implement mysql query wrapper function to catch transient errors

medmysql.c

@@ -1,6 +1,7 @@
 #include <my_global.h>
 #include <m_string.h>
 #include <mysql.h>
+#include <mysql/errmsg.h>
 
 #include "medmysql.h"
 #include "config.h"
@@ -26,6 +27,27 @@ static MYSQL *prov_handler = NULL;
 static int medmysql_flush_cdr(struct medmysql_batches *);
 static int medmysql_flush_medlist(struct medmysql_str *);
 
+
+static int mysql_query_wrapper(MYSQL *mysql, const char *stmt_str, unsigned long length) {
+	int ret;
+	int i;
+	unsigned int err;
+
+	for (i = 0; i < 10; i++) {
+		ret = mysql_real_query(mysql, stmt_str, length);
+		if (!ret)
+			return ret;
+		err = mysql_errno(mysql);
+		if (err == CR_SERVER_GONE_ERROR || err == CR_SERVER_LOST) {
+			syslog(LOG_WARNING, "Lost connection to SQL server during query, retrying...");
+			sleep(10);
+			continue;
+		}
+		break;
+	}
+	return ret;
+}
+
 /**********************************************************************/
 int medmysql_init()
 {
@@ -117,7 +139,7 @@ int medmysql_fetch_callids(med_callid_t **callids, u_int64_t *count)
 	
 	/*syslog(LOG_DEBUG, "q='%s'", query);*/
 
-	if(mysql_real_query(med_handler, query, strlen(query)) != 0)
+	if(mysql_query_wrapper(med_handler, query, strlen(query)) != 0)
 	{
 		syslog(LOG_CRIT, "Error getting acc callids: %s", 
 				mysql_error(med_handler));
@@ -175,7 +197,7 @@ int medmysql_fetch_records(med_callid_t *callid,
 	
 	/*syslog(LOG_DEBUG, "q='%s'", query);*/
 
-	if(mysql_real_query(med_handler, query, strlen(query)) != 0)
+	if(mysql_query_wrapper(med_handler, query, strlen(query)) != 0)
 	{
 		syslog(LOG_CRIT, "Error getting acc records for callid '%s': %s", 
 				callid->value, mysql_error(med_handler));
@@ -382,7 +404,7 @@ int medmysql_load_maps(GHashTable *host_table, GHashTable *ip_table)
 	snprintf(query, sizeof(query), MED_LOAD_PEER_QUERY);
 
 	/* syslog(LOG_DEBUG, "q='%s'", query); */
-	if(mysql_real_query(prov_handler, query, strlen(query)) != 0)
+	if(mysql_query_wrapper(prov_handler, query, strlen(query)) != 0)
 	{
 		syslog(LOG_CRIT, "Error loading peer hosts: %s", 
 				mysql_error(prov_handler));
@@ -462,7 +484,7 @@ int medmysql_load_uuids(GHashTable *uuid_table)
 	snprintf(query, sizeof(query), MED_LOAD_UUID_QUERY);
 
 	/* syslog(LOG_DEBUG, "q='%s'", query); */
-	if(mysql_real_query(prov_handler, query, strlen(query)) != 0)
+	if(mysql_query_wrapper(prov_handler, query, strlen(query)) != 0)
 	{
 		syslog(LOG_CRIT, "Error loading uuids: %s", 
 				mysql_error(prov_handler));
@@ -499,9 +521,9 @@ out:
 
 
 int medmysql_batch_start(struct medmysql_batches *batches) {
-	if (mysql_real_query(cdr_handler, "start transaction", 17))
+	if (mysql_query_wrapper(cdr_handler, "start transaction", 17))
 		return -1;
-	if (mysql_real_query(med_handler, "start transaction", 17))
+	if (mysql_query_wrapper(med_handler, "start transaction", 17))
 		return -1;
 
 	batches->cdrs.len = 0;
@@ -522,7 +544,7 @@ static int medmysql_flush_cdr(struct medmysql_batches *batches) {
 	batches->cdrs.len--;
 	batches->cdrs.str[batches->cdrs.len] = '\0';
 
-	if(mysql_real_query(cdr_handler, batches->cdrs.str, batches->cdrs.len) != 0)
+	if(mysql_query_wrapper(cdr_handler, batches->cdrs.str, batches->cdrs.len) != 0)
 	{
 		batches->cdrs.len = 0;
 		syslog(LOG_CRIT, "Error inserting cdrs: %s", 
@@ -542,7 +564,7 @@ static int medmysql_flush_medlist(struct medmysql_str *str) {
 
 	str->str[str->len - 1] = ')';
 
-	if(mysql_real_query(med_handler, str->str, str->len) != 0)
+	if(mysql_query_wrapper(med_handler, str->str, str->len) != 0)
 	{
 		str->len = 0;
 		syslog(LOG_CRIT, "Error executing query: %s", 
@@ -565,9 +587,9 @@ int medmysql_batch_end(struct medmysql_batches *batches) {
 	if (medmysql_flush_medlist(&batches->to_delete))
 		return -1;
 
-	if (mysql_real_query(cdr_handler, "commit", 6))
+	if (mysql_query_wrapper(cdr_handler, "commit", 6))
 		return -1;
-	if (mysql_real_query(med_handler, "commit", 6))
+	if (mysql_query_wrapper(med_handler, "commit", 6))
 		return -1;
 
 	return 0;