Introducing MySQL Reconnect

* mysql_reconnect_type
** 1: when mysql disconnects during runtime, the server tries to reconnect mysql_reconnect_count times and, if unsuccessful, the server is shut down
** 2: when mysql disconnects during runtime it tries to reconnect indefinitely
mysql_reconnect_type:2
* mysql_reconnect_count
** number of reconnect attempts the server should do when the database disconnects during runtime
** only used when mysql_reconnect_type is 1
mysql_reconnect_count:1
~Ind

Signed-off-by: shennetsind <ind@henn.et>

1 files changed, 73 insertions, 1 deletions

diff --git a/src/common/sql.c b/src/common/sql.c
index 800aa89b0..96346d68c 100644
--- a/src/common/sql.c
+++ b/src/common/sql.c
@@ -15,7 +15,10 @@
 #include <string.h>// strlen/strnlen/memcpy/memset
 #include <stdlib.h>// strtoul
 
+void hercules_mysql_error_handler(unsigned int ecode);
 
+int mysql_reconnect_type;
+int mysql_reconnect_count;
 
 /// Sql handle
 struct Sql
@@ -74,7 +77,7 @@ Sql* Sql_Malloc(void)
 	self->lengths = NULL;
 	self->result = NULL;
 	self->keepalive = INVALID_TIMER;
-
+	self->handle.reconnect = 1;
 	return self;
 }
 
@@ -266,12 +269,14 @@ int Sql_QueryV(Sql* self, const char* query, va_list args)
 	if( mysql_real_query(&self->handle, StringBuf_Value(&self->buf), (unsigned long)StringBuf_Length(&self->buf)) )
 	{
 		ShowSQL("DB error - %s\n", mysql_error(&self->handle));
+		hercules_mysql_error_handler(mysql_errno(&self->handle));
 		return SQL_ERROR;
 	}
 	self->result = mysql_store_result(&self->handle);
 	if( mysql_errno(&self->handle) != 0 )
 	{
 		ShowSQL("DB error - %s\n", mysql_error(&self->handle));
+		hercules_mysql_error_handler(mysql_errno(&self->handle));
 		return SQL_ERROR;
 	}
 	return SQL_SUCCESS;
@@ -291,12 +296,14 @@ int Sql_QueryStr(Sql* self, const char* query)
 	if( mysql_real_query(&self->handle, StringBuf_Value(&self->buf), (unsigned long)StringBuf_Length(&self->buf)) )
 	{
 		ShowSQL("DB error - %s\n", mysql_error(&self->handle));
+		hercules_mysql_error_handler(mysql_errno(&self->handle));
 		return SQL_ERROR;
 	}
 	self->result = mysql_store_result(&self->handle);
 	if( mysql_errno(&self->handle) != 0 )
 	{
 		ShowSQL("DB error - %s\n", mysql_error(&self->handle));
+		hercules_mysql_error_handler(mysql_errno(&self->handle));
 		return SQL_ERROR;
 	}
 	return SQL_SUCCESS;
@@ -639,6 +646,7 @@ int SqlStmt_PrepareV(SqlStmt* self, const char* query, va_list args)
 	if( mysql_stmt_prepare(self->stmt, StringBuf_Value(&self->buf), (unsigned long)StringBuf_Length(&self->buf)) )
 	{
 		ShowSQL("DB error - %s\n", mysql_stmt_error(self->stmt));
+		hercules_mysql_error_handler(mysql_stmt_errno(self->stmt));
 		return SQL_ERROR;
 	}
 	self->bind_params = false;
@@ -660,6 +668,7 @@ int SqlStmt_PrepareStr(SqlStmt* self, const char* query)
 	if( mysql_stmt_prepare(self->stmt, StringBuf_Value(&self->buf), (unsigned long)StringBuf_Length(&self->buf)) )
 	{
 		ShowSQL("DB error - %s\n", mysql_stmt_error(self->stmt));
+		hercules_mysql_error_handler(mysql_stmt_errno(self->stmt));
 		return SQL_ERROR;
 	}
 	self->bind_params = false;
@@ -721,12 +730,14 @@ int SqlStmt_Execute(SqlStmt* self)
 		mysql_stmt_execute(self->stmt) )
 	{
 		ShowSQL("DB error - %s\n", mysql_stmt_error(self->stmt));
+		hercules_mysql_error_handler(mysql_stmt_errno(self->stmt));
 		return SQL_ERROR;
 	}
 	self->bind_columns = false;
 	if( mysql_stmt_store_result(self->stmt) )// store all the data
 	{
 		ShowSQL("DB error - %s\n", mysql_stmt_error(self->stmt));
+		hercules_mysql_error_handler(mysql_stmt_errno(self->stmt));
 		return SQL_ERROR;
 	}
 
@@ -868,6 +879,7 @@ int SqlStmt_NextRow(SqlStmt* self)
 	if( err )
 	{
 		ShowSQL("DB error - %s\n", mysql_stmt_error(self->stmt));
+		hercules_mysql_error_handler(mysql_stmt_errno(self->stmt));
 		return SQL_ERROR;
 	}
 
@@ -946,3 +958,63 @@ void SqlStmt_Free(SqlStmt* self)
 		aFree(self);
 	}
 }
+/* receives mysql error codes during runtime (not on first-time-connects) */
+void hercules_mysql_error_handler(unsigned int ecode) {
+	static unsigned int retry = 1;
+	switch( ecode ) {
+		case 2003:/* Can't connect to MySQL (this error only happens here when failing to reconnect) */
+			if( mysql_reconnect_type == 1 ) {
+				if( ++retry > mysql_reconnect_count ) {
+					ShowFatalError("MySQL has been unreachable for too long, %d reconnects were attempted. Shutting Down\n", retry);
+					exit(EXIT_FAILURE);
+				}
+			}
+			break;
+	}
+}
+void Sql_inter_server_read(const char* cfgName, bool first) {
+	int i;
+	char line[1024], w1[1024], w2[1024];
+	FILE* fp;
+	
+	fp = fopen(cfgName, "r");
+	if(fp == NULL) {
+		if( first ) {
+			ShowFatalError("File not found: %s\n", cfgName);
+			exit(EXIT_FAILURE);
+		} else
+			ShowError("File not found: %s\n", cfgName);
+		return;
+	}
+	
+	while(fgets(line, sizeof(line), fp)) {
+		i = sscanf(line, "%[^:]: %[^\r\n]", w1, w2);
+		if(i != 2)
+			continue;
+		
+		if(!strcmpi(w1,"mysql_reconnect_type")) {
+			mysql_reconnect_type = atoi(w2);
+			switch( mysql_reconnect_type ) {
+				case 1:
+				case 2:
+					break;
+				default:
+					ShowError("%s::mysql_reconnect_type is set to %d which is not valid, defaulting to 1...\n", cfgName, mysql_reconnect_type);
+					mysql_reconnect_type = 1;
+					break;
+			}
+		} else if(!strcmpi(w1,"mysql_reconnect_count")) {
+			mysql_reconnect_count = atoi(w2);
+			if( mysql_reconnect_count < 1 )
+				mysql_reconnect_count = 1;
+		} else if(!strcmpi(w1,"import"))
+			Sql_inter_server_read(w2,false);
+	}
+	fclose(fp);
+		
+	return;
+}
+
+void Sql_Init(void) {
+	Sql_inter_server_read("conf/inter-server.conf",true);
+}