删除板块提示2002数据库链接错误

      今天在删除不想要的板块的时候，帖子不多的板块可以很顺利的删除，但帖子数很多的板块，删除后等好长时间，提示2002，数据库链接错误，求助。
Discuz! Database Error(2002) notconnect
PHP Debug

No.	File	Line	Code
1	admin.php	25	discuz_application->init()
2	source/class/discuz/discuz_application.php	65	discuz_application->_init_db()
3	source/class/discuz/discuz_application.php	373	discuz_database::init(%s, Array)
4	source/class/discuz/discuz_database.php	23	db_driver_mysql->connect()
5	source/class/db/db_driver_mysql.php	74	db_driver_mysql->_dbconnect(%s, %s, %s, %s, %s, %s)
6	source/class/db/db_driver_mysql.php	87	db_driver_mysql->halt(%s, %d)
7	source/class/db/db_driver_mysql.php	218	break()