MediaWiki internal error.

Original exception: exception 'DBQueryError' with message 'A database error has occurred
Query: SHOW STATUS LIKE 'Thread%'
Function:
Error: 2006 MySQL server has gone away (localhost)
' in /var/www/bear.climb.com.tw/html/modules/mediawiki/includes/Database.php:673
Stack trace:
#0 /var/www/bear.climb.com.tw/html/modules/mediawiki/includes/Database.php(630): mwDatabase->reportQueryError('MySQL server ha...', 2006, 'SHOW STATUS LIK...', '', false)
#1 /var/www/bear.climb.com.tw/html/modules/mediawiki/includes/Database.php(1864): mwDatabase->query('SHOW STATUS LIK...')
#2 /var/www/bear.climb.com.tw/html/modules/mediawiki/includes/LoadBalancer.php(197): mwDatabase->getStatus('Thread%')
#3 /var/www/bear.climb.com.tw/html/modules/mediawiki/includes/LoadBalancer.php(364): LoadBalancer->getReaderIndex()
#4 /var/www/bear.climb.com.tw/html/modules/mediawiki/includes/DatabaseFunctions.php(52): LoadBalancer->getConnection(-1, true, Array)
#5 /var/www/bear.climb.com.tw/html/modules/mediawiki/includes/Title.php(2178): wfGetDB(-1)
#6 /var/www/bear.climb.com.tw/html/modules/mediawiki/includes/DifferenceEngine.php(49): Title->getPreviousRevisionID(1935)
#7 /var/www/bear.climb.com.tw/html/modules/mediawiki/includes/Article.php(657): DifferenceEngine->DifferenceEngine(Object(Title), 1935, 'prev', NULL)
#8 /var/www/bear.climb.com.tw/html/modules/mediawiki/includes/Wiki.php(327): Article->view()
#9 /var/www/bear.climb.com.tw/html/modules/mediawiki/includes/Wiki.php(50): MediaWiki->performAction(Object(XoopsOutputPage), Object(Article), Object(Title), Object(User), Object(WebRequest))
#10 /var/www/bear.climb.com.tw/html/modules/mediawiki/index.php(123): MediaWiki->initialize(Object(Title), Object(XoopsOutputPage), Object(User), Object(WebRequest))
#11 {main}

Exception caught inside exception handler: exception 'DBUnexpectedError' with message 'Error in fetchObject(): MySQL server has gone away' in /var/www/bear.climb.com.tw/html/modules/mediawiki/includes/Database.php:790
Stack trace:
#0 /var/www/bear.climb.com.tw/html/modules/mediawiki/includes/Database.php(1866): mwDatabase->fetchObject(false)
#1 /var/www/bear.climb.com.tw/html/modules/mediawiki/includes/LoadBalancer.php(197): mwDatabase->getStatus('Thread%')
#2 /var/www/bear.climb.com.tw/html/modules/mediawiki/includes/LoadBalancer.php(364): LoadBalancer->getReaderIndex()
#3 /var/www/bear.climb.com.tw/html/modules/mediawiki/includes/DatabaseFunctions.php(52): LoadBalancer->getConnection(-1, true, Array)
#4 /var/www/bear.climb.com.tw/html/modules/mediawiki/includes/LinkBatch.php(124): wfGetDB(-1)
#5 /var/www/bear.climb.com.tw/html/modules/mediawiki/includes/LinkBatch.php(80): LinkBatch->doQuery()
#6 /var/www/bear.climb.com.tw/html/modules/mediawiki/includes/LinkBatch.php(69): LinkBatch->executeInto(Object(LinkCache))
#7 /var/www/bear.climb.com.tw/html/modules/mediawiki/includes/Skin.php(194): LinkBatch->execute()
#8 /var/www/bear.climb.com.tw/html/modules/mediawiki/includes/Skin.php(173): Skin->preloadExistence()
#9 /var/www/bear.climb.com.tw/html/modules/mediawiki/includes/SkinTemplate.php(108): Skin->initPage(Object(XoopsOutputPage))
#10 /var/www/bear.climb.com.tw/html/modules/mediawiki/skins/MonoBook.php(28): SkinTemplate->initPage(Object(XoopsOutputPage))
#11 /var/www/bear.climb.com.tw/html/modules/mediawiki/includes/SkinTemplate.php(155): SkinMonoBook->initPage(Object(XoopsOutputPage))
#12 /var/www/bear.climb.com.tw/html/modules/mediawiki/include/XoopsOutputPage.php(273): SkinTemplate->outputPage(Object(XoopsOutputPage))
#13 /var/www/bear.climb.com.tw/html/modules/mediawiki/include/XoopsOutputPage.php(136): XoopsOutputPage->outputmediawiki()
#14 /var/www/bear.climb.com.tw/html/modules/mediawiki/includes/Exception.php(53): XoopsOutputPage->output()
#15 /var/www/bear.climb.com.tw/html/modules/mediawiki/includes/Exception.php(70): MWException->reportHTML()
#16 /var/www/bear.climb.com.tw/html/modules/mediawiki/includes/Exception.php(145): MWException->report()
#17 /var/www/bear.climb.com.tw/html/modules/mediawiki/includes/Exception.php(179): wfReportException(Object(DBQueryError))
#18 [internal function]: wfExceptionHandler(Object(DBQueryError))
#19 {main}