MediaWiki internal error.

Original exception: exception 'DBQueryError' with message 'A database error has occurred
Query: SELECT page_restrictions FROM `page` WHERE page_id = '2614' LIMIT 1
Function: Title::loadRestrictionsFromRow
Error: 2002 Can't connect to local MySQL server through socket '/var/run/mysqld/mysqld.sock' (111) (localhost)
' in /usr/share/mediawiki1.7/includes/db/Database.php:606
Stack trace:
#0 /usr/share/mediawiki1.7/includes/db/Database.php(561): Database->reportQueryError('Can't connect t...', 2002, 'SELECT page_re...', 'Title::loadRest...', false)
#1 /usr/share/mediawiki1.7/includes/db/Database.php(969): Database->query('SELECT page_re...', 'Title::loadRest...')
#2 /usr/share/mediawiki1.7/includes/db/Database.php(886): Database->select('page', 'page_restrictio...', Array, 'Title::loadRest...', Array)
#3 /usr/share/mediawiki1.7/includes/Title.php(1742): Database->selectField('page', 'page_restrictio...', Array, 'Title::loadRest...')
#4 /usr/share/mediawiki1.7/includes/Title.php(1806): Title->loadRestrictionsFromRow(Object(ResultWrapper), NULL)
#5 /usr/share/mediawiki1.7/includes/Title.php(1853): Title->loadRestrictions()
#6 /usr/share/mediawiki1.7/includes/Title.php(1234): Title->getRestrictions('edit')
#7 /usr/share/mediawiki1.7/includes/Title.php(1048): Title->getUserPermissionsErrorsInternal('edit', Object(User), false)
#8 /usr/share/mediawiki1.7/includes/Title.php(1020): Title->userCan('edit', false)
#9 /usr/share/mediawiki1.7/includes/parser/Parser.php(3404): Title->quickUserCan('edit')
#10 /usr/share/mediawiki1.7/includes/parser/Parser.php(989): Parser->formatHeadings('Line 6:', true)
#11 /usr/share/mediawiki1.7/includes/parser/Parser.php(317): Parser->internalParse('Line 6:')
#12 /usr/share/mediawiki1.7/includes/OutputPage.php(528): Parser->parse('Line 6:', Object(Title), Object(ParserOptions), true, true, NULL)
#13 /usr/share/mediawiki1.7/includes/GlobalFunctions.php(616): OutputPage->parse('Line 6:', true, true)
#14 /usr/share/mediawiki1.7/includes/DifferenceEngine.php(576): wfMsgExt('lineno', Array, '6')
#15 [internal function]: DifferenceEngine->localiseLineNumbersCb(Array)
#16 /usr/share/mediawiki1.7/includes/DifferenceEngine.php(571): preg_replace_callback('/<!--LINE (\d+)...', Array, '<tr><td colspan...')
#17 /usr/share/mediawiki1.7/includes/DifferenceEngine.php(464): DifferenceEngine->localiseLineNumbers('<tr><td colspan...')
#18 /usr/share/mediawiki1.7/includes/DifferenceEngine.php(407): DifferenceEngine->getDiffBody()
#19 /usr/share/mediawiki1.7/includes/DifferenceEngine.php(377): DifferenceEngine->getDiff('<div id="mw-dif...', '<div id="mw-dif...')
#20 /usr/share/mediawiki1.7/includes/DifferenceEngine.php(268): DifferenceEngine->showDiff('<div id="mw-dif...', '<div id="mw-dif...')
#21 /usr/share/mediawiki1.7/includes/Article.php(729): DifferenceEngine->showDiffPage(false)
#22 /usr/share/mediawiki1.7/includes/Wiki.php(437): Article->view()
#23 /usr/share/mediawiki1.7/includes/Wiki.php(59): MediaWiki->performAction(Object(OutputPage), Object(Article), Object(Title), Object(User), Object(WebRequest))
#24 /var/lib/mediawiki1.7/index.php(93): MediaWiki->initialize(Object(Title), Object(Article), Object(OutputPage), Object(User), Object(WebRequest))
#25 {main}

Exception caught inside exception handler: exception 'DBUnexpectedError' with message 'Error in fetchObject(): Can't connect to local MySQL server through socket '/var/run/mysqld/mysqld.sock' (111) (localhost)' in /usr/share/mediawiki1.7/includes/db/Database.php:735
Stack trace:
#0 /usr/share/mediawiki1.7/includes/db/Database.php(2620): Database->fetchObject(false)
#1 /usr/share/mediawiki1.7/includes/LinkBatch.php(98): ResultWrapper->fetchObject()
#2 /usr/share/mediawiki1.7/includes/LinkBatch.php(78): LinkBatch->addResultToCache(Object(LinkCache), Object(ResultWrapper))
#3 /usr/share/mediawiki1.7/includes/LinkBatch.php(68): LinkBatch->executeInto(Object(LinkCache))
#4 /usr/share/mediawiki1.7/includes/Skin.php(208): LinkBatch->execute()
#5 /usr/share/mediawiki1.7/includes/Skin.php(184): Skin->preloadExistence()
#6 /usr/share/mediawiki1.7/includes/SkinTemplate.php(106): Skin->initPage(Object(OutputPage))
#7 /usr/share/mediawiki1.7/skins/MonoBook.php(24): SkinTemplate->initPage(Object(OutputPage))
#8 /usr/share/mediawiki1.7/includes/SkinTemplate.php(151): SkinMonoBook->initPage(Object(OutputPage))
#9 /usr/share/mediawiki1.7/includes/OutputPage.php(821): SkinTemplate->outputPage(Object(OutputPage))
#10 /usr/share/mediawiki1.7/includes/Exception.php(150): OutputPage->output()
#11 /usr/share/mediawiki1.7/includes/Exception.php(174): MWException->reportHTML()
#12 /usr/share/mediawiki1.7/includes/Exception.php(260): MWException->report()
#13 /usr/share/mediawiki1.7/includes/Exception.php(294): wfReportException(Object(DBQueryError))
#14 [internal function]: wfExceptionHandler(Object(DBQueryError))
#15 {main}