DB Error: MySQL server has gone away

Stack Trace:

File: /var/www/html/classes/issue/IssueDAO.inc.php line 131
Function: DAO->retrieve("SELECT i.* FROM issues i INNER JOIN issue_settings ist ON i.i...", Array(2))

File: /var/www/html/classes/issue/IssueDAO.inc.php line 96
Function: IssueDAO->getIssuesBySetting("pub-id::publisher-id", "270", Null)

File: /var/www/html/classes/issue/IssueDAO.inc.php line 182
Function: IssueDAO->getIssueByPubId("publisher-id", "270", Null, False)

File: /var/www/html/classes/issue/IssueDAO.inc.php line 26
Function: IssueDAO->getIssueByBestIssueId("270", Null, False)

File: (unknown) line (unknown)
Function: IssueDAO->_cacheMiss(Object(GenericCache), "270")

File: /var/www/html/lib/pkp/classes/cache/GenericCache.inc.php line 63
Function: call_user_func_array(Array(2), Array(2))

File: /var/www/html/classes/issue/IssueDAO.inc.php line 51
Function: GenericCache->get("270")

File: /var/www/html/pages/article/ArticleHandler.inc.php line 433
Function: IssueDAO->getIssueById("270", "25", True)

File: /var/www/html/pages/article/ArticleHandler.inc.php line 55
Function: ArticleHandler->validate(Object(Request), "2960", 0)

File: (unknown) line (unknown)
Function: ArticleHandler->view(Array(1), Object(Request))

File: /var/www/html/lib/pkp/classes/core/PKPRouter.inc.php line 362
Function: call_user_func(Array(2), Array(1), Object(Request))

File: /var/www/html/lib/pkp/classes/core/PKPPageRouter.inc.php line 220
Function: PKPRouter->_authorizeInitializeAndCallRequest(Array(2), Object(Request), Array(1), False)

File: /var/www/html/lib/pkp/classes/core/Dispatcher.inc.php line 134
Function: PKPPageRouter->route(Object(Request))

File: /var/www/html/lib/pkp/classes/core/PKPApplication.inc.php line 178
Function: Dispatcher->dispatch(Object(Request))

File: /var/www/html/index.php line 69
Function: PKPApplication->execute()

DB Error: MySQL server has gone away

Stack Trace:

File: /var/www/html/lib/pkp/classes/session/SessionDAO.inc.php line 119
Function: DAO->update("UPDATE sessions SET user_id = ?, ip_address = ?, ...", Array(9))

File: /var/www/html/lib/pkp/classes/session/SessionManager.inc.php line 186
Function: SessionDAO->updateObject(Object(Session))

File: (unknown) line (unknown)
Function: SessionManager->write("pqmode05f7mbilsb8alv3sben4", "")

File: (unknown) line (unknown)
Function: session_write_close()