asp.net - Win32Exception (0x80004005): Access is denied -

i hosting application using windows azure servers, working fine since 1 week , when user or either me trying login application giving access denied error. if can happening application?

my connectionstring:

connectionstring="data source=129.123.144.41;initial catalog=tear;persist security info=true;user id=tearconn;password=whyyou" 

stacktrace:

[win32exception (0x80004005): access denied]  [sqlexception (0x80131904): network-related or instance-specific error occurred while establishing connection sql server. server not found or not accessible. verify instance name correct , sql server configured allow remote connections. (provider: named pipes provider, error: 40 - not open connection sql server)]    system.data.sqlclient.sqlinternalconnection.onerror(sqlexception exception, boolean breakconnection, action`1 wrapcloseinaction) +5341687    system.data.sqlclient.tdsparser.throwexceptionandwarning(tdsparserstateobject stateobj, boolean callerhasconnectionlock, boolean asyncclose) +546    system.data.sqlclient.tdsparser.connect(serverinfo serverinfo, sqlinternalconnectiontds connhandler, boolean ignoresniopentimeout, int64 timerexpire, boolean encrypt, boolean trustservercert, boolean integratedsecurity, boolean withfailover) +5353471    system.data.sqlclient.sqlinternalconnectiontds.attemptonelogin(serverinfo serverinfo, string newpassword, securestring newsecurepassword, boolean ignoresniopentimeout, timeouttimer timeout, boolean withfailover) +145    system.data.sqlclient.sqlinternalconnectiontds.loginnofailover(serverinfo serverinfo, string newpassword, securestring newsecurepassword, boolean redirecteduserinstance, sqlconnectionstring connectionoptions, sqlcredential credential, timeouttimer timeout) +892    system.data.sqlclient.sqlinternalconnectiontds.openloginenlist(timeouttimer timeout, sqlconnectionstring connectionoptions, sqlcredential credential, string newpassword, securestring newsecurepassword, boolean redirecteduserinstance) +311    system.data.sqlclient.sqlinternalconnectiontds..ctor(dbconnectionpoolidentity identity, sqlconnectionstring connectionoptions, sqlcredential credential, object providerinfo, string newpassword, securestring newsecurepassword, boolean redirecteduserinstance, sqlconnectionstring userconnectionoptions, sessiondata reconnectsessiondata) +646    system.data.sqlclient.sqlconnectionfactory.createconnection(dbconnectionoptions options, dbconnectionpoolkey poolkey, object poolgroupproviderinfo, dbconnectionpool pool, dbconnection owningconnection, dbconnectionoptions useroptions) +278    system.data.providerbase.dbconnectionfactory.createpooledconnection(dbconnectionpool pool, dbconnection owningobject, dbconnectionoptions options, dbconnectionpoolkey poolkey, dbconnectionoptions useroptions) +38    system.data.providerbase.dbconnectionpool.createobject(dbconnection owningobject, dbconnectionoptions useroptions, dbconnectioninternal oldconnection) +732    system.data.providerbase.dbconnectionpool.usercreaterequest(dbconnection owningobject, dbconnectionoptions useroptions, dbconnectioninternal oldconnection) +85    system.data.providerbase.dbconnectionpool.trygetconnection(dbconnection owningobject, uint32 waitformultipleobjectstimeout, boolean allowcreate, boolean onlyonecheckconnection, dbconnectionoptions useroptions, dbconnectioninternal& connection) +1057    system.data.providerbase.dbconnectionpool.trygetconnection(dbconnection owningobject, taskcompletionsource`1 retry, dbconnectionoptions useroptions, dbconnectioninternal& connection) +78    system.data.providerbase.dbconnectionfactory.trygetconnection(dbconnection owningconnection, taskcompletionsource`1 retry, dbconnectionoptions useroptions, dbconnectioninternal oldconnection, dbconnectioninternal& connection) +196    system.data.providerbase.dbconnectioninternal.tryopenconnectioninternal(dbconnection outerconnection, dbconnectionfactory connectionfactory, taskcompletionsource`1 retry, dbconnectionoptions useroptions) +146    system.data.providerbase.dbconnectionclosed.tryopenconnection(dbconnection outerconnection, dbconnectionfactory connectionfactory, taskcompletionsource`1 retry, dbconnectionoptions useroptions) +16    system.data.sqlclient.sqlconnection.tryopeninner(taskcompletionsource`1 retry) +94    system.data.sqlclient.sqlconnection.tryopen(taskcompletionsource`1 retry) +110    system.data.sqlclient.sqlconnection.open() +96    system.web.dataaccess.sqlconnectionholder.open(httpcontext context, boolean revertimpersonate) +88    system.web.dataaccess.sqlconnectionhelper.getconnection(string connectionstring, boolean revertimpersonation) +239    system.web.security.sqlmembershipprovider.getpasswordwithformat(string username, boolean updatelastloginactivitydate, int32& status, string& password, int32& passwordformat, string& passwordsalt, int32& failedpasswordattemptcount, int32& failedpasswordanswerattemptcount, boolean& isapproved, datetime& lastlogindate, datetime& lastactivitydate) +806    system.web.security.sqlmembershipprovider.checkpassword(string username, string password, boolean updatelastloginactivitydate, boolean failifnotapproved, string& salt, int32& passwordformat) +88    system.web.security.sqlmembershipprovider.validateuser(string username, string password) +106    system.web.ui.webcontrols.login.authenticateusingmembershipprovider(authenticateeventargs e) +59    system.web.ui.webcontrols.login.onauthenticate(authenticateeventargs e) +113    system.web.ui.webcontrols.login.attemptlogin() +119    system.web.ui.webcontrols.login.onbubbleevent(object source, eventargs e) +75    system.web.ui.control.raisebubbleevent(object source, eventargs args) +37    system.web.ui.webcontrols.button.oncommand(commandeventargs e) +114    system.web.ui.webcontrols.button.raisepostbackevent(string eventargument) +159    system.web.ui.webcontrols.button.system.web.ui.ipostbackeventhandler.raisepostbackevent(string eventargument) +10    system.web.ui.page.raisepostbackevent(ipostbackeventhandler sourcecontrol, string eventargument) +13    system.web.ui.page.raisepostbackevent(namevaluecollection postdata) +35    system.web.ui.page.processrequestmain(boolean includestagesbeforeasyncpoint, boolean includestagesafterasyncpoint) +1724