/// <summary>
/// Prevent SPAM by suppressing frequent exceptions.
/// For example it can allow maximum 10 errors of same type per 5 minutes (2880 per day).
/// Amount of suppressed exceptions will be included inside next exception which is not suppressed.
/// </summary>
bool GroupExceptions(List <ExceptionGroup> group, Exception ex, string subject, string body, Action <Exception, string, string> action)
{
var value = ex.StackTrace == null
? string.Format("{0}: {1}", ex.GetType().Name, ex.Message)
: ex.StackTrace.ToString();
// Get checksum.
var algorithm = System.Security.Cryptography.SHA256.Create();
var bytes = System.Text.Encoding.UTF8.GetBytes(value);
var hash = algorithm.ComputeHash(bytes);
algorithm.Dispose();
var guidBytes = new byte[16];
Array.Copy(hash, guidBytes, guidBytes.Length);
var checksum = new Guid(guidBytes);
// Try to get existing exception.
lock (group)
{
var ei = group.FirstOrDefault(x => x.Checksum == checksum);
var notifyNow = ei == null;
if (ei == null)
{
ei = new ExceptionGroup(group, GroupingDelay, ex, checksum, subject, body, action);
group.Add(ei);
}
ei.Increment();
return(notifyNow);
}
}
public void Save(int exceptionGroupId, string userComment, string userFixedInCommitHash)
{
ExceptionGroup exceptionGroup = _db.ExceptionGroups.First(eg => eg.ExceptionGroupId == exceptionGroupId);
exceptionGroup.UserComment = userComment;
exceptionGroup.UserFixedInCommitId = SourceControlRepository.FindCommitId(userFixedInCommitHash);
_db.SaveChanges();
}
protected void PreProcessExceptions()
{
List <ExceptionImport> exceptions = (from s in message.Sessions
from e in s.Exceptions
select new ExceptionImport(e)
{
ClientSessionId = s.SessionID,
IsFirstInSession = false
}).ToList();
if (0 == exceptions.Count)
{
return; // no exceptions reported, denormalisedExceptions remains null
}
// mark first exception in session - note that above LINQ query does not mix up order of items
long clientSession = -1;
exceptions.ForEach(ex =>
{
if (ex.ClientSessionId != clientSession)
{
ex.IsFirstInSession = true;
clientSession = ex.ClientSessionId;
}
});
List <string> distinctMsgExceptionGroups = (from e in exceptions
select e.FingerprintHash).Distinct().ToList();
List <string> knownExceptionGroups = ImportCache.GetExceptionGroupFingerprintHashes(repository);
List <string> missing = distinctMsgExceptionGroups.Except(knownExceptionGroups).ToList();
if (missing.Count > 0)
{
List <ExceptionImport> groupsToAdd = (from e in exceptions
join m in missing on e.FingerprintHash equals m
select e).Distinct(new ExceptionImportGroupEqualityComparer()).ToList();
foreach (ExceptionImport imp in groupsToAdd)
{
ExceptionGroup modelGroup = new ExceptionGroup()
{
ExceptionFingerprint = imp.Fingerprint,
ExceptionLocation = imp.Location,
ExceptionType = imp.Type,
TypeFingerprintSha256Hash = imp.FingerprintHash
};
repository.Context.ExceptionGroups.AddObject(modelGroup);
}
repository.IgnoreDuplicateKeysOnSaveChanges <ExceptionGroup>();
ImportCache.InvalidateExceptionGroupsCaches();
}
this.denormalisedExceptions = exceptions;
}