private void InitializeReadModelInfo()
{
using (var db = createReadModelDbContext())
{
EnsureLockResourceNameIsInitialized(db);
var existingReadModelInfoNames = GetProjectorNames();
var existingReadModelInfos = db.Set <ReadModelInfo>()
.OrderBy(i => i.Name)
.Where(i => existingReadModelInfoNames.Contains(i.Name))
.ToList();
unsubscribedReadModelInfos = new List <ReadModelInfo>(existingReadModelInfos);
subscribedReadModelInfos = new List <ReadModelInfo>();
// create ReadModelInfo entries for any projectors that don't already have them
foreach (var projector in projectors.Where(p => !unsubscribedReadModelInfos.Select(i => i.Name).Contains(ReadModelInfo.NameForProjector(p))))
{
var readModelInfo = new ReadModelInfo
{
Name = ReadModelInfo.NameForProjector(projector)
};
db.Set <ReadModelInfo>().Add(readModelInfo);
unsubscribedReadModelInfos.Add(readModelInfo);
}
db.SaveChanges();
}
}
internal static void ReportFailure(
Domain.EventHandlingError error,
Func <DbContext> createDbContext)
{
// add an EventHandlingError entry as well
EventHandlingError sqlError = CreateEventHandlingError((dynamic)error);
var errorText = new
{
error.Exception,
Event = sqlError.SerializedEvent
}.ToJson();
log.Write(() => errorText);
using (var transaction = new TransactionScope(TransactionScopeOption.Suppress))
using (var db = createDbContext())
{
var dbSet = db.Set <ReadModelInfo>();
var handler = error.Handler;
string readModelInfoName = null;
if (handler != null)
{
// update the affected ReadModelInfo
readModelInfoName = ReadModelInfo.NameForProjector(handler);
var readModelInfo = dbSet.SingleOrDefault(i => i.Name == readModelInfoName);
if (readModelInfo == null)
{
readModelInfo = new ReadModelInfo {
Name = readModelInfoName
};
dbSet.Add(readModelInfo);
}
readModelInfo.Error = errorText;
readModelInfo.FailedOnEventId = sqlError.OriginalId;
}
sqlError.Error = error.Exception.ToJson();
sqlError.Handler = readModelInfoName;
db.Set <EventHandlingError>().Add(sqlError);
db.SaveChanges();
transaction.Complete();
}
}
private void EnsureInitialized()
{
if (subscribedReadModelInfos != null)
{
return;
}
// figure out which event types we will need to query
matchEvents = projectors.SelectMany(p => p.MatchesEvents())
.Distinct()
.Select(m =>
{
// TODO: (EnsureInitialized) optimize this by figuring out how to query SteamName LIKE 'Scheduled:%'
if (m.Type == "Scheduled")
{
return(new MatchEvent(m.StreamName, "*"));
}
return(m);
})
.ToArray();
Debug.WriteLine(string.Format("Catchup {0}: Subscribing to event types: {1}", Name, matchEvents.Select(m => m.ToString()).ToJson()));
using (var db = CreateReadModelDbContext())
{
EnsureLockResourceNameIsInitialized(db);
var existingReadModelInfoNames = GetProjectorNames();
var existingReadModelInfos = db.Set <ReadModelInfo>()
.OrderBy(i => i.Name)
.Where(i => existingReadModelInfoNames.Contains(i.Name))
.ToList();
unsubscribedReadModelInfos = new List <ReadModelInfo>(existingReadModelInfos);
subscribedReadModelInfos = new List <ReadModelInfo>();
// create ReadModelInfo entries for any projectors that don't already have them
foreach (var projector in projectors.Where(p => !unsubscribedReadModelInfos.Select(i => i.Name).Contains(ReadModelInfo.NameForProjector(p))))
{
var readModelInfo = new ReadModelInfo
{
Name = ReadModelInfo.NameForProjector(projector)
};
db.Set <ReadModelInfo>().Add(readModelInfo);
unsubscribedReadModelInfos.Add(readModelInfo);
}
db.SaveChanges();
}
}
private void IncludeReadModelsNeeding(StorableEvent storedEvent)
{
if (unsubscribedReadModelInfos.Count > 0)
{
foreach (var readmodelInfo in unsubscribedReadModelInfos.ToArray())
{
if (storedEvent.Id >= readmodelInfo.CurrentAsOfEventId + 1)
{
var handler = projectors.Single(p => ReadModelInfo.NameForProjector(p) == readmodelInfo.Name);
disposables.Add(bus.Subscribe(handler));
unsubscribedReadModelInfos.Remove(readmodelInfo);
subscribedReadModelInfos.Add(readmodelInfo);
}
}
}
}
internal static void ReportFailure(
Domain.EventHandlingError error,
Func <DbContext> createDbContext)
{
// add an EventHandlingError entry as well
EventHandlingError sqlError = CreateEventHandlingError((dynamic)error);
log.Write(() => new { error.Exception, sqlError.SerializedEvent });
using (var db = createDbContext())
{
var dbSet = db.Set <ReadModelInfo>();
var handler = error.Handler;
string readModelInfoName = null;
var exceptionJson = error.Exception.ToDiagnosticJson();
if (handler != null)
{
// update the affected ReadModelInfo
readModelInfoName = ReadModelInfo.NameForProjector(handler);
var readModelInfo = dbSet.SingleOrDefault(i => i.Name == readModelInfoName);
if (readModelInfo == null)
{
readModelInfo = new ReadModelInfo {
Name = readModelInfoName
};
dbSet.Add(readModelInfo);
}
readModelInfo.LastError = exceptionJson;
readModelInfo.FailedOnEventId = sqlError.EventId;
}
sqlError.Error = $"{Environment.MachineName}: {exceptionJson}";
sqlError.Handler = readModelInfoName;
db.Set <EventHandlingError>().Add(sqlError);
db.SaveChanges();
}
}
private long StreamEventsToProjections(ExclusiveEventStoreCatchupQuery query)
{
long eventsProcessed = 0;
foreach (var storedEvent in query.Events)
{
eventsProcessed++;
if (unsubscribedReadModelInfos.Count > 0)
{
foreach (var readmodelInfo in unsubscribedReadModelInfos.ToArray())
{
if (storedEvent.Id >= readmodelInfo.CurrentAsOfEventId + 1)
{
var handler = projectors.Single(p => ReadModelInfo.NameForProjector(p) == readmodelInfo.Name);
disposables.Add(bus.Subscribe(handler));
unsubscribedReadModelInfos.Remove(readmodelInfo);
subscribedReadModelInfos.Add(readmodelInfo);
}
}
}
if (cancellationDisposable.IsDisposed)
{
break;
}
IEvent @event = null;
var now = Clock.Now();
try
{
// update projectors
@event = storedEvent.ToDomainEvent();
if (@event != null)
{
using (var work = CreateUnitOfWork(@event))
{
bus.PublishAsync(@event).Wait();
var infos = work.Resource <DbContext>().Set <ReadModelInfo>();
subscribedReadModelInfos.ForEach(i =>
{
var eventsRemaining = query.ExpectedNumberOfEvents - eventsProcessed;
infos.Attach(i);
i.LastUpdated = now;
i.CurrentAsOfEventId = storedEvent.Id;
i.LatencyInMilliseconds = (now - @event.Timestamp).TotalMilliseconds;
i.BatchRemainingEvents = eventsRemaining;
if (eventsProcessed == 1)
{
i.BatchStartTime = now;
i.BatchTotalEvents = query.ExpectedNumberOfEvents;
}
if (i.InitialCatchupStartTime == null)
{
i.InitialCatchupStartTime = now;
i.InitialCatchupEvents = query.ExpectedNumberOfEvents;
}
if (eventsRemaining == 0 & i.InitialCatchupEndTime == null)
{
i.InitialCatchupEndTime = now;
}
});
work.VoteCommit();
}
}
else
{
throw new SerializationException(string.Format(
"Deserialization: Event type '{0}.{1}' not found",
storedEvent.StreamName,
storedEvent.Type));
}
}
catch (Exception ex)
{
var error = @event == null
? SerializationError(ex, storedEvent)
: new Domain.EventHandlingError(ex, @event: @event);
ReadModelUpdate.ReportFailure(
error,
() => CreateReadModelDbContext());
}
var status = new ReadModelCatchupStatus
{
BatchCount = query.ExpectedNumberOfEvents,
NumberOfEventsProcessed = eventsProcessed,
CurrentEventId = storedEvent.Id,
EventTimestamp = storedEvent.Timestamp,
StatusTimeStamp = now,
CatchupName = Name
};
if (status.IsEndOfBatch)
{
// reset the re-entrancy flag
running = 0;
query.Dispose();
}
ReportStatus(status);
}
return(eventsProcessed);
}