How can I utilize the Trace on a PersistenConnection?
public class Connection : PersistentConnection
{
protected override Task OnConnectedAsync(IRequest request, string connectionId)
{
Trace.TraceInformation("ConnectedAsync ConnectionId:{0}", connectionId);
return base.OnConnectedAsync(request, connectionId);
}
}
How do I attach a Trace listener so the information in the TraceInformation call becomes visible?
To turn on everything:
using Microsoft.AspNet.SignalR.Tracing;
public StockTickerHub(StockTicker stockTicker)
{
_stockTicker = stockTicker;
ITraceManager traceManager = GlobalHost.DependencyResolver.Resolve<ITraceManager>();
traceManager.Switch.Level = SourceLevels.All;
}
Related
Is it possible to establish some mechanism so that in case the insertion of the audit fails in the default dataprovider, oracle for example, another data provider is used, for example in a file?
Thanks for the help
There is not a data provider with automatic fallback capabilities, but you can implement a custom data provider.
Say you want the Sql data provider by default, and another data provider as fallback. Inherit from the SQL data provider (SqlDataProvider) and fallback to another DataProvider when a SqlException is thrown:
public class FallbackSqlDataProvider : SqlDataProvider
{
public AuditDataProvider FallbackProvider { get; set; }
public override object InsertEvent(AuditEvent auditEvent)
{
try
{
return base.InsertEvent(auditEvent);
}
catch (SqlException)
{
return FallbackProvider?.InsertEvent(auditEvent);
}
}
public override async Task<object> InsertEventAsync(AuditEvent auditEvent)
{
try
{
return await base.InsertEventAsync(auditEvent);
}
catch (SqlException)
{
return await FallbackProvider?.InsertEventAsync(auditEvent);
}
}
public override void ReplaceEvent(object eventId, AuditEvent auditEvent)
{
try
{
base.ReplaceEvent(eventId, auditEvent);
}
catch (SqlException)
{
FallbackProvider?.ReplaceEvent(eventId, auditEvent);
}
}
public override async Task ReplaceEventAsync(object eventId, AuditEvent auditEvent)
{
try
{
await base.ReplaceEventAsync(eventId, auditEvent);
}
catch (SqlException)
{
await FallbackProvider?.ReplaceEventAsync(eventId, auditEvent);
}
}
}
Then you can set the fallback data provider on FallbackProvider property, for example like this:
var dp = new FallbackSqlDataProvider()
{
ConnectionString = "cnnstring",
TableName = "table",
IdColumnName = "id",
JsonColumnName = "data",
FallbackProvider = new Log4netDataProvider()
{
Logger = LogManager.GetLogger(typeof(Log4netDataProvider)),
LogMessageBuilder = (ev, id) => ev.ToJson()
}
};
Audit.Core.Configuration.Setup()
.UseCustomProvider(dp);
Also check this related issue.
I am building a general spring-kafka configuration for teams to use in their projects.
I would like to define a general custom error handler at container level, and allow the project to define a listener error handler for each listener. Anything that is not handled by the listener error handler should fall back to the container.
From what i've tested so far it's either one or the other. any way to get them to work together?
Would it make sense to have a handler chain at container level and allow projects to add error handlers to the chain?
There is nothing to prevent you configuring both error handlers...
#SpringBootApplication
public class So55001718Application {
public static void main(String[] args) {
SpringApplication.run(So55001718Application.class, args);
}
#KafkaListener(id = "so55001718", topics = "so55001718", errorHandler = "listenerEH")
public void listen(String in) {
System.out.println(in);
if ("bad1".equals(in)) {
throw new IllegalStateException();
}
else if("bad2".equals(in)) {
throw new IllegalArgumentException();
}
}
#Bean
public KafkaListenerErrorHandler listenerEH() {
return (m, t) -> {
if (t.getCause() instanceof IllegalStateException) {
System.out.println(
t.getClass().getSimpleName() + " bad record " + m.getPayload() + " handled by listener EH");
return null;
}
else {
throw (t);
}
};
}
#Bean
public ConcurrentKafkaListenerContainerFactory<?, ?> kafkaListenerContainerFactory(
ConcurrentKafkaListenerContainerFactoryConfigurer configurer,
ConsumerFactory<Object, Object> kafkaConsumerFactory) {
ConcurrentKafkaListenerContainerFactory<Object, Object> factory = new ConcurrentKafkaListenerContainerFactory<>();
configurer.configure(factory, kafkaConsumerFactory);
factory.setErrorHandler((t, r) -> {
System.out.println(t.getClass().getSimpleName() + " bad record " + r.value() + " handled by container EH");
});
return factory;
}
#Bean
public NewTopic topic() {
return new NewTopic("so55001718", 1, (short) 1);
}
#Bean
public ApplicationRunner runner(KafkaTemplate<String, String> template) {
return args -> {
template.send("so55001718", "good");
template.send("so55001718", "bad1");
template.send("so55001718", "bad2");
};
}
}
and
good
bad1
ListenerExecutionFailedException bad record bad1 handled by listener EH
bad2
ListenerExecutionFailedException bad record bad2 handled by container EH
You can create a simple wrapper to wrap multiple error handlers; feel free to open a GitHub issue (contributions are welcome).
I have the following code...
#Controller
#RequestMapping("/stomp/**")
public class StompController {
#MessageMapping("/hello")
#SendTo("/topic/greet")
public Greeting greet(HelloMessage message) throws Exception{
System.out.println("Inside the method "+message.getName());
Thread.sleep(3000);
return new Greeting("Hello, "+message.getName()+"!");
}
}
#Configuration
#EnableWebSocketMessageBroker
public class WebSocketConfig extends AbstractWebSocketMessageBrokerConfigurer {
#Override
public void configureMessageBroker(MessageBrokerRegistry config) {
config.enableSimpleBroker("/stomp/topic");
config.setApplicationDestinationPrefixes("/app");
}
#Override
public void registerStompEndpoints(StompEndpointRegistry registry) {
registry.addEndpoint("/stomp/hello").withSockJS();
}
}
<script type="text/javascript">
var stompClient = null;
function setConnected(connected) {
document.getElementById('connect').disabled = connected;
document.getElementById('disconnect').disabled = !connected;
document.getElementById('conversationDiv').style.visibility = connected ? 'visible' : 'hidden';
document.getElementById('response').innerHTML = '';
}
function connect() {
var socket = new SockJS('/stomp/hello');
stompClient = Stomp.over(socket);
stompClient.connect({}, function(frame) {
setConnected(true);
console.log('Connected: ' + frame);
stompClient.subscribe('/stomp/topic/greet', function(greeting){
showGreeting(JSON.parse(greeting.body).content);
});
});
}
function disconnect() {
stompClient.disconnect();
setConnected(false);
console.log("Disconnected");
}
function sendName() {
var name = document.getElementById('name').value;
stompClient.send("/stomp/app/hello", {}, JSON.stringify({ 'name': name }));
}
function showGreeting(message) {
var response = document.getElementById('response');
var p = document.createElement('p');
p.style.wordWrap = 'break-word';
p.appendChild(document.createTextNode(message));
response.appendChild(p);
}
</script>
The Client side code seems to connect fine but I don't see the console message meaning to me "/stomp/app/hello" is the wrong path. What should the proper path be?
I also tried /app/stomp/hello no dice...
Update
I can remove the #RequestMapping("/stomp/**") and remove the stomp related stuff and it works fine for my simple test, however, I need it to work for a more complex application that will not allow this.
#RequestMapping and #MessageMapping annotations can be used in similar ways, but are totally different.
#MessageMapping can also be used at the type level (see reference documentation), so you could annotate your controller with #MessageMapping("/stomp/**").
Nothing prevents you from annotating a Controller with both #MessageMapping and #RequestMapping - similar programming model, different purposes.
Using VS2012/.NET 4.5 I am creating a custom activity which implements a Receive child activity (as an implementation child). The parameters are in the example below fixed to just one: OutValue of type Guid.
I really would love to access the value of incoming parameter value in ReceiveDone, because I need to work with it and transform it before returning it from the activity. Please ignore that I am currently using a Guid, it still fails to access the value with and InvalidOperationException:
An Activity can only get the location of arguments which it owns. Activity 'TestActivity' is trying to get the location of argument 'OutValue' which is owned by activity 'Wait for
workflow start request [Internal for TestActivity]'
I have tried everything I could think of, but am stupefied. There must be a way to do this very simple thing?
public class TestActivity : NativeActivity<Guid>
{
protected override void CacheMetadata(NativeActivityMetadata metadata)
{
var content = ReceiveParametersContent.Create(new Dictionary<string, OutArgument>()
{
// How to access the runtime value of this inside TestActivity?
{"OutValue", new OutArgument<Guid>()}
});
startReceiver = new Receive()
{
DisplayName = string.Format("Wait for workflow start request [Internal for {0}]", this.DisplayName),
CanCreateInstance = true,
ServiceContractName = XName.Get("IStartService", Namespace),
OperationName = "Start",
Content = content
};
foreach (KeyValuePair<string, OutArgument> keyValuePair in content.Parameters)
{
metadata.AddImportedChild(keyValuePair.Value.Expression);
}
metadata.AddImplementationChild(startReceiver);
}
protected override void Execute(NativeActivityContext context)
{
context.ScheduleActivity(startReceiver, ReceiveDone);
}
private void ReceiveDone(NativeActivityContext context, ActivityInstance completedInstance)
{
var receive = completedInstance.Activity as Receive;
ReceiveParametersContent content = receive.Content as ReceiveParametersContent;
try
{
// This causes InvalidOperationException.
// An Activity can only get the location of arguments which it owns.
// Activity 'TestActivity' is trying to get the location of argument 'OutValue'
// which is owned by activity 'Wait for workflow start request [Internal for TestActivity]'
var parmValue = content.Parameters["OutValue"].Get(context);
}
catch (Exception)
{ }
}
private Receive startReceiver;
private const string Namespace = "http://company.namespace";
}
Use internal variables to pass values between internal activities.
Although not directly related to your code, see the example below which should give you the idea:
public sealed class CustomNativeActivity : NativeActivity<int>
{
private Variable<int> internalVar;
private Assign<int> internalAssign;
protected override void CacheMetadata(NativeActivityMetadata metadata)
{
base.CacheMetadata(metadata);
internalVar = new Variable<int>("intInternalVar", 10);
metadata.AddImplementationVariable(internalVar);
internalAssign = new Assign<int>
{
To = internalVar,
Value = 12345
};
metadata.AddImplementationChild(internalAssign);
}
protected override void Execute(NativeActivityContext context)
{
context.ScheduleActivity(internalAssign, (activityContext, instance) =>
{
// Use internalVar value, which was seted by previous activity
var value = internalVar.Get(activityContext);
Result.Set(activityContext, value);
});
}
}
Calling the above activity:
WorkflowInvoker.Invoke<int>(new CustomNativeActivity());
Will output:
12345
Edit:
In your case your OutArgument will be the internalVar
new OutArgument<int>(internalVar);
You need to use OutArgument and them to variables. See the code example with the documentation.
I may have tried everything I thought of, but I am stubborn and refuse to give up, so I kept on thinking ;)
I here have changed my example to use a Data class as a parameter instead (it does not change anything in itself, but I needed that in my real world example).
This code below is now a working example on how to access the incoming data. The use of an implementation Variable is the key:
runtimeVariable = new Variable<Data>();
metadata.AddImplementationVariable(runtimeVariable);
And the OutArgument:
new OutArgument<Data>(runtimeVariable)
I can then access the value with:
// Here dataValue will get the incoming value.
var dataValue = runtimeVariable.Get(context);
I haven't seen an example elsewhere, which does exactly this. Hope it will be of use to any one but me.
The code:
[DataContract]
public class Data
{
[DataMember]
Guid Property1 { get; set; }
[DataMember]
int Property2 { get; set; }
}
public class TestActivity : NativeActivity<Guid>
{
public ReceiveContent Content { get; set; }
protected override void CacheMetadata(NativeActivityMetadata metadata)
{
runtimeVariable = new Variable<Data>();
metadata.AddImplementationVariable(runtimeVariable);
Content = ReceiveParametersContent.Create(new Dictionary<string, OutArgument>()
{
{"OutValue", new OutArgument<Data> (runtimeVariable)}
});
startReceiver = new Receive()
{
DisplayName = string.Format("Wait for workflow start request [Internal for {0}]", this.DisplayName),
CanCreateInstance = true,
ServiceContractName = XName.Get("IStartService", Namespace),
OperationName = "Start",
Content = Content
};
metadata.AddImplementationChild(startReceiver);
}
protected override void Execute(NativeActivityContext context)
{
context.ScheduleActivity(startReceiver, ReceiveDone);
}
private void ReceiveDone(NativeActivityContext context, ActivityInstance completedInstance)
{
// Here dataValue will get the incoming value.
var dataValue = runtimeVariable.Get(context);
}
private Receive startReceiver;
private Variable<Data> runtimeVariable;
private const string Namespace = "http://company.namespace";
}
In Martin Fowler's "Patterns of Enterprise Application Architecture"
is described approach for organizing DAL like a set of mappers for entities. Each has it's own IdentityMap storing specific entity.
for example in my ASP.NET WebApplication:
//AbstractMapper - superclass for all mappers in DAL
public abstract class AbstractMapper
{
private readonly string _connectionString;
protected string ConnectionString
{
get { return _connectionString; }
}
private readonly DbProviderFactory _dbFactory;
protected DbProviderFactory DBFactory
{
get { return _dbFactory; }
}
#region LoadedObjects (IdentityMap)
protected Hashtable LoadedObjects = new Hashtable();
public void RegisterObject(long id, DomainObject obj)
{
LoadedObjects[id] = obj;
}
public void UnregisterObject(long id)
{
LoadedObjects.Remove(id);
}
#endregion
public AbstractMapper(string connectionString, DbProviderFactory dbFactory)
{
_connectionString = connectionString;
_dbFactory = dbFactory;
}
protected virtual string DBTable
{
get
{
throw new NotImplementedException("database table is not defined in class " + this.GetType());
}
}
protected virtual T Find<T>(long id, IDbTransaction tr = null) where T : DomainObject
{
if (id == 0)
return null;
T result = (T)LoadedObjects[id];
if (result != null)
return result;
IDbConnection cn = GetConnection(tr);
IDbCommand cmd = CreateCommand(GetFindStatement(id), cn, tr);
IDataReader rs = null;
try
{
OpenConnection(cn, tr);
rs = cmd.ExecuteReader(CommandBehavior.SingleRow);
result = (rs.Read()) ? Load<T>(rs) : null;
}
catch (DbException ex)
{
throw new DALException("Error while loading an object by id in class " + this.GetType(), ex);
}
finally
{
CleanUpDBResources(cmd, cn, tr, rs);
}
return result;
}
protected virtual T Load<T>(IDataReader rs) where T : DomainObject
{
long id = GetReaderLong(rs["ID"]);
T result = (T)LoadedObjects[id];
if (result != null)
return result;
result = (T)DoLoad(id, rs);
RegisterObject(id, result);
return result;
}
// another CRUD here ...
}
// Specific Mapper for entity Account
public class AccountMapper : AbstractMapper
{
internal override string DBTable
{
get { return "Account"; }
}
public AccountMapper(string connectionString, DbProviderFactory dbFactory) : base(connectionString, dbFactory) { }
public Account Find(long id)
{
return Find<Account>(id);
}
public override DomainObject DoLoad(long id, IDataReader rs)
{
Account account = new Account(id);
account.Name = GetReaderString(rs["Name"]);
account.Value = GetReaderDecimal(rs["Value"]);
account.CurrencyID = GetReaderLong(rs["CurrencyID"]);
return account;
}
// ...
}
The question is: where to store these mappers? How system services (entities) should call mappers?
I decided to create MapperRegistry containing all mappers. So services can call mappers like:
public class AccountService : DomainService
{
public static Account FindAccount(long accountID)
{
if (accountID > 0)
return MapperRegistry.AccountMapper.Find(accountID);
return null;
}
...
}
But where can I store MapperRegistry instance? I see following variants, but don't like any of them:
MapperRegistry is global for application (Singleton)
Not applicable because of necessity of synchronization in multi-thread ASP.NET application (at least Martin says that only mad can choose this variant)
MapperRegistry per Session
Seems not so good too. All ORMs (NHibernate, LINQ to SQL, EntityFramework) masters advise to use DataContext (NHibernateSession, ObjectContext) per Request and not to store context in Session.
Also in my WebApp almost all requests are AJAX-requests to EntityController.asmx (with attribute ScriptService) returning JSON. And session is not allowed.
MapperRegistry per Request
There are a lot of separate AJAX calls. In this case life cycle of MapperRegistry will be too small. So the data almost always will be retrieved from database, as a result - low performance.
Dear Experts, please help me with architectural solution.