Is there a way programatically to find out if the SCOM agent is in Maintenance Mode.
This could be done by calling cmdlets.
Add-PSSnapin Microsoft.EnterpriseManagement.OperationsManager.Client
Get-Agent
Add Reference to
System.Management.Automation.dll
public class ExecuteCmdlet
{
public static InitialSessionState state;
public static RunspacePool pool;
static ExecuteCmdlet()
{
Console.WriteLine("Creating Initial State");
state = InitialSessionState.CreateDefault();
try
{
PSSnapInException ex = null;
state.ImportPSSnapIn("Microsoft.EnterpriseManagement.OperationsManager.Client", out ex);
}
catch { }
pool = RunspaceFactory.CreateRunspacePool(state);
pool.SetMinRunspaces(3);
pool.SetMaxRunspaces(10);
pool.Open();
}
public static Collection<PSObject> Execute(string cmd)
{
PowerShell gpc = PowerShell.Create();
// Specify the runspace to use and add commands.
gpc.RunspacePool = pool;
gpc.AddCommand(cmd);
return gpc.Invoke();
}
}
Related
I have a Blazor server app. Some variables on a specific razor page (main.razor) are defined as static because I want that these variables keep their values when the client navigates to other pages in the same project and comes back again to main.razor. So far it is working good.
But when I refresh the complete page, or even close the tab and reopen my app (login again), I see that the static variables still keep their values. How can prevent this? Of course I want that the values return to their default values (like 0 or ""), when the client makes a login or refreshes the page with F5. How can I do that?
I have defined the related variables in the following way:
private static StringBuilder log = new StringBuilder();
public static string testvar1= "";
public static int testvar2= 0;
Statics exist for the lifetime of the application instance which explains the behaviour you see.
You need to be maintaining state. At one end of the spectrum you can implement a State Management system such as Fluxor. At the other just create a user class, set it up as a service and inject it as a Scoped Service. Or you can build a middle-of-the-road solution.
This is mine.
A generic UIStateService that maintains a Dictionary of (state)objects against a Guid.
public class UIStateService
{
private Dictionary<Guid, object> _stateItems = new Dictionary<Guid, object>();
public void AddStateData(Guid Id, object value)
{
if (_stateItems.ContainsKey(Id))
_stateItems[Id] = value;
else
_stateItems.Add(Id, value);
}
public void ClearStateData(Guid Id)
{
if (_stateItems.ContainsKey(Id))
_stateItems.Remove(Id);
}
public bool TryGetStateData<T>(Guid Id, out T? value)
{
value = default;
if (Id == Guid.Empty)
return false;
var isdata = _stateItems.ContainsKey(Id);
var val = isdata
? _stateItems[Id]
: default;
if (val is T)
{
value = (T)val;
return true;
}
return false;
}
}
Set it up as a service:
builder.Services.AddScoped<UIStateService>();
Next define a simple template ComponentBase page that contains the common page code:
using Blazr.UI;
using Microsoft.AspNetCore.Components;
namespace BlazorApp2.Pages
{
public class StatePage : ComponentBase
{
// this provides a guid for this specific page during the lifetime of the application runtime
// we use this as the reference to store the state data against
private static Guid RouteId = Guid.NewGuid();
[Inject] protected UIStateService UIStateService { get; set; } = default!;
protected void SaveState<T>(T state) where T : class, new()
{
if (RouteId != Guid.Empty)
this.UIStateService.AddStateData(RouteId, state);
}
protected bool GetState<T>( out T value) where T : class, new()
{
value = new T();
if (RouteId != Guid.Empty && this.UIStateService.TryGetStateData<T>(RouteId, out T? returnedState))
{
value = returnedState ?? new T();
return true;
}
else
return false;
}
}
}
And use it in a page:
#page "/"
#inherits StatePage
<PageTitle>Index</PageTitle>
<h1>Hello, world!</h1>
Welcome to your new app.
<SurveyPrompt Title="How is Blazor working for you?" />
<div class="p-2">
<button class="btn btn-primary" #onclick=SetData>Set Data</button>
</div>
<div class="p-3 text-primary">
State Time : #stateData.StateTime;
</div>
#code {
private MyStateData stateData = new MyStateData();
protected override void OnInitialized()
{
if (this.GetState<MyStateData>(out MyStateData value))
this.stateData = value;
else
this.SaveState<MyStateData>(this.stateData);
}
private void SetData()
{
this.stateData.StateTime = DateTime.Now.ToLongTimeString();
SaveState<MyStateData>(this.stateData);
}
public class MyStateData
{
public string StateTime { get; set; } = DateTime.Now.ToLongTimeString();
}
}
You can now navigate around the application and the state will be maintained for the page.
You can apply an observer/notification pattern to the state object to trigger automatic state updates if you wish.
I'm using MySQL with EF Core. I am currently using Pomelo Provider for MySQL. I need to implement Unit Of Work Pattern for transactions. I have a Service which calls two methods in repository. I am not able to implement nested transactions. This is how my method in service looks now:
public void methodA(param)
{
using (TransactionScope tx = new
TransactionScope(TransactionScopeOption.Required))
{
repo1.save(data1);
repo2.save(data2);
tx.complete();
}
}
This is how save method in repo1 is implemented
private readonly UserDbContext appDbContext;
public repo1(UserDbContext _appDbContext)
{
appDbContext = _appDbContext;
}
public void save(User entity)
{
var dbset = appDbContext.Set<User>().Add(entity);
appDbContext.SaveChanges();
}
This is how save method in repo2 is implemented
private readonly UserDbContext appDbContext;
public repo2(UserDbContext _appDbContext)
{
appDbContext = _appDbContext;
}
public void save(UserRole entity)
{
var dbset = appDbContext.Set<UserRole>().Add(entity);
appDbContext.SaveChanges();
}
I am getting the following error while running method in service:
Error generated for warning 'Microsoft.EntityFrameworkCore.Database.Transaction.AmbientTransactionWarning: An ambient transaction has been detected. The current provider does not support ambient transactions. See http://go.microsoft.com/fwlink/?LinkId=800142'. This exception can be suppressed or logged by passing event ID 'RelationalEventId.AmbientTransactionWarning' to the 'ConfigureWarnings' method in 'DbContext.OnConfiguring' or 'AddDbContext'.
This is how I registered UserDbContext in Startup.cs
services.AddDbContext<UserDbContext>(options => options.UseLazyLoadingProxies().UseMySql("Server = xxxx; Database = xxx; Uid = xx;ConnectionReset=True;", b => b.MigrationsAssembly("AssemblyName")));
I even tried adding a middleware which starts transaction at the begining of request and commits/rollbacks during the response . But still I am not able to manage nested transactions.
This is how my middleware looks:
public class TransactionPerRequestMiddleware
{
private readonly RequestDelegate next_;
public TransactionPerRequestMiddleware(RequestDelegate next)
{
next_ = next;
}
public async Task Invoke(HttpContext context, UserDbContext
userDbContext)
{
var transaction = userDbContext.Database.BeginTransaction(
System.Data.IsolationLevel.ReadCommitted);
await next_.Invoke(context);
int statusCode = context.Response.StatusCode;
if (statusCode == 200 || statusCode==302)
{
transaction.Commit();
}
else
{
transaction.Rollback();
}
}
}
Can anyone help me please?
I have an Azure WebJob that will be used for Staging and Production. The keys for the proper environments are set in the app.config file.
A ConfigManager class reads the properties from the app.config file.
public static string FirstQueue
{
get { return ConfigurationManager.AppSettings["FirstQueue"]; }
}
I would like the QueueTrigger to read the from the proper queue specified in the app.config file.
public static void ProcessFirstQueue([QueueTrigger(ConfigManager.FirstQueue)] string message)
{
//some function
}
However, the QueueTrigger doesn't seem to like this. I get "An attribute argument must be a constant expression, type of expression...." Any suggestions to set this up. I do not want to hard code values in the queue trigger.
Thanks
You can resolve the queue name at runtime using the
INameResolver
Here's an example to demonstrate this:
WebJob Code:
public class Program
{
private static void Main(string[] args)
{
var config =
new JobHostConfiguration("insert connection string")
{
NameResolver = new QueueNameResolver()
};
var host = new JobHost(config);
host.RunAndBlock();
}
public static void ProcessNotification([QueueTrigger("%queueKey%")] string item)
{
//Handle message
}
public static void ProcessPoison([QueueTrigger("%queueKeyPoison%")] string item)
{
//Handle poison message
}
}
Here's the QueueNameResolver class:
public class QueueNameResolver : INameResolver
{
//name = queueKey or queueKeyPoison
public string Resolve(string name)
{
//Use the name to get it from the app.config or somewhere else.
}
}
Hope this helps,
I have wcf library with service contracts and implementations.
[ServiceContract]
public interface IServiceProtoType
{
[OperationContract]
Response GetMessage(Request request);
[OperationContract]
String SayHello();
}
[DataContract]
public class Request
{
private string name;
[DataMember]
public string Name
{
get { return name; }
set { name = value; }
}
}
[DataContract]
public class Response
{
private string message;
[DataMember]
public string Message
{
get { return message; }
set { message = value; }
}
}
public class MyDemoService : IServiceProtoType
{
public Response GetMessage(Request request)
{
var response = new Response();
if (null == request)
{
response.Message = "Error!";
}
else
{
response.Message = "Hello, " + request.Name;
}
return response;
}
public string SayHello()
{
return "Hello, World!";
}
}
I have windows service project that references this library, where MyService is just an empty shell that inherits ServiceBase. This service is installed and running under local system.
static void Main()
{
ServiceBase.Run(CreateContainer().Resolve());
}
private static IWindsorContainer CreateContainer()
{
IWindsorContainer container = new WindsorContainer();
container.Install(FromAssembly.This());
return container;
}
public class ServiceInstaller : IWindsorInstaller
{
#region IWindsorInstaller Members
public void Install(IWindsorContainer container, Castle.MicroKernel.SubSystems.Configuration.IConfigurationStore store)
{
string myDir;
if (string.IsNullOrEmpty(AppDomain.CurrentDomain.RelativeSearchPath))
{
myDir = AppDomain.CurrentDomain.BaseDirectory;
}
else
{
myDir = AppDomain.CurrentDomain.RelativeSearchPath;
}
var wcfLibPath = Path.Combine(myDir , "WcfDemo.dll");
string baseUrl = "http://localhost:8731/DemoService/{0}";
AssemblyName myAssembly = AssemblyName.GetAssemblyName(wcfLibPath);
container
.Register(
AllTypes
.FromAssemblyNamed(myAssembly.Name)
.InSameNamespaceAs<WcfDemo.MyDemoService>()
.WithServiceDefaultInterfaces()
.Configure(c =>
c.Named(c.Implementation.Name)
.AsWcfService(
new DefaultServiceModel()
.AddEndpoints(WcfEndpoint
.BoundTo(new WSHttpBinding())
.At(string.Format(baseUrl,
c.Implementation.Name)
)))), Component.For<ServiceBase>().ImplementedBy<MyService>());
}
#endregion
}
In Client Console app I have the following code and I am getting the following error:
{"Sequence contains no elements"}
static void Main(string[] args)
{
IWindsorContainer container = new WindsorContainer();
string baseUrl = "http://localhost:8731/DemoService/{0}";
container.AddFacility<WcfFacility>(f => f.CloseTimeout = TimeSpan.Zero);
container
.Register(
Types
.FromAssemblyContaining<IServiceProtoType>()
.InSameNamespaceAs<IServiceProtoType>()
.Configure(
c => c.Named(c.Implementation.Name)
.AsWcfClient(new DefaultClientModel
{
Endpoint = WcfEndpoint
.BoundTo(new WSHttpBinding())
.At(string.Format(baseUrl,
c.Name.Substring(1)))
})));
var service1 = container.Resolve<IServiceProtoType>();
Console.WriteLine(service1.SayHello());
Console.ReadLine();
}
I have an idea what this may be but you can stop reading this now (and I apologize for wasting your time in advance) if the answer to the following is no:
Is one (or more) of Request, Response, or MyDemoService in the same namespace as IServiceProtoType?
I suspect that Windsor is getting confused about those, since you are doing...
Types
.FromAssemblyContaining<IServiceProtoType>()
.InSameNamespaceAs<IServiceProtoType>()
... and then configuring everything which that returns as a WCF client proxy. This means that it will be trying to create proxies for things that should not be and hence a Sequence Contains no Elements exception (not the most useful message IMHO but crushing on).
The simple fix would be just to put your IServiceProtoType into its own namespace (I often have a namespace like XXXX.Services for my service contracts).
If that is not acceptable to you then you need to work out another way to identify just the service contracts - take a look at the If method for example or just a good ol' Component.For perhaps.
I'm using Castle Windsor 2.5.3 in an ASP.NET 4.0 Web Application (not ASP.NET MVC)
I have an interceptor which is being used to intercept calls to a data access component. The interceptor depends on a cache manager. The cache manager is used by the interceptor to avoid calling the data access component if the cache manager has the required data.
Even though the cache manager is registered as a Singleton, it is being instantiated multiple times. I can prove this with a debug message or a hit-count breakpoint in its default constructor.
A new requirement is for the cache to be clearable on demand, so I thought it would be a simple matter of resolving the Cache Manager and calling EmptyCache. What is happening is that the container is creating a new instance of the Cache Manager on which the call to EmptyCache has no effect (since the new cache manager has no cached data). Here is the code in the web page for clearing the cache:
protected void flushButton_Click(object sender, EventArgs e)
{
ICacheManager cacheManager = null;
try
{
cacheManager = Global.Container.Resolve<ICacheManager>();
cacheManager.EmptyCache();
resultLabel.Text = "Cache has been flushed";
}
catch (Exception ex)
{
resultLabel.Text = "An error occurred. The reason given was: " + ex.Message;
}
finally
{
if (cacheManager != null)
Global.Container.Release(cacheManager);
}
}
When I hover over the Container in Visual Studio and drill into the Components, the CacheManager is marked as Singleton. How can this be happening?
My Cache Manager is registered like this:
public class WindsorComponentInstaller : IWindsorInstaller
{
public void Install(IWindsorContainer container, IConfigurationStore store)
{
container.Register(
Component.For(typeof(Data.Common.Cache.ICacheManager))
.ImplementedBy(typeof(Data.Common.Cache.CacheManager))
.LifeStyle.Singleton
);
container.Register(
Component.For<Data.Common.CachingInterceptor>()
);
}
}
The Cache Manager interface looks like this:
public interface ICacheManager
{
object CacheItem(string cacheKey, DateTime absoluteExpiration, CacheItemPriority priority, Func<object> itemProvider);
object CacheItem(string cacheKey, TimeSpan slidingExpiration, CacheItemPriority priority, Func<object> itemProvider);
void EmptyCache();
}
The interceptor looks like this:
public class CachingInterceptor : IInterceptor
{
private ILogger logger = NullLogger.Instance;
private ICacheManager cacheManager;
public CachingInterceptor(ICacheManager cacheManager)
{
this.cacheManager = cacheManager;
}
public ILogger Logger
{
set
{
if (value != null) logger = value;
}
}
public void Intercept(IInvocation invocation)
{
try
{
string cacheItemKey = MakeCacheItemKey(invocation);
//Debug.WriteLine("Cache Key: {0}", cacheItemKey);
TimeSpan lifespan = TimeSpan.Parse("00:20:00");
bool cacheHit = true;
object result = cacheManager.CacheItem(cacheItemKey, lifespan, CacheItemPriority.Low,
() =>
{
invocation.Proceed();
//Debug.WriteLine(String.Format("populate-the-cache callback was invoked and returned a {0}", invocation.ReturnValue ?? "null"));
cacheHit = false;
return invocation.ReturnValue;
}
);
logger.DebugFormat("Interceptor {0} Cache Hit: {1}", (invocation.Method.Name ?? "null"), cacheHit.ToString());
invocation.ReturnValue = result;
}
catch (Exception ex)
{
logger.Error("Intercept Error", ex);
}
}
private string MakeCacheItemKey(IInvocation invocation)
{
StringBuilder sb = new StringBuilder();
sb.Append(invocation.InvocationTarget);
sb.Append("|" + invocation.MethodInvocationTarget.Name);
sb.Append("|" + invocation.MethodInvocationTarget.ReturnType);
foreach (ParameterInfo pi in invocation.MethodInvocationTarget.GetParameters())
sb.Append("|" + pi.ParameterType.ToString());
foreach (var arg in invocation.Arguments)
{
sb.Append("|");
sb.Append(arg ?? "null");
}
return sb.ToString();
}
}
The data components are registered like this:
public void Install(IWindsorContainer container, IConfigurationStore store)
{
string connStr = ConfigurationManager.ConnectionStrings["Database"].ConnectionString;
container.Register(
Component.For<IActualCostsVersusBudgetDataProvider>()
.ImplementedBy<ActualCostsVersusBudgetDataProvider>()
.DependsOn(Property.ForKey("connectionString").Eq(connStr))
.LifeStyle.Transient
.Interceptors(InterceptorReference.ForType<CachingInterceptor>())
.Anywhere
);
/* Many calls to .Register omitted */
}
The business objects that depend on data providers are registered like this:
public void Install(IWindsorContainer container, IConfigurationStore store)
{
container.Register(
AllTypes.FromThisAssembly()
.Where(t => t.Name.EndsWith("Manager"))
.Configure(c => c.LifeStyle.Transient)
);
}
The container is initialized like this in global.asax:
public static IWindsorContainer Container { get; private set; }
public Global()
{
Container = BootstrapContainer();
}
private IWindsorContainer BootstrapContainer()
{
WindsorContainer container = new WindsorContainer();
container.AddFacility<LoggingFacility>(f => f.LogUsing(LoggerImplementation.Log4net).WithAppConfig());
container.Install(
new Data.Common.Installers.WindsorComponentInstaller(),
new Data.Installers.WindsorComponentInstaller(),
new Business.Installers.WindsorComponentInstaller()
);
return container;
}