FAQ - Health Monitoring in ASP.NET 2.0

  • Article

What is Health Monitoring?

Health Monitoring is a framework for monitoring status of running ASP.NET applications and logging significant ASP.NET application events.

 

Why would I use Health Monitoring?

  • Health Monitoring is runtime based for your production environment, so it provides information of your running ASP.NET applications
  • Health Monitoring gives event details rather than providing a number or a total, which can be useful to solve running application issues.
  • Health Monitoring is customizable, so you can tailor the event information they way you need it.

 

What are examples of Health Monitoring events that can be logged?

  • Application starts and stops
  • Failed logins and unhandled exceptions
  • "Heartbeats"
  • Successful and failed login attempts through Membership
  • Successful and failed URL and ACL authorizations by authenticated users
  • Valid and expired forms authentication tickets
  • View state validation failures
  • Compilation errors
  • Configuration errors
  • Unhandled exceptions
  • Request validation failures
  • Anything that causes request to abort
  • Requests queued, processing, or rejected
  • Specific or periodic monitoring event
  • Process start time and more

 

What are examples of locations where Health Monitoring events can be logged?

  • Windows event log
  • SQL Server database
  • Email
  • Console window using WMI
  • Trace output window

What are Health Monitoring events?

Health Monitoring events help you keep track of different things that are occurring while your ASP.NET application is running. These events are divided into five main areas:

  • Application Lifetime Events
  • All Audits
  • All Errors
  • Reqeust Processing Events
  • Heartbeats

What are Health Monitoring providers?

Providers consume Web event data. By default, the ASP.NET health-monitoring system can deliver Web event data using the built-in providers listed in the following table. More than one provider can listen for the same event, and more than one event can be consumed by the same provider.

 

Event Providers

Details

EventLogWebEventProvider

Writes Web event data to the Windows event log. By default, this provider is configured to write all errors to the Windows event log. Security operation errors are logged under the event name Failure Audits and logs all other errors are logged under the event name All Errors.

To read event log data, you can view data using the Windows Event Viewer or read event log data programmatically.

SqlWebEventProvider

Logs Web event data to a Microsoft SQL server database. By default, this provider logs data to the SQL Server Express database in the Web application's App_Data folder. It does not subscribe to any events by default.

WmiWebEventProvider

Passes Web events to WMI, converting them to WMI events. By default, this provider does not subscribe to any events.

To listen for WMI events, you can build an application such as the one illustrated in Walkthrough: Listening for WMI Events in ASP.NET Health Monitoring. For more information, see Using WMI to Deliver ASP.NET Health Monitoring Events. WMI applications do not have to be written in managed code.

SimpleMailWebEventProvider and TemplatedMailWebEventProvider

Sends an e-mail message when Web events are raised. By default, these providers are not configured and do not subscribe to any events.

TraceWebEventProvider

Passes event data to the ASP.NET page tracing system. By default, this provider is not configured and does not subscribe to any events. Tracing provides you the ability to start and stop event tracing sessions, to instrument applications to provide trace events, and to consume trace events. You can use the events to debug an application and perform capacity and performance analysis. For more information, see ASP.NET Tracing.

 

What are Health Monitoring profiles?

Profiles determine how events are collected by ASP.NET and raised to providers.

By default, there are two profiles named Critical and Default included in the configuration.

 

What are Health Monitoring buffers?

Buffers (BufferModes) define how health-monitoring events can be buffered before they are raised. The three included providers that can use bufferModes are:

  • SqlWebEventProvider (included by default)
  • SimpleMailWebEventProvider
  • TemplatedMailWebEventProvider

Each of the above providers inherits from the BufferedWebEventProvider class.

 

What are Health Monitoring rules?

The rules define the map of how an event is raised. At a minimum each rule must list the event name, the provider and the profile.

 

How is Health Monitoring configured and controlled?

The configuration is the main location to control what events will be monitored and how those events will be monitored. You can either modify the configuration using a text editor or use the API. For more information see, HealthMonitoringSection Class and ASP.NET Configuration Files.

 

Where in the configuration is Health Monitoring found?

The <healthMonitoring> section is within the <system.web> section of the configuration.

 

What are the sub-sections within the <healthMonitoring> section of the configuration?

There are five sub-sections within the <healthMonitoring> section. The Health Monitoring section looks like the following:

<healthMonitoring ...>

  <bufferModes>

    ...

  </bufferModes>

  <providers>

    ...

  </providers>

  <eventMappings>

    ...

  </eventMappings>

  <profiles>

    ...

  </profiles>

  <rules>

    ...

  </rules>

</healthMonitoring>

Are there default values (a default configuration) established in the <healthMonitoring> section of the configuration?

Yes. These values are contained at the root web.config file. The root web.config file is located at %windir%\Microsoft.NET\Framework\v2.0.50727\CONFIG. By default, a number of eventMappings, providers, profiles, rules, and bufferModes are already established within the <heathMonitoring> section.

 

What are the default Health Monitoring events included in the configuration?

The default events are mapped in the root web.config file:

<eventMappings>

  <add name="All Events" type="System.Web.Management.WebBaseEvent, ..." />

  <add name="HeartBeats"

    type="System.Web.Management.WebHeartBeatEvent, ..." />

  <add name="Application Lifetime Events"

    type="System.Web.Management.WebApplicationLifetimeEvent, ..." />

  <add name="Request Processing Events"

    type="System.Web.Management.WebRequestEvent, ..." />

  <add name="All Errors"

    type="System.Web.Management.WebBaseErrorEvent, ..." />

  <add name="Infrastructure Errors"

    type="System.Web.Management.WebErrorEvent, ..." />

  <add name="Request Processing Errors"

    type="System.Web.Management.WebRequestErrorEvent, ..." />

  <add name="All Audits" type="System.Web.Management.WebAuditEvent, ..." />

  <add name="Failure Audits"

    type="System.Web.Management.WebFailureAuditEvent, ..." />

  <add name="Success Audits"

    type="System.Web.Management.WebSuccessAuditEvent, ..." />

</eventMappings>

 

What are the default Health Monitoring providers included in the configuration?

The default providers are included in the following section of the root web.config file:

<providers>

    <add name="EventLogProvider"

            type="System.Web.Management.EventLogWebEventProvider, …

    <add name="SqlWebEventProvider"

            connectionStringName="LocalSqlServer"

            maxEventDetailsLength="1073741823"

            buffer="false"

            bufferMode="Notification"

            type="System.Web.Management.SqlWebEventProvider, …

    <add name="WmiWebEventProvider"

              type="System.Web.Management.WmiWebEventProvider,…

</providers>

 

What are the default Health Monitoring profiles included in the configuration?

The default profiles are included in the following section of the root web.config file:

<profiles>

    <add name="Default"

              minInstances="1"

          maxLimit="Infinite"

              minInterval="00:01:00"

              custom="" />

    <add name="Critical"

              minInstances="1"

              maxLimit="Infinite"

              minInterval="00:00:00"

              custom="" />

</profiles>

 

What are the default Health Monitoring buffers included in the configuration?

The default bufferModes are included in the following section of the root web.config file:

<bufferModes>

    <add name="Critical Notification"

         maxBufferSize="100"

  maxFlushSize="20"

         urgentFlushThreshold="1"

         regularFlushInterval="Infinite"

         urgentFlushInterval="00:01:00"

         maxBufferThreads="1" />

    <add name="Notification"

         …

    </>

    <add name="Analysis"

     …

    </>

    <add name="Logging“

         …

    </>

</bufferModes>

 

What are the default Health Monitoring rules included in the configuration?

The default rules are included in the following section of the root web.config file:

<rules>

  <add name="Failure Audits Default"

       eventName="Failure Audits"

       provider="EventLogProvider"

       profile="Default"

       minInterval="00:00:00"

       minInstances="1"

       maxLimit="Infinite"

  />

    ...

</rules>

 

I understand the basics of Health Monitoring, but I still don’t understand exactly how to implement it. How can I get started using Health Monitoring right now?

Follow the steps below:

1. Create a new Web application in Visual Web Developer.

2. From the Website menu select Add New Item.

3. Select and add a Web Configuration File.

4. Add the following node before the end of the <system.web> node in the newly added configuration file:

<healthMonitoring enabled="true" heartbeatInterval="10">

    <rules>

        <add name="Heartbeats Default"

             eventName="Heartbeats"

             provider="EventLogProvider"

             profile="Critical"/>

                        </rules>

</healthMonitoring>

5. Run your Web application.

6. Run the Event Viewer (eventvwr.exe).

7. Select Application in the right pane of the Event Viewer.

8. Notice that the “heartbeat” events for your application occur every 10 seconds.

 

What would be an example of using the SqlWebEventProvider to log monitoring event?

There is an example on the ASP.NET site that demonstrates the SqlWebEventProvider.

 

I understand that the root web.config file contains the default Health Monitoring support. What should I do if I want to modify the <healthMonitoring> section?

There are three points to note:

  • Use the Add, Remove, and Clear elements
  • Do not modify the root level config files
  • Modify using text editor or the API.

I understand that event friendly names are mapped to the event type within the configuration, but how can I find the exact events that are related to each friendly event name, such as “All Audits”?

Take a look at the WebEventCodes on MSDN. This list will give you a more specific list of events.

 

In the Event Viewer I see the event code (i.e. 1005) but how can I match that code to the specific event?

The list below will help you match the event code name with the event code number.

WebEventCode

Event Code

InvalidEventCode

-1

UndefinedEventCode

0

UndefinedEventDetailCode

0

ApplicationCodeBase

1000

ApplicationStart

1001

ApplicationShutdown

1002

ApplicationCompilationStart

1003

ApplicationCompilationEnd

1004

ApplicationHeartbeat

1005

RequestCodeBase

2000

RequestTransactionComplete

2001

RequestTransactionAbort

2002

ErrorCodeBase

3000

RuntimeErrorRequestAbort

3001

RuntimeErrorViewStateFailure

3002

RuntimeErrorValidationFailure

3003

RuntimeErrorPostTooLarge

3004

RuntimeErrorUnhandledException

3005

WebErrorParserError

3006

WebErrorCompilationError

3007

WebErrorConfigurationError

3008

WebErrorOtherError

3009

WebErrorPropertyDeserializationError

3010

WebErrorObjectStateFormatterDeserializationError

3011

AuditCodeBase

4000

AuditFormsAuthenticationSuccess

4001

AuditMembershipAuthenticationSuccess

4002

AuditUrlAuthorizationSuccess

4003

AuditFileAuthorizationSuccess

4004

AuditFormsAuthenticationFailure

4005

AuditMembershipAuthenticationFailure

4006

AuditUrlAuthorizationFailure

4007

AuditFileAuthorizationFailure

4008

AuditInvalidViewStateFailure

4009

AuditUnhandledSecurityException

4010

AuditUnhandledAccessException

4011

MiscCodeBase

6000

WebEventProviderInformation

6001

ApplicationDetailCodeBase

50000

ApplicationShutdownUnknown

50001

ApplicationShutdownHostingEnvironment

50002

ApplicationShutdownChangeInGlobalAsax

50003

ApplicationShutdownConfigurationChange

50004

ApplicationShutdownUnloadAppDomainCalled

50005

ApplicationShutdownChangeInSecurityPolicyFile

50006

ApplicationShutdownBinDirChangeOrDirectoryRename

50007

ApplicationShutdownBrowsersDirChangeOrDirectoryRename

50008

ApplicationShutdownCodeDirChangeOrDirectoryRename

50009

ApplicationShutdownResourcesDirChangeOrDirectoryRename

50010

ApplicationShutdownIdleTimeout

50011

ApplicationShutdownPhysicalApplicationPathChanged

50012

ApplicationShutdownHttpRuntimeClose

50013

ApplicationShutdownInitializationError

50014

ApplicationShutdownMaxRecompilationsReached

50015

StateServerConnectionError

50016

AuditDetailCodeBase

50200

InvalidTicketFailure

50201

ExpiredTicketFailure

50202

InvalidViewStateMac

50203

InvalidViewState

50204

WebEventDetailCodeBase

50300

SqlProviderEventsDropped

50301

WebExtendedBase

100000

 

What are the details that get logged when a Health Monitoring event occurs?

The WebBaseEvent provides the details of the information that gets logged for each event:

public class WebBaseEvent : System.Object

{

    public static WebApplicationInformation

                        ApplicationInformation { get; }

    public int EventCode { get; }

    public int EventDetailCode { get; }

    public Guid EventId { get; }

    public long EventOccurrence { get; }

    public long EventSequence { get; }

    public object EventSource { get; }

    public DateTime EventTime { get; }

    public DateTime EventTimeUtc { get; }

    public string Message { get; }

    public virtual void FormatCustomEventDetails (...);

    public virtual void Raise (...);

}

For more information, see WebBaseEvent Members.

 

How can I modify the configuration of another Web application using C# code?

Follow the steps below:

1. Create a Web application with the following name “aspnetexample”. Use C# and HTTP (localhost).

2. Now create a new C# console application. Add the following code to the console application:

// Add references:

// System.Configuration

// System.Web

#region Using directives

using System;

using System.Collections.Generic;

using System.Text;

using System.Configuration;

using System.Web;

using System.Web.Configuration;

#endregion

namespace HealthMonExample

{

    class UsingHealthMonitoringSection

    {

   static void Main(string[] args)

        {

            try

            {

                // Set the path of the config file.

                string configPath = "/aspnetexample";

                // Get the Web application configuration object.

       Configuration config = WebConfigurationManager.OpenWebConfiguration(configPath);

                // Get the section related object.

                HealthMonitoringSection configSection =

                  (HealthMonitoringSection)config.GetSection("system.web/healthMonitoring");

                // Display title and info.

                Console.WriteLine("ASP.NET Configuration Info");

                Console.WriteLine();

                // Display Config details.

                Console.WriteLine("File Path: {0}",

                  config.FilePath);

                Console.WriteLine("Section Path: {0}",

                  configSection.SectionInformation.Name);

                // Display Enabled property.

                Console.WriteLine("Enabled (old value): {0}",

                  configSection.Enabled.ToString());

                // Toggle the Enabled property.

                if (!configSection.Enabled)

                {

                    configSection.Enabled = true;

                }

  else

                {

                    configSection.Enabled = false;

                }

                // Display Providers Count.

                Console.WriteLine("Providers Count: {0}",

                  configSection.Providers.Count);

                // Display EventMappings Count.

                Console.WriteLine("EventMappings Count: {0}",

                  configSection.EventMappings.Count);

                // Display Profiles Count.

                Console.WriteLine("Profiles Count: {0}",

                  configSection.Profiles.Count);

                // Display Rules Count.

                Console.WriteLine("Rules Count: {0}",

                  configSection.Rules.Count);

                // Update if not locked.

           if (!configSection.SectionInformation.IsLocked)

                {

                    config.Save();

                    Console.WriteLine("** Configuration updated.");

                }

                else

                {

                    Console.WriteLine("** Could not update, section is locked.");

                }

            }

            catch (Exception e)

            {

                // Unknown error.

                Console.WriteLine(e.ToString());

            }

            // Display and wait

            Console.ReadLine();

        }

    }

}

3. Be sure to add the following references to your console application:
System.Configuration
System.Web

4. Run the console application. You’ll notice that Health Monitoring of your web application is enabled or disabled each time you run the console application.

Can the Health Monitoring subsystem be extended?

Yes, you can create your own providers, events and other objects to help customize the monitoring of your ASP.NET applications. For more information, see Web Event Providers and WebBaseEvent Class.

 

Where can I find out more about Health Monitoring and related topics?

ASP.NET Health Monitoring 

How to: Install and Configure SMTP Virtual Servers in IIS  

How to: Send E-mail for Health Monitoring Notifications

Web Event Providers (Custom Provider Example)

ASP.NET SQL Server Registration Tool

WebEventCodes Class

Walkthrough: Listening for WMI Events in ASP.NET Health Monitoring  

System.Web.Management Namespace