Windows Azure Event Logs Notifier

Introduction

Monitoring Azure application is no longer the developer's sole responsibility.
Many times the devOp is actually the one who is in charge on the stability and functionality of the cloud application.

The Windows Azure platform provides a great diagnostic mechanism called Windows Azure Diagnostics (check the following article on more info).

As you may know the azure application main components are the virtual machine that actually runs the code.

Lets go over Windows Azure Roles types very quickly:
We have the Web role which is the web site hosting the IIS server and the Worker role which execute tasks periodically.

Problem explained

As an operator of the application I would like to be notified immediately when an error occurs. Responding quickly is very crucial.
Once notified I can start debugging the application and identify the root cause.

The solution

I already know that Windows Azure Diagnostics can collect windows events from my role instances.
All I need to do is to analyze the data at specific sampling rate and send some sort of notification, preferably an email, to the person in charge.
Thus aiming for problem resolution very fast.

In the code below I will demonstrate how you can create a basic error notification mechanism.

Using the code

Let’s review the tasks we need to achieve:

1. Collect windows event logs using Windows Azure Diagnostics
   (Microsoft.WindowsAzure.Diagnostics.Management namespace)
2. Retrieve log errors from the WADWindowsEventLogsTable
3. Send email notification

Collect windows event logs using Windows Azure Diagnostics

Remote configuring windows event logs

using Microsoft.WindowsAzure;
using Microsoft.WindowsAzure.Diagnostics.Management;


// fetch from the windows azure portal
const string storageAccoutName = "INSERT-AZURE-STORAGE-NAME";
const string privateKey = "INSERT-STORAGE-PRIVATE-KEY";
const string deploymentId = "INSERT-DEPLOYMENT-ID";
const string roleName = "INSERT-ROLE-NAME";
const string roleInstanceName = "INSERT-ROLE-INSTANCE";
var storageAccount = CloudStorageAccount.Parse(
                                            String.Format("DefaultEndpointsProtocol=https;AccountName={0};AccountKey={1}",  
                                                                                               storageAccoutName, privateKey));

// Get the diagnostics manager for the entire storage account.
var diagnosticManager = storageAccount.CreateDeploymentDiagnosticManager(deploymentId);

// Get diagnostics manager for the specific role instance.
RoleInstanceDiagnosticManager roleDiagManager = diagnosticManager.GetRoleInstanceDiagnosticManager(roleName, roleInstanceName);

//Modify current configuration
var currentConfiguariton = roleDiagManager.GetCurrentConfiguration();

// Collect only application event error logs
currentConfiguariton.WindowsEventLog.DataSources.Add("Application!*");
currentConfiguariton.WindowsEventLog.ScheduledTransferPeriod = TimeSpan.FromMinutes(1);
currentConfiguariton.WindowsEventLog.ScheduledTransferLogLevelFilter = Microsoft.WindowsAzure.Diagnostics.LogLevel.Error;

//Commit the changes
roleDiagManager.SetCurrentConfiguration(currentConfiguariton);

public List<EventLogData> QueryEventLogData(LogLevel logLevel, string deploymentid, string roleName, 
                                                        string roleInstanceName, DateTime startPeriod, DateTime endPeriod)
{
    EventLogDataContext context = new EventLogDataContext(accountStorage.TableEndpoint.ToString(), accountStorage.Credentials);
    var data = context.PerfData;

    CloudTableQuery<EventLogData> query = null;

    query = (from d in data
             where d.PartitionKey.CompareTo("0" + startPeriod.Ticks) >= 0
                                    && d.PartitionKey.CompareTo("0" + endPeriod.Ticks) <= 0
                                     && d.Level == (int)logLevel
                                         && d.EventTickCount >= startPeriod.Ticks
                                             && d.EventTickCount <= endPeriod.Ticks
                                                  && d.DeploymentId == deploymentid
                                                     && d.Role == roleName
                                                         && d.RoleInstance == roleInstanceName
             select d).AsTableServiceQuery<EventLogData>();

    List<EventLogData> selectedData = new List<EventLogData>();
    try
    {
        selectedData = query.Execute().ToList<EventLogData>();
    }
    catch
    {
    }
    return selectedData;
} 

public static void sendEmail(string messageSubject, string messageBody, EmailClientConfiguration emailConfig)
{
    try
    {
        MailMessage msg = new MailMessage()
        {
            Subject = messageSubject,
            From = new MailAddress(emailConfig.From)
        };

        msg.To.Add(new MailAddress(emailConfig.To));

        msg.Body = messageBody;



        using (SmtpClient smpt = new SmtpClient()
        {
            Host = emailConfig.SMTPHost,
            Port = 25,
            EnableSsl = true,
            Credentials = new NetworkCredential(emailConfig.UserName, emailConfig.Password)
        })
        {
            smpt.Send(msg);
        }
    }
    catch (Exception ex)
    {
        MessageBox.Show(ex.ToString());
    }

}

Points of Interest

In Quest Software we developed a very handy performance monitoring tool named Spotlight on Azure that enables you to easily control azure resources and isolate performance problems in your applications from the role instance up to the azure subscription account.
Follow us on QuestCloudTools.com

This article, along with any associated source code and files, is licensed under The Code Project Open License (CPOL)