Are you struggling with the speed and performance of your Azure Web App? Don’t let slowdowns keep you from getting the most out of your Azure web application. There are many ways to solve this issue and speed up your site.  This blog will help you how to troubleshoot the performance issues and identify the root causes that are making your Azure Web Application slower. The techniques discussed in this blog will help you to drastically improve your azure web app performance. Learn these tips and apply them in your project to optimize your Web app performance quickly and easily for maximum results.

What is Azure Web Application?

An Azure Web Application is a type of cloud computing service offered by Microsoft’s Azure platform that allows you to host and manage your web applications in the cloud. In simple words, it’s a way for developers to build and deploy web applications on Microsoft’s cloud infrastructure without having to worry about the underlying infrastructure, such as servers, networking, and storage.

Azure Web Applications are important because they provide a scalable and flexible platform for hosting web applications. With Azure, developers can quickly and easily deploy their applications to the cloud, and then scale the infrastructure up or down as needed to handle changes in traffic or demand.

Let’s understand why your Azure Web Application is running slowly.

Causes of Slow Performance in Azure Web Applications

If your Azure Web Application is running slowly, it can lead to a poor user experience and negatively impact the performance of your application. Below are some of the reasons which describe why it’s happening:

1. Inefficient code

If your Azure Web Application code is not optimized for performance, it can lead to slow performance. Because of using inefficient algorithms, improper use of loops, and not following best practices for coding, there will be a performance issue.

Here’s an example of inefficient code:

public List<string> GetCustomers() {

List<string> customerList = new List<string>();

using (SqlConnection connection = new SqlConnection(connectionString)) {

connection.Open();

using (SqlCommand command = new SqlCommand("SELECT * FROM Customers", connection)) {

SqlDataReader reader = command.ExecuteReader();

while (reader.Read()) {

customerList.Add(reader["Name"].ToString()); }

reader.Close(); }

connection.Close(); }

return customerList;

}

In the above code, you will retrieve a list of customers from a database using ADO.NET. However, it is inefficient because it retrieves all the columns from the Customers table, even though it only needs the Name column. This can cause slow performance, mainly if the table contains a large number of columns.

A more efficient way to retrieve only the required data is to modify the SQL query to select only the required column:

public List<string> GetCustomers() {

List<string> customerList = new List<string>();

using (SqlConnection connection = new SqlConnection(connectionString)) {

connection.Open();

using (SqlCommand command = new SqlCommand("SELECT Name FROM Customers", connection)) {

SqlDataReader reader = command.ExecuteReader();

while (reader.Read()) {

customerList.Add(reader["Name"].ToString()); }

reader.Close(); }

connection.Close(); }

return customerList;

}

In the above code, the SQL query retrieves only the Name column from the Customers table, resulting in faster and more efficient performance. By modifying the SQL query to retrieve only the required data, the application can significantly reduce the amount of data transferred from the database to the application, leading to better performance.

2. Excessive resource consumption

If your Web Application consumes resources such as CPU, memory, or disk, it can lead to slow performance. This can be caused by large file uploads or downloads, or an unusually high number of requests. You can optimize your code to reduce resource consumption, use caching to minimize the number of requests to the server, or upgrade your Azure Web Application plan to a higher tier with more resources.

Here’s an example of code that uses excess resources:

public void UploadFile(string fileName, byte[] fileContent) {

using (FileStream stream = new FileStream(fileName, FileMode.CreateNew)) {

stream.Write(fileContent, 0, fileContent.Length);

}

}

In the above code, it uploads a file to the web server by writing its contents to disk using a FileStream. This approach can cause excessive resource consumption, especially if the file is large or if there are a large number of file uploads happening simultaneously.

A more efficient way to handle file uploads in Azure Web Applications is to use Azure Blob Storage. Here’s an example of how to upload a file to Azure Blob Storage:

public void UploadFileToBlobStorage(string fileName, byte[] fileContent) {

CloudStorageAccount storageAccount = CloudStorageAccount.Parse(connectionString);

CloudBlobClient blobClient = storageAccount.CreateCloudBlobClient();

CloudBlobContainer container = blobClient.GetContainerReference(containerName);

if (!container.Exists())

{

container.Create();

}

CloudBlockBlob blob = container.GetBlockBlobReference(fileName);

blob.UploadFromByteArray(fileContent, 0, fileContent.Length);

}

In the above code, we have used Azure Blob Storage to store the uploaded file instead of writing it to disk. This approach is more efficient because Blob Storage is designed for handling large files and can scale to handle high volumes of uploads simultaneously. Additionally, it allows for easier management of uploaded files, including versioning, backup, and disaster recovery.

3. Improper use of caching

Caching can significantly improve the performance of Azure Web Applications. But, if it’s not used properly, it can cause slow performance. Improper use of caching is due to not caching the right objects, caching too much data, or not expiring cache objects. You should use a distributed caching solution such as Azure Cache for Redis or implement local caching using in-memory cache objects.

Here’s an example of improper use of caching:

public List<string> GetCustomers() { List<string> customerList;

if (HttpContext.Current.Cache["Customers"] != null) {

customerList = (List<string>)HttpContext.Current.Cache["Customers"]; }

else { using (SqlConnection connection = new SqlConnection(connectionString)) {

connection.Open(); using (SqlCommand command = new SqlCommand("SELECT * FROM Customers", connection)) {

SqlDataReader reader = command.ExecuteReader();

customerList = new List<string>(); while (reader.Read()) {

customerList.Add(reader["Name"].ToString());

}

reader.Close();

}

connection.Close(); HttpContext.Current.Cache.Insert("Customers", customerList, null, DateTime.Now.AddMinutes(30), TimeSpan.Zero);

}

}

return customerList;

}

The above code retrieves a list of customers from a database using ADO.NET and uses ASP.NET caching to store the results for 30 minutes. If the data in the database is frequently changing, it will cause slow performance.  In such cases, the cache may be serving stale data, leading to incorrect results for the user.

A better approach is to use cache invalidation to ensure that the cache is refreshed with the latest data when it changes. Here’s an example of how to use cache invalidation:

public List<string> GetCustomers() { List<string> customerList;

if (HttpContext.Current.Cache["Customers"] != null) {

customerList = (List<string>)HttpContext.Current.Cache["Customers"]; }

else {

using (SqlConnection connection = new SqlConnection(connectionString))

{

connection.Open(); using (SqlCommand command = new SqlCommand("SELECT * FROM Customers", connection))

{

SqlDataReader reader = command.ExecuteReader();

 customerList = new List<string>();

while (reader.Read()) {

customerList.Add(reader["Name"].ToString());

}

reader.Close();

}

connection.Close(); SqlCacheDependency dependency = new SqlCacheDependency("DatabaseName", "Customers");

HttpContext.Current.Cache.Insert("Customers", customerList, dependency, DateTime.Now.AddMinutes(30), TimeSpan.Zero);

}

}

return customerList;

}

In this updated code, we have used SqlCacheDependency to set up a cache dependency on the database table that contains the customers. This ensures that the cache is invalidated and refreshed with the latest data when the table is updated. This approach provides better performance and ensures that users receive the latest data from the database.

4. Database issues

Slow queries, a high number of database requests, or an overloaded database will cause poor database performance which will lead to slow performance. You should use Azure’s monitoring and diagnostic tools to identify the areas of your application that are causing the most database activity and optimize your queries or upgrade your database plan.

Here’s an example of a database issue:

public void AddOrder(Order order) {

using (SqlConnection connection = new SqlConnection(connectionString))

{

connection.Open(); using (SqlCommand command = new SqlCommand("INSERT INTO Orders (OrderId, CustomerId, OrderDate) VALUES (@OrderId, @CustomerId, @OrderDate)", connection))

{

command.Parameters.AddWithValue("@OrderId", order.OrderId);

command.Parameters.AddWithValue("@CustomerId", order.CustomerId);

command.Parameters.AddWithValue("@OrderDate", order.OrderDate);

command.ExecuteNonQuery();

}

connection.Close();

}

}

In the above code, it will add an order to a SQL Server database. If the database is not properly optimized, it will cause slow performance. For example, if the table has a large number of records or if the indexes are not properly configured, this can cause slow performance when inserting new records.

A better approach is to optimize the database for the expected workload. This will involve tuning the database indexes, partitioning the table, or using sharding to distribute the data across multiple database instances

Here’s an example of how to use Azure Cosmos DB to store order data:

public async Task AddOrder(Order order) {

DocumentClient client = new DocumentClient(new Uri(endpointUrl), authorizationKey);

await client.CreateDocumentAsync(UriFactory.CreateDocumentCollectionUri(databaseName, collectionName), order);

}

In the above code, we have used the Azure Cosmos DB SDK to store the order data as a JSON document. This approach provides better scalability and performance than using a traditional relational database, especially for applications that require high write throughput or low latency access to data.

5. Network latency

A slow network connection or high network traffic can cause network latency which will cause slow performance. To solve this, you should use a Content Delivery Network (CDN) to improve the delivery of static content, optimize images and other media, or use Azure’s performance monitoring tools to identify network latency issues.

Here’s an example of how network latency can cause slow performance:

public async Task<string> CallWebService(string url)

{

 using (var client = new HttpClient())

{

var response = await client.GetAsync(url);

return await response.Content.ReadAsStringAsync();

}

}

In the above code, it will call an external web service using the HttpClient class. If the network latency is high or the external service is slow to respond, this can cause slow performance in the Azure Web Application.

A better approach is caching or asynchronous processing to avoid waiting for the external service to respond. Here’s an example of how to use caching to improve performance:

public async Task<string> CallWebService(string url) {

string cacheKey = "WebService_" + url;

string cachedResponse = (string)HttpContext.Current.Cache[cacheKey];

if (!string.IsNullOrEmpty(cachedResponse))

{

return cachedResponse;

}

using (var client = new HttpClient())

{

var response = await client.GetAsync(url);

string responseString = await response.Content.ReadAsStringAsync();

HttpContext.Current.Cache.Insert(cacheKey, responseString, null, DateTime.Now.AddMinutes(5), TimeSpan.Zero);

return responseString;

}

}

In the above code, we have used ASP.NET caching to store the response from the external web service for a short period of time. If the response has been previously cached, we return it immediately, avoiding the need to call the external service again. This approach can significantly improve performance, especially for applications that call external services frequently.

6. External factors

Slow performance in Azure Web Applications can also be caused by external factors such as hardware or software failures, cyber-attacks, or spikes in traffic. To address this, you can use Azure’s built-in disaster recovery and high availability features to ensure that your application remains available and responsive during any unforeseen events.

How to troubleshoot Performance Issues?

Here is a step-by-step guide on how to troubleshoot performance issues in Azure Web Applications:

STEP 1: Identify the symptoms

Identify the symptoms of the performance issue, such as slow response time, high CPU usage, or frequent timeouts. Use monitoring and diagnostic tools such as Azure Application Insights to collect performance metrics and identify patterns in your application’s behavior.

STEP 2: Determine the scope

Determine the scope of the performance issue, such as whether it affects all users or only a subset of users, and whether it is isolated to a specific area of your application. Use the information collected in step 1 to determine the scope of the issue.

STEP 3: Collect data

Collect data on the performance issue, such as log files, performance metrics, and traces. This may involve enabling diagnostic logging, configuring monitoring tools such as Azure Application Insights, and using profiling tools to analyze your code.

STEP 4: Analyze the code

Use profiling tools such as Azure Profiler to identify performance bottlenecks in your code. This may involve analyzing the call stack, identifying long-running queries or expensive operations, and looking for opportunities to optimize your code.

STEP 5: Optimize the code

Take steps to optimize your code, such as improving the efficiency of queries, reducing the amount of data retrieved from the database, or optimizing loops and data structures. Use the information collected in step 4 to guide your optimization efforts.

STEP 6: Verify the fix

Verify that the performance issue has been resolved by monitoring the application and verifying that the symptoms are no longer present. Use monitoring and diagnostic tools such as Azure Application Insights to track performance metrics and ensure that the issue has been fully resolved.

STEP 7: Update the architecture

If necessary, update your application architecture to prevent similar performance issues from occurring in the future. This may involve adding additional resources, modifying your deployment strategy, or changing your application design to improve scalability and performance.

STEP 8: Document the solution

Document the solution to the performance issue, including the symptoms, root cause, and steps taken to resolve the issue. This will help you to identify similar issues in the future and quickly implement effective solutions.

By following these steps, you can troubleshoot performance issues in your Azure Web Application using code and diagrams, and maintain a high level of performance and availability for your users.

Conclusion

An Azure Web Application is a powerful tool that allows you to build and deploy web applications in a scalable, reliable, and secure way. However, if your Azure Web Application is running slowly, it can impact the performance and availability of your application, leading to a poor user experience and potentially affecting your business.