HttpClient Socket Exhaustion

M Nouman Berlas — Sat, 27 Jun 2026 13:00:21 +0000

🔥 Your .NET API is Slowly Dying (And You Don't Even Know It)

Last month, our production system started timing out randomly. No errors. No warnings. Just... slow death.
After 3 sleepless nights and diving through 60+ microservices, I found the culprit:

var client = new HttpClient(); // This single line
Here's what was happening:
Every HTTP call was creating a NEW TCP socket. Under load, we exhausted the system's connection pool. Requests started queuing. Response times went from 200ms to 30+ seconds.

The Silent Killer:
• ✅ Your code compiles fine
• ✅ Your tests pass
• ✅ It works in dev/staging
• ❌ It crashes in production under real load

The Fix That Saved Our SLA:

// In Startup.cs
services.AddHttpClient("MyService", client => { client.Timeout = TimeSpan.FromSeconds(120); })
.ConfigurePrimaryHttpMessageHandler(() => new SocketsHttpHandler { PooledConnectionLifetime = TimeSpan.FromMinutes(2), PooledConnectionIdleTimeout = TimeSpan.FromMinutes(5), MaxConnectionsPerServer = 20, AutomaticDecompression = DecompressionMethods.GZip | DecompressionMethods.Deflate });

// In your service public class MyService { private readonly IHttpClientFactory _clientFactory; public MyService(IHttpClientFactory clientFactory) { _clientFactory = clientFactory; } public async Task<string> GetDataAsync() { var client = _clientFactory.CreateClient("MyService"); // Use the client } }

The Results:
📊 95% reduction in connection failures
⚡ 40% improvement in throughput
💰 Prevented potential revenue loss from timeouts

The Lesson:
IHttpClientFactory isn't just a "best practice" - it's a production survival tool.
Microsoft documented this in 2018, but I still see this anti-pattern EVERYWHERE.
Have you been bitten by socket exhaustion?

Share your battle story in comments 👇

#performance #dotnet #csharp #softwareengineering #productionissues #microservices #debugging #azure #performanceoptimization #lessonslearned #techleadership

Battle Stories Series

M Nouman Berlas — Sat, 27 Jun 2026 12:40:11 +0000

I will be writing about the real world instances that I have witnessed during my career from production issues. For almost all of the I have to spend the night figuring out the real cause and end up having to go through the team post mortem.
Love to hear about your production experiences as well. The first story to be followed soon :)

DEV Community: M Nouman Berlas

HttpClient Socket Exhaustion

Battle Stories Series