The case of the not so ConcurrentDictionary

I was looking at our DevOps dashboards and saw some really weird patterns: So I pinged my colleague who owns this service and he noticed it was actual very predictable: Like clockwork, once a minute – he went further and got a PerfView which showed high contention on a newly added ConcurrentDictionary: He then asked…

0

The mysterious case of the 1 minute pauses

I spend a lot of time debugging issues on our service – we have a big team and periodically we hit some really weird issues that get escalated to me. In this particular case, we deployed our new sprint, full of exciting features to our dogfood server, and after a day or two, people started…

4

Troubleshooting ReaderWriterLockSlim issues

One wouldn’t think there would be anything to troubleshoot but we somehow keep having problems so I thought I’d share how we debug these issues: Imagine a situation where you notice your application not making progress – you take a dump and see something like this: 0:1199> !ClrStack OS Thread Id: 0x294c (1199) Call Site [HelperMethodFrame_1OBJ:…

0

How to diagnose SqlConnection Leaks

This is a fairly common problem – you test your app, everything works great. Throw it into production and then it stops working and you see a lot of these: System.InvalidOperationException: Timeout expired.  The timeout period elapsed prior to obtaining a connection from the pool. You then check the number of connections in Perfmon and…

2