Add Open Connection count to Function App
We are using a Function App for consuming events from an EventHub, to process each event we make 4-5 REST calls and we find that our S3 instances run out of outbound connections resulting in ETIMEDOUT errors. We opened a support case and we are troubleshooting. However to make it easier to debug and to allow us to put alerts in place it would be nice to have the number of open connections available through the Portal and be able to attach alerts..
We tried to run netstat from Kudu but thisis not permitted (Access Denied)
Update: Still planned!
This is something that we have enabled internally, and are in the planning process of highlighting TCP connections for customers in the “Diagnose and Solve problems” tab. However, we do not have an ETA yet.
Thanks for the feedback!
Azure Functions Team
The TCP connections pane has disappeared in the new version of the "Diagnose & Solve Problems" page. And not only in that, the pane wasn't very useful in the first version of the page. It showed the number of connections (good) but gave absolutely no details to help you diagnose what was creating the connections e.g. the counts of connections to different ip addresses? or the counts of connections to other azure services (usually the case).
Exceeding the host thresholds is one of the most frustrating and frequent problems (ran into it on three consecutive projects with enterprise clients) we run into when doing anything remotely high volume with Azure Functions. There needs to be better diagnostics around this.
When will this be available?
Michael Daw commented
Please do this soon. Even writing Function Apps in such a way that they should not leak connections, apps eventually fail for this reason, yet there is no way to diagnose or troubleshoot the issue.
Tom Robinson commented
"Moved over to the Azure Functions forums."
Could you provide a link?
Stephen Wing commented
Yes, this is something that's badly needed, we're running into issues with this also in Functions. Maarten, you may wish to look at the following link to possibly resolve your underlying issue:
Unfortunately, this does not solve our issue, because it's primarily calls to other Azure services that are using up all of our connections...
Moved over to the Azure Functions forums.