1

We have a blue, green site and server farm set up for zero downtime deployment which works fine but we are seeing in the web logs for the site that does the routing that every now and then the wrong server is being sent requests.

2023-02-19 09:50:05 /DocumentView DID=23932&SERVER-ROUTED=LIVE-GREEN
2023-02-19 09:50:09 /FileDownload FID=50516&SERVER-ROUTED=LIVE-BLUE
2023-02-19 09:50:13 /Publish DocID=9154358&SERVER-ROUTED=LIVE-BLUE
2023-02-19 09:50:15 /SiteView DID=23932&SERVER-ROUTED=LIVE-GREEN

In this instance it tries to send two requests to Live-Blue which is set to Unhealthy and the site Stopped. The Health Test interval is set to 1 seconds (at the moment).

It's not happening a lot(maybe once every 25k request) but is very annoying to those that do get the 502 error message. (502.3 - Bad Gateway: Forwarder Connection Error (ARR).)

Anyone have any ideas on how to fix or diagnose the issue?

marc_s
  • 732,580
  • 175
  • 1,330
  • 1,459
JayTruman
  • 125
  • 1
  • 8
  • I've just found out that we are also getting a intermittent 404's on the redirecting site even though our global URL rewrite rule should have passed the request onto the server-farm. So a similar issue?! The ARR stops working correctly resulting in either a 502 couldn't route to the stopped site or a 404 couldn't find the path because the rewrite rule didn't kick in. – JayTruman Feb 20 '23 at 07:23
  • You can use [failed request tracking](https://learn.microsoft.com/en-us/iis/troubleshoot/using-failed-request-tracing/using-failed-request-tracing-rules-to-troubleshoot-application-request-routing-arr) to view detailed error information, If not enough information is available, you can also debug the cause using [IIS Debug Diagnostics Tool](https://www.microsoft.com/en-us/download/details.aspx?id=58210), this tool will generate detail log file, which will help you to identify the problem. – samwu Feb 21 '23 at 07:19
  • @samwu Thanks. I've had this running but it doesn't tell me why it chose to send the request to the wrong server it just shows that it did. It also doesn't show why it intermittently ignores the rewrite rule. – JayTruman Feb 23 '23 at 03:09
  • Have you analyzed your dump file? – samwu Feb 24 '23 at 10:00

0 Answers0