Category: azure cdn
djclark45 on Mon, 08 Apr 2019 08:15:34
I noticed sometime in the past month that our Standard Akamai CDN has become extremely slow. It mostly is serving small static files (mostly JS / CSS / smaller images)
When running tests on https://pulse.turbobytes.com for response times to fetch files across the globe (always looking at 2nd run not first so as to not take into effect first load cache miss), Origin's TTFB are MUCH faster than our Standard Akamai's TTFB across the board. This was not always the case.
I set up a second CDN profile tonight on Standard Microsoft CDN just to test, and this CDN profile is very fast (faster than both Origin and Standard Akamai)
Has there been a prolonged outage / issue with Standard Akamai CDN profiles or does anyone know how we can go about troubleshooting this?
Average results fetching the same file (many agents across world fetching same file 2nd fetch attempt):
Type | DNS | Connect | TLS | TTFB
Origin | 90 ms | 163 ms | 389 ms | 179 ms
Akamai | 62 ms | 11 ms | 131 ms | 368 ms
Microsoft | 47 ms | 12 ms | 122 ms | 33 ms
Important thing to note is differences in TTFB.
I'm unsure if this is something we could have caused by changing configuration. Compression is on in both instances, caching is set to override / 365 days / cache every unique URL in Akamai. Tested Akamai with no caching / compression and problems still persisted.
Help much appreciated.
msrini - MSFT on Mon, 08 Apr 2019 09:12:32
Thank you for reaching out. I did a similar test with Akamai CDN and I do noticed that the TTFB is higher than Origin.
But that is for the very first time you run the test. When I ran the test again, I saw significant improvement in TTFB.
Can you click on Run test again and check ?
djclark45 on Mon, 08 Apr 2019 23:15:59
Hi Msrini - thank you for taking a look.
That did not fix it.
I tried again just now (running 2 more tests for the same file) and both times are still slower than origin.
For more detail:
The 1st time I ran the test it was extremely slow (before the CDN has it cached), the 2nd test (and 3rd, 4th, 5th tests) are all faster than the 1st but are all still much slower than origin. This obviously defeats the purpose of using a CDN. This is a relatively new development and our CDN implementation was not always slower than fetching directly from origin.
Additionally, the problem is only appearing to happen with Azures' Standard Akamai CDN. Azure's Standard Microsoft CDN works fine during our tests (as in faster than origin)
Some more testing:
Created a 2nd Azure Akamai CDN with default settings / no customization, still seeing very slow results (slower than origin).
As I mentioned in my first post, Azure Microsoft CDN with default settings / no customization works correctly. This is specific to Akamai CDN
msrini - MSFT on Tue, 09 Apr 2019 05:00:09
The test which I ran had a significant improvements when I ran the test again. As it is more specific to your environment, I would suggest to raise a support ticket and check the logs to understand better.
If you do not have support plan, let me know, I can raise one time free support for you.
djclark45 on Tue, 09 Apr 2019 06:02:08
I do not have a support plan and would greatly appreciate if you could raise the support issue for me.
msrini - MSFT on Tue, 09 Apr 2019 06:18:10
To open a support request for this issue, please drop an email to AzCommunity@microsoft.com along with your subscription ID and the link to this thread.