Issue Slow client download speeds for large files

[SolarStorm]

Server operating system version

Alma Linux 8 - Linux 4.18.0-513.5.1.el8_9.x86_64

Plesk version and microupdate number

Version 18.0.61 Update #3

Hello everyone,

I'm new to Plesk, coming from a Cpanel server. I'm in the middle of migrating to Plesk and have discovered an issue which I'd like to share, just in case someone can assist.

Both Cpanel and Plesk servers are with the same hosting provider and have an identical performance metric.

e.g DD shows the same nvme speed, WGET also shows similar download speeds.

The problem is when a client is trying to fetch a large from from the Plesk server, where performance is severely degraded, to the point it stalls many times and sometimes fails to download.

To keep the environments as identical as possible, I've placed the same 500MB test download file on both production (Cpanel) and new Plesk servers. In the attached image, you'll notice the file being downloaded at almost 4MB/sec while the Plesk site download speed is between 100KB/sec - 400KB/sec. This particular download from the Plesk server failed.

I've been working with my hosting support on this for a few days now but I can't figureout where the issue is. My home connection is a 40Mb/sec download. I performed these tests from work (1 Gig fibre) and the results are similar.

I noticed that Plesk is using Ngix and found some similar documentation where users were expericing the same slow download speeds, tried the suggestions (disable Ngix proxy etc) but it made no difference.

Closing, I should note that the CMS I loaded on the Plesk server worked nice and fast - the problem seems to be focused purely on downloads. I also had very low download speeds even when using FTP or the Plesk GUI File Manager.

If anyone has any suggestions, I'd really appreciate it.

Many thanks,

Chris.

 

[Kaspar@Plesk]

Strange, there is no throttling or imposed download limit in Plesk. Don't hesitate to reach out to our support team for an investigation.

 

[SolarStorm]

Strange, there is no throttling or imposed download limit in Plesk. Don't hesitate to reach out to our support team for an investigation.

Kaspar,

Thanks for your reply. I know this is a really odd issue. My hosting provider has already opened a support ticket with Plesk, but they are taking 12+ hours to reply back.

In their initial reply, they tested download speeds from the server using WGET and achieved 20+MB/Sec, however when they tried via HTTPS, the download slowed down to 11KB/sec! They are now checking with the developers.

I'm contemplating if I should open a new ticket directly with them or not!

Am I able to supply the download URL and see what speeds others reading this thread are achieving?

 

[Kaspar@Plesk]

You're welcome to share a download link for other users to try.

 

[SolarStorm]

Excellent. I'd really appreciate it if people can test this and provide screenshots of their download speeds. It would be super useful to also know their location and link speed.

Keep it mind that the download starts somewhat fast, but quickly slows down.

Link: https://www.nightsky.gr/500MB

Thank you very much!

 

[Kaspar@Plesk]

12 MB/s via browser on my desktop computer and 21.4 MB/s from test VM via wget.

 

[SolarStorm]

Thanks Kaspar for the feedback and info - Can you please try it with a normal web browser as that where the problem seems to easily replicate. Plesk support got similar speeds with WGET, but only a few KB/sec when using a normal GUI browser.

Thank you.

 

[Kaspar@Plesk]

Thanks Kaspar for the feedback and info - Can you please try it with a normal web browser as that where the problem seems to easily replicate. Plesk support got similar speeds with WGET, but only a few KB/sec when using a normal GUI browser.

Thank you.

The 12 MB/s where via browser on my desktop computer.

 

[AYamshanov]