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XF 1.4 Performance Issues - Slow (>30s) click response

#1
Hi,

(please forgive my ignorance, I am new to this whole hosting thing. Just an old UNIX hack from before the internet days)

I had previously posted about SQL query perforamnce but that was an assumption on my part. Here are the raw observations. Any advice would be greatly appreciated.

We are trying to debug intermittent very sluggish response times for our users.

Debug started with Chrome>Developer Tools>Network trace attached. This shows that the delay is happening upon the initial click waiting for the page to be "built" by the host. See slow_response.png

slow_response.png

I then SSH'd into the host and ran top and kept clicking until another slow event occured. I have been able to correlate the sluggish response to a large number concurrent of "php-cgi" processes on the host. They are all tyring to run at the same time and only getting a fraction of the CPU utilization. See summary of process log trace attached process_debug.jpg It gets much worse (more php-cgi processes) but that log file is at home and I'm at work.

process_debug.JPG

By monitoring the "top" output over SSH with a very fast refresh rate (0.3sec), I can see that the php-cgi processes are direct results if click events on the web site. Thus, I suspect we are just seeing a large number of users simultaneously clicking.

Questions:
Is this likely the result of simply too many simultaneous clicks?
Is it possible these are add-ons running causing this?
Cron jobs running too often or possibly all at once?

Mucho thanks for any advice/questions/help anyone can give!

Best regards,
Frank and Sean
 

Brogan

XenForo moderator
Staff member
#2
It does appear to be quite slow.
The initial get request for me is anywhere from 1.5 seconds up.

Who is your host?
Is it a shared or dedicated server?
 
#3
Dirt low budget server for $4/mo. 1 CPU.... Bighting the bullet and moving to a better hosting company. Hope this don't come up again.

But still, I would like to know what causes these bursts of processes to show up on the host.
 

Brogan

XenForo moderator
Staff member
#4
I suspect the server is massively oversold so performance will depend on how many sites are being hosted and the activity on them.
 
#5
I suspect the server is massively oversold so performance will depend on how many sites are being hosted and the activity on them.
Well we are only getting/paying for one CPU, they have us throttled. Server load average is never more than 12 and there are 24 CPUs. You can see that all of our proc's CPU utilization adds up to 100.

Edit: actually it does not add up! We are being cheated!!! Dumping them and moving on