Issues with Fog 1.5.2

[K.Hays]

@george1421 I adjusted the file to match what you put in this post https://forums.fogproject.org/topic/11797/updated-from-fog-v1-50-to-v1-52-issue/25

Will test soon. Any other ideas?

[Quazz]

@k-hays Can you deploy an image to a single client without issue?

This seems to me like an issue with PHP-FPM getting overloaded.

On debian the pm.max_children directive is often stuck on 5 which is generally too low for most people. (40 is a good starting point for testing)

[K.Hays]

@quazz Yes. Single client works fine. I don’t know the specific number in which it starts to fail; but in a lab we image anywhere from 20 - 35ish computers and it seems to fail whenever we try those numbers. The issue also persisted when we started with ubuntu.

[Quazz]

@k-hays There’s currently some known issues with PHP-FPM settings/getting overloaded, particularily on debian based systems.

I definitely recommend checking the pm.max_children value (not 100% sure where it is on debian)

You should be able to check the PHP-FPM logs on the WebUI to see if it’s been complaining about not enough max_children or memory exhaustion or timeouts I think.

[K.Hays]

@quazz I’ll go digging. Any ideas?

[Quazz]

@k-hays Try grep -irl pm.max_children /etc

[K.Hays]

@quazz Ok I found it! Now, what do you think the max i should put there is. Sometimes we might image up to two, maybe three labs at a time. would 90 be a stretch?

[Quazz]

@k-hays It depends on how many resources your server has available to itself.

We haven’t done a ton of testing on the exact numbers. The value will depend on the amount of RAM and how much the average PHP-FPM uses.

Start with 40 as a safe value and go from there, imo.

[K.Hays]

@quazz Ok will do. I’ll end up testing this today as well. We’re using a server that has a lot of unused resources so we can devote a good bit to it. I also want to say that we are on the current dev-branch, so 1.5.4. These were all fresh builds as well, even on ubuntu. Does it automatically set the max children to 5 now?

[george1421]

@k-hays said in Issues with Fog 1.5.2:

. would 90 be a stretch?

Don’t do that much you could run into a situation of resource exhaustion. Under normal imaging you shouldn’t see more than 10 worker thread. For max children I would set it to 40.

If you are using FOG 1.5.2 or later here is what I would change in the www.conf file for php-fpm.

php_admin_value[memory_limit] = 256M
pm.max_requests = 2000
pm.max_children = 40
pm.min_spare_servers = 6
pm.start_servers = 5

Update those settings then restart php-fpm.

Queue up your multicast then on the fog server linux console start top then press P to sort by CPU usage. Watch, you should have 5-7 php-fpm worker threads running, they should be the top cpu users.

[K.Hays]

@george1421 Ok, does it make a difference if we do unicast? Just wondering

[george1421]

@k-hays The memory setting will help the unicast imaging too

But just to be sure none of your conditions have changed since your original post of 2 months ago? You are still having the same exact condition?

[K.Hays]

In terms of network yes. The server itself is the same, but it’s been reloaded to debian 9 and 1.5.4 as opposed to ubuntu and 1.5.2.

[K.Hays]

@k-hays Also if you meant the error, then yes. It is the exact same issue (or at least extremely similar). I made the changes and will test it again shortly.

[K.Hays]

So PHP wouldn’t restart and i’m pretty sure it was because i had set my min spare servers larger than the max. That being said, if my min is 6 (as you said) what should my max be?

Edit- @george1421 I set it to 6 just to see and PHP still failed with a different error this time. It says the start server can be less then the min spare and no more than the max. So what should i change them to?

[george1421]

@k-hays Max should be 40 as I posted below.

php_admin_value[memory_limit] = 256M
pm.max_requests = 2000
pm.max_children = 40
pm.min_spare_servers = 6
pm.start_servers = 5

[K.Hays]

@george1421 Yes, and it is currently set to 40. When i said max i meant the Max_spare_servers option. So what it’s telling me is that pm.start_servers cannot be a smaller number than pm.min_spare_servers. Or at least thats the error i’m getting. The last things you had me change (pm.Start_servers and pm,.mid_spare_servers) are apparently causing the error. Also the pm.max_spare_servers that needs to be set higher than what we set the start_servers options as well. could i just set them to 5,6,7 respectively? Im sorry, i’m really not entirely sure how this works

[K.Hays]

@george1421 Another update. I set Min_spare_servers = 6, max_spare_servers = 6, and start_servers = 6 and php successfully restarted/not sure if thats good or bad.

[george1421]

@k-hays said in Issues with Fog 1.5.2:

max_spare_servers = 6

Set that value to 40 and make sure you have the memory allocated to 256M and you should be good to go. Understand this fix will only address imaging and not your initial post of html in the FOS screen.

[K.Hays]

@george1421 ok so max_spare_servers needs to be 40. gotchya. Should i change the other 2 _servers settings from 6? Also should max_spare_servers be set to the same as number as pm.max_children?