John.Borovski

Ok. That’s embarrassing to speak about own stupid mistakes, but I have to update my previous answer, so that nobody would me misled.

Main source of WSODs and timeouts is misconfiguration of php-fpm limits:
pm.max_children – maximum php-fpm child processes, spawned for pool
pm.start_servers – amount of child processes at start up
pm.min_spare_servers – min idling childs
pm.max_spare_servers – max idling childs
pm.max_requests – requests, handled by child before restart

You should come up with amount of RAM that can be spared for php-fpm in general, then determine how much is consumed by single child (top will help here; empty process started with 25MB). Childs RAM usage grows while processing requests, so do not stick to minimum value. I suppose pm.max_requests value affects max size process can grow in RAM.
RAM utilization mentioned on forums, is about 45 MB per process; so if we want to give our php sites ~=1,8 GB RAM, it would be 40 processes.
An updated config for these conditions below:

[global]

pid = run/php-fpm.pid

[SITE]
listen = /var/run/php-fpm.sock
listen.owner = www
listen.group = www
listen.mode = 0666

listen.backlog = -1
listen.allowed_clients = 127.0.0.1

user = www
group = www

pm = dynamic
pm.max_children = 30
pm.start_servers = 20
pm.min_spare_servers = 10
pm.max_spare_servers = 30
pm.max_requests = 400

slowlog = /var/log/php-slow.log
request_slowlog_timeout = 5s

env[HOSTNAME] = $HOSTNAME
env[PATH] = /usr/local/bin:/usr/bin:/bin
env[TMP] = /tmp
env[TMPDIR] = /tmp
env[TEMP] = /tmp

[OTHER SITE]
listen = /var/run/php-fpm1.sock
listen.owner = www
listen.group = www
listen.mode = 0666

listen.backlog = -1
listen.allowed_clients = 127.0.0.1

user = www
group = www

pm = dynamic
pm.max_children = 10
pm.start_servers = 10
pm.min_spare_servers = 5
pm.max_spare_servers = 10
pm.max_requests = 400

slowlog = /var/log/php-slow.log
request_slowlog_timeout = 5s

env[HOSTNAME] = $HOSTNAME
env[PATH] = /usr/local/bin:/usr/bin:/bin
env[TMP] = /tmp
env[TMPDIR] = /tmp
env[TEMP] = /tmp

Hopefully, that’s it.

@realmag777
Thanks for answer!

I rechecked on my test installation (both default settings and ‘Currency storage: transient’, and woocommerce + currency switcher (latest versions) work fine, nothing related to switcher in php-slow.log

It seems, it’s an installation-specific problem, depending on other plugins installed.

For now I can’t trace the problem, but it’s doesn’t look like currency switcher’s fault anymore.

Once again thanks.

Actually by now I’m somewhat confused. I’ll try to describe taken steps precisely.

WP version: 4.4.2
WPGlobus version: 1.4.9
Easy google fonts version: 1.3.9

Last test steps and setting:
1) WPGlobus enabled
2) theme customization -> typography -> Default Typography -> Paragraphs:
active font family: Impact
3) changing active font family to Arial
changes are shown in preview
4) saving and exiting customization
5) refreshing page and reopening customization menu:
– font did not change on page;
– settings in default typography paragraphs active font are reverted to Impact.
6) Disabling WPGlobus
retaking steps 2)-5)
results of step 5):
– font changed to arial;
– changes in customization menu saved.
7) enabling WPGlobus and rechecking: changes still there

This made me think that problem might be somehow connected with multilingual in theme customization menu.

Sorry, I was mistaking. Problem still there:
link to images
I have to reopen this thread.

Tested on twenty fifteen, pluto and customized dustland express.

Can try other themes if needed.