We have an install of the latest Craft on a Nexcess shared account. By default, the account runs PHP 5.4.x. We were working on and configuring the site for about a week - no issues of any kind until today. We used the Nexcess control panel to update the PHP version to 5.6.3 (for a plugin we were going to use). After doing so, we found that saving entries or certain configuration elements in settings would take 5+ minutes to complete. We downgraded back to 5.4.x and still the behaviour persists. Unfortunately, it does not seem to be 100% consistent. I would say it happens about 90% of the time and cannot find any common thread as to when it happens and when it does not.
Saving one entry is generating about 1.4 MB of Craft log files:
Beyond the Craft logs, I don't see a php error in the PHP logs but there are these Apache errors when saving the entry:
[Fri May 05 07:28:46 2017] [error] [client xx.xx.xx.xx] FastCGI: incomplete headers (0 bytes) received from server "/dev/shm/cadexdev-php.fcgi", referer: http://www.cadex-dev.ca/shop/admin/entries/multiUse/new
I don't know if this is host-related. I do have a ticket open with Nexcess but am not certain if this is something specific to Craft instead?
EDIT: Also, a curious behaviour around this issue. If I save an entry and only wait, say, 20 seconds, quit my browser and then re-open and go to the entries page, the entry is there with the saved changes. No 5+ minute wait.