Trying to narrow down the cause, but figure this forum is the best place to start.
Running Multi-Site and using the stock Commons in a Box theme for the front page. P2 Theme for the subsites created below the parent site.
I logged into the back end today to make sure all was well. Found WP 3.5.2 upgrade offered, along with some updates to plugins and the P2 theme.
I did the upgrade for WP first and was told I need to do the 'Network Update' to update all the sites, so I accepted this option. All was evidently OK until an error popped up. The error is pasted in below, with some domain modifications to protect the innocent…
Warning! Problem updating http://blog.abcconsultants.ca/sitew. Your server may not be able to connect to sites running on it. Error message: couldn’t connect to host
Which is weird, because the sites are all physically on the same drive on the same multi-site install. Why this one is a problem I don’t know! I think it was the last site I created, but don’t think that should matter. The dashboard for this problem site shows 3.5.2 as the version in use.
No other obvious problems, so I did the theme and plugin updates before poking into the single subsite problem.
I then noted that the admin area was dog slow. But the public side of the site remains as snappy as it ever was.
No load is noted on the server during the delays (watching 'top' from the command line). It looks outwardly very much like a DNS timeout problem, where the server has no additional load but simply does nothing until the DNS officially fails… if you know what I mean. No errors that I can find, but I honestly don’t know where besides the typical Apache logs I should be looking. The delay is very close to a minute and the browser simply shows ‘waiting for server’ during the delay. Once the connection with the server is finally established, the page populates as quick as ever. If there was a database issue, I would assume the public side would see the same delays??
I found a posting elsewhere discussing a similar symptom and note that the problem was tracked back to a routine that was attempting to notify the admin user of a new theme version. I don’t know if that’s possibly a clue here or not.
Any suggestions as to where I should be looking?