Daylight Atheism > Open Thread: Site Slowness, Continued

Open Thread: Site Slowness, Continued

I'm aware that this site has been having problems loading these past few days. I assure you all, I'm just as frustrated by it as you are. In a way, it's good news - these are a sort of growing pains; the slowness is at least in part because of the steady increases in traffic I've been getting. But these response times are intolerable, and I assure you all I'm working with my host to get it fixed as soon as possible.

If you're still having slowness, or if you're not, please comment about it here and let me know. The more information I have about the problem, the more it will help me work out a fix.

25 Comments

I've been having the slower issues for a few days now. It's much better than it was before, when I couldn't even get the site to load, but it's still sadly quite slow. I'm on a good cable broadband connection, with a computer under 2 months old, and no other sites I visit have such time delay problems, so it's not anything on my end.

Hope things get sorted out soon.

Comment by: Callandor | June 20, 2008, 9:23 pm

Same here. At least I've been able to get it to load now, it always timed out before. But I'm not really bothered by the load times.

Comment by: Petrucio | June 20, 2008, 11:08 pm

I can't recommend SliceHost enough. (They rent out Xen virtual machines.) They're the Daylight Atheism of hosting -- consistently excellent and logical, and the first place I send people who stand to benefit from their services. :-)

I frequently debate godbots, and it's a rare rebuttal of mine that doesn't link to EM and/or DA, so I have a keen interest in seeing your sites stay online. I don't know how you feel about "managed hosting", but I'd be honored to donate space on my Slicehost server for your sites, if you wish.

Comment by: Kevin DeGraaf | June 20, 2008, 11:20 pm

What I've been noticing is a delay before I start receiving data; after that happens, the page loads in short order.

Comment by: Alex Weaver | June 21, 2008, 12:39 am

What I've been noticing is a delay before I start receiving data; after that happens, the page loads in short order.

I've experienced the same effect.

I've also noticed some problems with the RSS feed, which should put less load on the server, but maybe it isn't a high priority. The feed often refuses to load or to show the most recent item on both Firefox and my phone, although the latter has a greater number of possible causes.

Comment by: James B | June 21, 2008, 4:29 am

It's about 9:30 AM Eastern U.S. time, and the load times are almost instantaneous on my end.

Looks like problem solved.

Comment by: Ingersoll's Revenge | June 21, 2008, 9:34 am

It's taking about me 40 seconds to one minute using Firefox to get from one page to another within the site today (21st June, 3.pm GMT). At work, I use Internet Explorer, and in the last week that hasn't even been able to get onto DA - after a couple of minutes it comes back with a "No response from server" error.

Not that I spend my precious working hours reading atheist websites or anything...

Comment by: yunshui | June 21, 2008, 10:01 am

I can't say I have any experience at all running a site nearly this big, but I have to imagine that most of the strain on your site is due to the WordPress method of showing a page:

1. Start PHP (or it's already loaded as a server module or running in a FastCGI server, if you're lucky)
2. Load the WordPress PHP script and generate its bytecode (or load cached bytecode courtesy of eAccelerator or similar, if you're lucky)
3. Pull the requested content out of MySQL and generate the corresponding HTML (or load the HTML from disk or memorycache with WP-Cache, if you're lucky)
4. Optionally, compress the content for transfer
5. Send it down the wire

Needless to say, this can all put quite a strain on the server. So what with the recurring performance issues we're having here, I have to ask: have you considered a static publishing platform, such as Movable Type?

I realize how much work it would be to switch from WP to another platform, having recently made the switch myself on a smaller site. But given how much less resource-intensive it is to serve static content with, e.g., Lighttpd than dynamic content with WordPress, even with every conceivable WordPress caching strategy implemented, maybe it's worth some consideration?

In contrast, here's what happens when someone requests a statically-generated Movable Type page from my Lighttpd server:

1. Load the pre-generated page from disk (or a cached, pre-generated and pre-compressed page from disk or memory if you're lucky)
2. Send it down the wire

Anyway, best of luck, I hope the site's back to 100% soon!

Comment by: Mark | June 21, 2008, 10:09 am

I am also have a slice at SliceHost. Let's hear it for AMD chips!!

Setting up email seems to be a pain. You need an SMTP server and a POP3 server, and in some cases a database as well.

Comment by: EKM | June 21, 2008, 11:00 am

Regarding static publishing platforms: The most recent tweak I made to the site was installing WP Super Cache, a plugin that turns frequently-viewed pages into static HTML that can be served directly without loading PHP. That seems to have made a lot of difference, although on the downside, it does interfere with my traffic stats. I'm looking into configuring Apache itself to solve that.

This whole experience has been an eye-opener for me regarding the CPU usage of WordPress. I had no idea it puts so much strain on the server. I like to think my site is fairly popular, but I know it's nothing compared to the big guns out there, and I didn't think the traffic was so high that a decently configured web server would have problems with it. I'm getting the impression that WP was designed for ease of use more than performance. After all the effort I've invested into getting everything set up the way I like it, I doubt I'll have the time or the inclination to migrate everything to a different software platform. But if I were to start all over, knowing what I know now, I might consider an alternative.

That said, WordPress does offer a very nice, flexible feature set and code that's easy to modify. I haven't played around with Movable Type or other platforms, and there's really no way to tell in advance how any particular platform will hold up under high load. I've been reading a lot about this these past few days, and given the holy wars that routinely rage over topics like this, it's difficult to pick out the signal from the noise. What I'd really want to see is solid evidence in the form of an independent site that does benchmark tests, and I haven't come across anything like that.

Comment by: Ebonmuse | June 21, 2008, 11:09 am

My caution suggests that it isn't WordPress, I have never experienced this on any wordpress site, or at least never when it couldn't be pointed to a data center having internal issues or a server going bad.

Comment by: D.S. | June 21, 2008, 12:38 pm

It's hard for me to tell if it's any better. Just now I had surprisingly little trouble getting on Daylight Atheism. But when I clicked on this thread I waited well over a minute before clicking Stop to try again. When I did, the thread came up within about five seconds. It doesn't make much sense. I've had trouble getting on early in the morning and less during what I would guess should be high traffic times.

Comment by: mikespeir | June 21, 2008, 12:47 pm

Still as slow as it was a couple months or so ago when you first posted about it. I never noticed any increase in loading speed, temporary or not.

Using XP and Firefox, if that means anything.

Comment by: KShep | June 21, 2008, 4:52 pm

What I've been noticing is a delay before I start receiving data; after that happens, the page loads in short order.

This is what I've been noticing as well, for the past few (3-5?) days. I'd say it takes 2-3 minutes to connect, then it goes fine. Today, the front page loaded almost instantly (for dial-up), but then it took a minute or two for this page to connect when I wanted to reply to it. IIRC, the status bar says something along the lines of "Waiting for http://www.daylightatheism.org..." (in Firefox 2.0.0.14 on WinXP Pro SP2) for those few minutes.

Comment by: Nes | June 21, 2008, 5:08 pm

Eh, it did that hyperlink automatically. I didn't have the "http://" part and I had ended it with an ellipsis which got partially hyperlinked...

Comment by: Nes | June 21, 2008, 5:12 pm

I don't know if this is related to the general site slowness, but this is the first time I've been able to access Daylight Atheism for at least a month. I've been getting absolutely no connection (long wait time, then some variant of 404) consistently, though my attempts to access the site have decreased in frequency in the last couple of weeks.

Here's hoping it stays fixed.

Comment by: konrad_arflane | June 22, 2008, 10:37 am

It was a little quicker today than it has been recently, but could that be because it is Sunday and most people are lazing by the pool and having BBQs instead of reading blogs?

Comment by: superhappyjen | June 22, 2008, 12:23 pm

So, I think there may at last have been a breakthrough in this interminable saga.

I spent some time today doing a line-by-line analysis of the code that runs when my site loads, and I think I've pinned down the problem. Ironically, it had to do with a caching module built into WordPress. Just one function was responsible for the vast majority of the time it was taking to load this site's index page. And since my webserver can only hold a limited number of TCP connections open at one time, the problem tends to cascade: a bunch of people connect, and while they're waiting for the index page to load, they're taking up all the available connections for subsequent visitors, who then have to wait in the queue even longer, and so on.

I've removed the call to the misbehaving function, and I think Daylight Atheism is responding a lot better now. Please let me know, readers, if you've observed the same.

Comment by: Ebonmuse | June 22, 2008, 5:20 pm

I've observed a marked increase in performance. Good job clearing that up.

Comment by: OMGF | June 22, 2008, 5:45 pm

Yes, it's much better! Well done!

As I use WP (on a smaller scale) I'd be interested in knowing where the problem was exactly. Have you shared this info on a WordPress forum somewhere?

Comment by: Eshu | June 22, 2008, 6:38 pm

I haven't yet, but I will. For the technically inclined, here are the changes I made:

1. Disable the built-in cron module. At least for me, it was hogging the CPU and causing repeated errors that looked like this:

[client 67.210.98.250] script '/var/www/vhosts/default/htdocs/wp-cron.php' not found or unable to stat

You can fix this by commenting out the call to spawn_cron() around line 135 of wp-includes/cron.php.

2. In wp-settings.php, there's use of the HTTP variables $_SERVER['SCRIPT_NAME'] and $_SERVER["REQUEST_URI"] without checking to see if they're defined. My version of Apache doesn't define them, causing errors every time a page was loaded. Again, I commented out the code that makes reference to those variables.

3. The most significant change, the one I described above, is the call to wp_cache_postload() around line 380 of wp-settings.php. Every invocation of this function was taking between five and ten seconds, sometimes more. I believe this is used by WP's built-in object cache, which I wasn't even using. I took out this call and performance went way up.

Comment by: Ebonmuse | June 22, 2008, 6:45 pm

It has been improving since few days ago and it's much better now. Good job.

Comment by: prase | June 23, 2008, 6:25 am

Wow! It just popped right up! Looks like ya done good, Ebon.

Comment by: mikespeir | June 23, 2008, 11:43 am

Yes, it's going much better now. It was yesterday too, but I wanted to wait before commenting just in case it was a chance event.

Comment by: Nes | June 23, 2008, 8:46 pm

Seems fixed to me. Now I can get my atheistic fix on a regular basis once more.

Comment by: yunshui | June 24, 2008, 9:19 am