500 Internal Server Error- FastCGI: incomplete headers (0 bytes) received from server

[Dave.T]

Hello,

Thanks in advance for any help. On occasion when entering Admin, and sometimes during the customer checkout process, a "500 Internal Server Error" page will be returned. I found a correlation to these errors in the Apache error log. The error is as follows:

[Wed Oct 15 01:53:37 2008] [error] [client xx.xx.xx.xxx] FastCGI: incomplete headers (0 bytes) received from server "/home/content/....omitted.../html-x-httpd-php"

I am unable to access mySQL logs to look for correlated entries.

Anyone have a clue? Thanks!

[kuroi]

I recommend reviewing this thread.

[talk2kmf]

I am getting this 500 Internal Server error also, very sporadically when either deleting an item from the shopping cart, updating quantities, clicking on the Checkout button, or later changing the address in the Checkout page. The error typically happens about 20-30 minutes after I start testing the shopping cart and shipping options but that could just be coincidental.

The log shows the same error:

[FONT="Courier New"]FastCGI: incomplete headers (0 bytes) received from server "/var/chroot/home/content/<myusrdirectory>/html-x-httpd-php"[/FONT]

I've been using a sub-domain for zencart, with the correct configurations in the config file. As far as I can tell the permissions are set correctly (although I don't have shell access).

Functionally, everything else seems to work fine. Also, when the error does occur, reloading the page continues the operation fine (for another 20-30 minutes of testing).

One final note, in order to show a customized "Please reload this page" message I created a webpage called "error500.shtml" and put it in the zencart root directory. I then added a .htaccess file to the zencart root directory with the following line:

ErrorDocument 500 /error500.shtml

At least now if a customer gets this error they will get a friendly request to just reload the page. But ideally I'd like to get the error fixed.

Any suggestions would be appreciated. Thanks!

KMF

[kuroi]

The tip for creating a custom error 500 page is very helpful.

As to the error itself, this doesn't sound like it's anything to do with how you have Zen Cart configured. The error message is coming straight from your server (not the PHP parser which is where Zen Cart errors tend to be picked up) and suggests a more fundamental problem with how PHP itself is configured or your server's ability to handle it without timing out.

There are a few folks in the community who know a lot about hosting and servers and hopefully one of them will happen by with some insight, but the first port of call really needs to be your web host.

[Website Rob]

In these type situations it's always best to clarify if things were working OK and, either a change was made or no change was made, before the problem started. Many times we makes changes; add a Mod, change paths in the config files, etc. and think nothing of it. There are also times when the Hoster will make changes and not notify Clients; which is very common because usually they do not need notice.

The cause of this particular problem is directly related to FastCGI and how it is setup on the Server. Could be anything from session/cache control; yours or the Servers, mySQL, corrupt file, and so.

This 'quicky' may or may not help.

Add this line to the top of your main .htaccess file.
AddHandler fastcgi-script .fcgi

Otherwise, best to contact your Hoster as only they can help sort out this type of problem.

[talk2kmf]

Thanks for the suggestions. I tried adding the AddHandler line to .htaccess but the error appeared almost immediately.

I had not noticed this error until I started testing the shipping modules. I cloned a few and installed the Staticlist mod. I think the error appeared before I installed the mod but I don't recall.

Over the past few days the error occurred when I was testing the shipping and checkout but today it happened when I tried to log in, so it may not be specific to shopping cart processing.

Unfortunately, we're hosted on GoDaddy and their support is useless.
For example, I asked about creating a custom 500 error page and they told me it wasn't possible. Fortunately I found this page:
http://www.codestyle.org/sitemanager...#apache-config

When I asked for help with this FastCGI error, they said I can either use their own webcart product or buy a dedicated server account. They refuse to admit it could be anything their server is doing and blame Zen Cart coding.

KMF

[Website Rob]

Time to shop around for a new Host as it seems GoDaddy cannot or will not fix your problems... which they seemed to have created.

[talk2kmf]

I did manage to find a work-around, for now. I edited the error page to say "System Processing..." and then reload the page automatically by using a meta refresh=5 seconds tag. Here's what my error500.shtml has in it:

<html>
<head>
<meta http-equiv="refresh" content="5">
<title>System Processing 500</title>
<meta http-equiv="Content-Type" content="text/html; charset=iso-8859-1">
</head>
<body>
<p><center><H2>The system is processing your request. 
Please wait...</H2><p>If this message lasts for more than 30
seconds, please click the back button on your browser and try
again.</center>
</body>
</html>

Since the browser doesn't "see" the error page thrown up by the server it reloads the page it was supposed to bring up in the first place. I've tested it in Firefox 3 and Explorer 6 and it seems to work.

Note the .htaccess file is in the zencart sub-directory but the error page specified in the .htaccess file as " /error500.shtml " has to be in the system root directory. Otherwise you'll get a 404 at the end of the Internal Server Error message.

KMF

[yellow1912]

The main point is: the 500 error is unacceptable, it interferes with your customers shopping experience. Rewording the error message doesnt solve the problem.

[talk2kmf]

This might be another clue. Along with the error:

[FONT="Courier New"]FastCGI: incomplete headers (0 bytes) received from server "/var/chroot/home/content/<myusrdirectory>/html-x-httpd-php"[/FONT]

I've now also got:

[FONT="Courier New"](104)Connection reset by peer: FastCGI: comm with server "/var/chroot/home/content/<myusrdirectory>/html-x-httpd-php" aborted: read failed[/FONT]

In addition, I'm noticing the error more often with Internet Explorer (~ every 10min) than with Firefox (~ 20-30minutes). The main difference I've seen between the two is that IE is faster loading pages. My guess is that IE maybe using more cache or it may process more quickly on the client side and is running into whatever is on the server causing the error more often than Firefox.

Any more debugging suggestions would be appreciated. Thanks!

KMF