Issue Problems with mod proxy_fcgi

[Tam Nguyen]

I've been battling this for quite a few hours, and I've concluded that the error I'm getting has to do with proxy_fcgi, which is baked into apache 2.4.6.

When I visit this page https://headshotcrew.com/maurice-jager, I'd get the 500 response intermittently. Sometimes, the page actually loads even though Chrome tells me the server responded with 500.

Here's the error I get in my per-site error logs:

./error_log:[Wed Jul 05 22:59:18.614924 2017] [proxy_fcgi:error] [pid 27324:tid 140188772710144] [client 196.52.2.65:48576] Premature end of script headers: index.php, referer: https://headshotcrew.com/maurice-jager
./error_log:[Wed Jul 05 22:59:18.614984 2017] [proxy_fcgi:error] [pid 27324:tid 140188772710144] [client 196.52.2.65:48576] AH01070: Error parsing script headers, referer: https://headshotcrew.com/maurice-jager

And here's the error I get in modsec_audit.log

--b00da07e-A--
[06/Jul/2017:00:05:30 --0400] WV23CtsjLirjwJW7-V7nYgAAAAI 74.208.174.211 55376 74.208.174.211 7081
--b00da07e-B--
GET /maurice-jager HTTP/1.0
Host: headshotcrew.com
X-Real-IP: 196.52.2.65
X-Accel-Internal: /internal-nginx-static-location
Connection: close
cache-control: max-age=0
user-agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/60.0.3112.50 Safari/537.36
upgrade-insecure-requests: 1
accept: text/html,application/xhtml+xml,application/xml;q=0.9,image/webp,image/apng,*/*;q=0.8
dnt: 1
accept-encoding: gzip, deflate, br
accept-language: en-US,en;q=0.8,vi;q=0.6
cookie: SSESS002befecc02cd852f25fc2285a18c45e=tBVzfRxHuSdo2ltUBfA4i6svw9_HRDxp0MDTOEqR4vA; has_js=1

--b00da07e-F--
HTTP/1.1 500 Internal Server Error
X-Content-Type-Options: nosniff

--b00da07e-E--

--b00da07e-H--
Apache-Error: [file "util_script.c"] [line 455] [level 3] %s: %s
Apache-Error: [file "mod_proxy_fcgi.c"] [line 756] [level 3] AH01070: Error parsing script headers
Apache-Error: [file "mod_proxy_fcgi.c"] [line 688] [level 3] AH01068: Got bogus version %d
Apache-Error: [file "mod_proxy_fcgi.c"] [line 914] [level 3] [status 22] AH01075: Error dispatching request to %s:
Apache-Handler: proxy:unix:///var/www/vhosts/system/headshotcrew.com/php-fpm.sock|fcgi://127.0.0.1:9000
Stopwatch: 1499313930054033 531053 (- - -)
Stopwatch2: 1499313930054033 531053; combined=9, p1=2, p2=5, p3=0, p4=0, p5=2, sr=0, sw=0, l=0, gc=0
Response-Body-Transformed: Dechunked
Producer: ModSecurity for Apache/2.9.0 (http://www.modsecurity.org/).
Server: Apache
Engine-Mode: "ENABLED"

--b00da07e-Z--

From what I can gather, even one from this forum (Issue - AH01068: Got bogus version 32), I'm screwed unless I upgrade my Apache. Am I screwed? Is there another way? If not, how do I upgrade Apache? I'm running Plesk Onyx 17.5.3 and CentOS Linux 7.3.1611.

Edit: apparently 2.4.6 is what's supported Apache httpd versions supported in Red Hat Enterprise Linux - Red Hat Customer Portal

Thanks!

 

[UFHH01]

Hi Tam Nguyen,

I'm screwed unless I upgrade my Apache

Correct.

Am I screwed?

Yes.

Is there another way?

If you don't desire to compile apache by yourself, you only have the possibilities to upgrade with additional sources/repos ( but pls. note, that you could experience issues/errors/problems, if the used apache version is not declared as "supported" at the Plesk documentation:

=> Software Requirements for Plesk​

 

[Bitpalast]

In my opinion it's not a proxy_fcgi error, but a PHP script error.
"Premature end of script headers: index.php"
is a clear indication that the script is not running correctly. This can be caused by a certain start condition or variables. Maybe some environment variables that are needed are not filled. Maybe the script sends a PHP header() but does not put anything into it. Difficult to say, but almost certainly there is something wrong with the script. It is easy to test: Create a <?php phpinfo() ?> script file and request that over and over again. You probably will not be able to reproduce the error with it.

 

[Tam Nguyen]

In my opinion it's not a proxy_fcgi error, but a PHP script error.
"Premature end of script headers: index.php"
is a clear indication that the script is not running correctly. This can be caused by a certain start condition or variables. Maybe some environment variables that are needed are not filled. Maybe the script sends a PHP header() but does not put anything into it. Difficult to say, but almost certainly there is something wrong with the script. It is easy to test: Create a <?php phpinfo() ?> script file and request that over and over again. You probably will not be able to reproduce the error with it.

It's just Drupal with a few profiles on the site. We didn't cook up anything crazy ourselves.

I guess it's time to rollback, and say goodbye to Plesk. I was actually having problems with Plesk taking a full minute for each page to load in the GUI too, and it was driving me insane.

Thanks you guys.

 

[Tam Nguyen]

Also, the site worked on the old server with the exact same code, so it's definitely something with the new Apache and its mod(s).

 

[Bitpalast]

As the GUI is controlled and delivered completely separate from the regular Nginx/Apache configuration of your websites, a slow GUI is a different topic.