500 Internal Server Error on DreamHost VPS

Targets Web
1

I’m accustomed to 500 Internal Server Error’s when neglecting to set the chmod 755 etc., but I’m new to DreamHost and can’t seem to get this going. Before I bang my head for another hour does anyone have experience with DreamHost’s VPS hosting of Web Apps?

I tried creating a simple TEST.cgi and it runs (simply python script). However no matter what I set the architecture to (x86 32-bit, x86 64-bit, etc) I get the same error.

Thanks for any tips!

2

They might not have a pre-requisite library installed on their service. Do you have console access or can you find the info out what they have installed via the working cgi, a phpinfo file or their faq?

See Linux Notes near the end of http://documentation.xojo.com/resources/system_requirements_for_current_version.html for more info, sorry I can’t help more, my linux usage is many many years old, someone who’s more up to speed on these things might be able to help, maybe ask in Targets>Linux ?

3

I’ll paste my progress in here in hopes it might serve as a good resource…

The DreamHost tech support sent me a line from their logs (which I unfortunately cannot access myself), which reads:

[error] [client 000.86.33.36] Can't use an undefined value as a symbol reference at update.cgi line 118.
4

@William Reynolds

I saw lately someone stating that their log file has always had theses errors but was not causing the 500 error

cannot find the post right now :confused:

5

[quote=445613:@William Reynolds]I’ll paste my progress in here in hopes it might serve as a good resource…

The DreamHost tech support sent me a line from their logs (which I unfortunately cannot access myself), which reads:

[error] [client 000.86.33.36] Can't use an undefined value as a symbol reference at update.cgi line 118.

Every Status 500 I see in access.log is associated with that CGI Line 118 in stderr.log. That CGI Line 118 error is a common report in this forum. I find it happening often with mobile users, especially iPhone users. I’m pretty sure there’s a one to one relationship between a stderr.log CGI Line 118 error and an Internal Server Error 500. At least over here.

6

Thanks Julian/Brian/Ralph! After digging around the forum I eventually found a lot of references to ‘line 118’ as well, and the more I dig around the less useful information I find it seems.

I’ve opened a ticket with the hosting company to see if they can give me more info about their server (blocked ports, weird security settings, not-installed libraries, etc.). I’ll continue to bang on this. Thanks to everyone for contributing their two cents!

7

Are you making sure your app is not running when attempting to update it with new files? See this:

http://www.dev.1701software.com/blog/2013/09/08/upgrading-xojo-cgi-apps

8

Excellent point. But yes, in fact I’ve been creating a new file & directory for each subsequent test (tedious).

9

Then you need to use a different AppID for each of these updates, or you will get an Internal Error 500 for each new update.

10

This is the value at ‘Application Identifier’ (under Shared > Build) correct?
Example: com.mydomain.myappname

11

[quote=445650:@William Reynolds]This is the value at ‘Application Identifier’ (under Shared > Build) correct?
Example: com.mydomain.myappname[/quote]
Yes. Every Web app on that server must have a different App ID.

12

One of the things I’ll miss about HostGator is that they have a tool that lets you view and kill running processes. So if I did have a running app that I wanted to replace I could terminate it. But your point is taken. (thanks!)

13

I finally got full access to the error log, and here’s a line that the hosting company neglected to share with me:

[error]  .../cgi-bin/XojoTest: error while loading shared libraries: libunwind.so.8: cannot open shared object file: No such file or directory

…so now I know what to do. If all goes well I’ll post the steps here as they pertain to VPS and DreamHosts system.

14

I think you’ll also find many references to “libunwind.so” on this forum as well.

15

I’m on the cusp of finding a solid solution (or so I lead myself to believe).

Question: Does anyone recommend any of these OS images as ‘ideal’ for hosting Web Apps? (xojo web apps, to be clear)

CentOS-7
CoreOS-Stable
Debian-8
Debian-9
Fedora-25
Fedora-29
Ubuntu-14.04
Ubuntu-16.04
Ubuntu-17.10
Ubuntu-18.04

16

Fedora - NO! it is a bleeding edge release model that will not be stable

Run a Stable release of RHEL (CentOS7) or a Stable release of Debian (Ubuntu 18.04)