Passenger Crash Troubleshooting on CloudLinux Servers

The Passenger crash logs can fill up /tmp very quickly, which could affect Apache/MySQL services. Here are the steps that you can check if you notice Passenger-related crash logs on your server.

1. Update the Passenger package to the latest stable version.

   On non-cPanel servers:

   # yum update alt-mod-passenger

   On WHM/cPanel servers with EasyApache 4:

   # yum update ea-apache24-mod-alt-passenger

2. Check the package's integrity via: 

   rpm -V <rpm_name>

   On WHM/cPanel servers we can check RPMs by running:

   /scripts/find_and_fix_rpm_issues

3. Restart the Apache service if you've updated the Passenger.
4. On WHM/cPanel server with CageFS, make sure that the Shell Fork Bomb protection is disabled. Worry not, CageFS has built-in protection, you don't have to keep both. Once disabled, update CageFS via:

   cagefsctl --force-update

If the issue is not solved and Passenger apps proceed to crash

1. Check the recent crash log file /tmp/passenger-crash-log.xxxxxx/backtrace.log - usually, it will point you in the right direction. For example:
   

   # less /tmp/passenger-crash-log.1558095432.PUj710/backtrace.log
   *** ERROR ***: 'gdb' not found. Please install it (and if using Nginx ensure that PATH isn't filtered out, see also its "env" option).

   Install the missing RPM; if it's installed already, reinstall the package. In the example above, that would be:

   #yum install gdb
   ##If the package is already installed:
   #yum reinstall gdb

2. Most of the time, we saw that Passenger crash cause either:

• A corrupted glibc package;
• The glibc package was installed from the 3rd-party repository instead of the CloudLinux repo.

In both cases, try to reinstall the package; that should help.

# rpm -V glibc
//if the package is corrupted, reinstall one:
# yum reinstall glibc

# rpm -qi glibc
//if the package has not CloudLinux Vendor, then upgrade/downgrade it from CL repo. For example, on CloudLinux 7 server we can run:
# yum downgrade glibc glibc-common glibc-headers glibc-devel nscd glibc-static --disablerepo=* --enablerepo=cloudlinux-x86_64-server-7