# Fix Apache Child Process Exit Score 3221225477 Crash

Apache child processes crash unexpectedly with exit score 3221225477, causing intermittent 503 errors and service degradation. The error log shows:

bash
[Thu Apr 08 11:30:22.654321 2026] [mpm_winnt:notice] [pid 4567] AH00362: Child: Waiting 30 more seconds for 3 worker threads to finish.
[Thu Apr 08 11:30:52.654322 2026] [mpm_winnt:notice] [pid 4567] AH00363: Child: Terminating 3 threads that failed to exit.
[Thu Apr 08 11:30:52.654323 2026] [mpm_winnt:notice] [pid 4567] AH00428: Child: process 4568 exit signal Access violation (0xC0000005), possible coredump in C:/Apache24

Exit code 3221225477 (0xC0000005) is a Windows access violation -- the process attempted to read or write protected memory. On Linux, the equivalent is exit code 139 (SIGSEGV).

Understanding the Exit Code

The exit score 3221225477 converts to hexadecimal as 0xC0000005, which is the Windows NTSTATUS code STATUS_ACCESS_VIOLATION. This means a module loaded into the Apache process attempted to access invalid memory. On Linux systems, you would see:

bash
[Thu Apr 08 11:30:22.654321 2026] [core:notice] [pid 1234] AH00052: child pid 5678 exit signal Segmentation fault (11)

Common Causes

1. Incompatible Third-Party Modules

A recently installed or updated Apache module (mod_security, mod_pagespeed, etc.) contains a memory bug:

bash
apache2ctl -M | sort

Compare the loaded modules against your known-working configuration. Temporarily disable recently added modules:

bash
sudo a2dismod pagespeed
sudo systemctl restart apache2

If the crashes stop, the disabled module is the culprit.

2. PHP Extension Memory Corruption

If running PHP as an Apache module (mod_php), a buggy PHP extension can crash the entire Apache process:

bash
php -m | grep -i loaded
php -r "phpinfo();" | grep "PHP Extension"

Check the PHP error log for warnings before the crash:

bash
tail -100 /var/log/php_errors.log

Common culprits: outdated xdebug versions, incompatible ioncube loaders, and memory-unsafe custom extensions.

3. mod_security False Positive Crashing

An overly aggressive mod_security rule can trigger a crash in the regex engine when processing specific request patterns:

apache
# Temporarily disable mod_security to test
SecRuleEngine Off

If crashes stop, re-enable with a higher debug level:

apache
SecRuleEngine On
SecDebugLogLevel 9
SecDebugLog /var/log/apache2/modsec_debug.log

Reproduce the crash and check the debug log for the specific rule that triggers it.

Step-by-Step Diagnosis

Enable Core Dumps (Linux)

bash
# In Apache's systemd override
sudo systemctl edit apache2

Add:

bash
[Service]
LimitCORE=infinity

Then configure core dump location:

bash
echo "/tmp/core.%e.%p" | sudo tee /proc/sys/kernel/core_pattern

After a crash, analyze the core dump:

bash
gdb /usr/sbin/apache2 /tmp/core.apache2.1234
(gdb) bt
(gdb) info registers

The backtrace (bt) shows exactly which function and module caused the crash.

Windows Event Log (Windows)

On Windows, check the Application event log:

powershell
Get-EventLog -LogName Application -Source "Application Error" -Newest 5 | Format-List

Look for the faulting module name -- it will identify which DLL caused the access violation.

Prevention Strategies

Keep Modules Updated

```bash # Debian/Ubuntu sudo apt update && sudo apt upgrade apache2 libapache2-mod-php

# RHEL/CentOS sudo yum update httpd mod_ssl ```

Use PHP-FPM Instead of mod_php

Running PHP as a separate process (PHP-FPM) via mod_proxy_fcgi isolates PHP crashes from Apache:

apache
<FilesMatch \.php$>
    SetHandler "proxy:fcgi://127.0.0.1:9000"
</FilesMatch>

When PHP crashes, only the PHP-FPM worker process dies -- Apache continues serving other requests normally.

Monitor Crash Frequency

bash
grep -c "exit signal" /var/log/apache2/error.log

If crashes are increasing in frequency, investigate immediately. A single crash may be a rare edge case; repeated crashes indicate a systemic issue.