Strace PHP
Stracing PHP is a powerful debugging tool to monitor what a script or site is doing in real-time, including detecting bugs, hangs, or other issues.
Steps to Strace PHP
-
Switch to the Website's Environment
- Use the following command to switch to the PHP process user:
Replacesu - [user]
[user]
with the username associated with the website.
- Use the following command to switch to the PHP process user:
-
Identify PHP Processes
- Run the following to list all processes for the user:
Note the Process ID (PID) of the PHP process you want to trace.ps aux
- Run the following to list all processes for the user:
-
Attach Strace to the Process
- Attach
strace
to the identified PHP process using:
Replacestrace -p [process_id]
[process_id]
with the PID from the previous step.
- Attach
Output Insights
The strace output will show:
- System Calls: Track calls to resources like files, databases, or external APIs.
- Delays: Identify where the process is hanging or waiting.
- Errors: Detect system-level errors affecting script execution.
Use Case
Strace is particularly helpful when:
- A PHP script is unresponsive.
- Database or network connections are failing.
- Unexpected resource behavior is occurring.