| Tutorial details | |
|---|---|
| Difficulty level | Easy |
| Root privileges | Yes |
| Requirements | apachectl/service/systemctl command on Linux/Unix |
| Est. reading time | 1 minute |
- start
- restart
- graceful
- stop
- graceful-stop
A note about graceful Apache webserver restart
You need to send USR1 signal to the Apache server:
This (USR1) signal causes the parent process to advise the children to exit after their current request (or to exit immediately if they’re not serving anything). The parent re-reads its configuration files and re-opens its log files. As each child dies off the parent replaces it with a child from the new generation of the configuration, which begins serving new requests immediately.
We can run a configuration file syntax test as follows:
apachectl configtest
apachectl -t
Related: 21 Examples To Make Sure Unix / Linux Configuration Files Are Free From Syntax Errors
Command syntax to gracefully restart the Apache 1.x/2.x after changing config file
Type the following command as a root user:
apachectl -k graceful
OR
apache2ctl -k graceful
Apache 2 Reload HTTPD Configuration File Without Restarting Apache When Using Systemd
The syntax is:
# CentOS/RHEL/Fedora Linux
sudo systemctl reload httpd
# Debian/Ubuntu Linux
sudo systemctl reload apache2
Reloading Apache web server config without restarting it
Older Linux disro commands to reload Apache server
You can also use Linux distro specific Sys V init script as follows to gracefully reload the server. The following example works on RHEL/CentOS Linux and friends only:
/etc/init.d/httpd graceful
OR
/sbin/service httpd graceful
Debian / Ubuntu Linux and friends use the following syntax:
/etc/init.d/apache2 reload
Monitoring apache progress
After you have signaled Apache 2, you can read apache error_log file about its progress by issuing the following tail command:
## For RHEL / CentOS and friends ## tail -f /var/log/httpd/error_log ## For Debian / Ubuntu and friends ## tail -f /var/log/apache2/error.log ## FreeBSD Unix ## tail -f /var/log/httpd-error.log
Conclusion
You learned how to reload Apache 2 web server gracefully without restating it fully. In summary, we test for config files for error and then reload them:
apachectl configtest
apachectl -k graceful
| apachectl command | Description |
|---|---|
| -D name | define a name for use in directives |
| -d directory | specify an alternate initial ServerRoot |
| -f file | specify an alternate ServerConfigFile |
| -C "directive" | process directive before reading config files |
| -c "directive" | process directive after reading config files |
| -e level | show startup errors of level (see LogLevel) |
| -E file | log startup errors to file |
| -v | show version number |
| -V | show compile settings |
| -h | list available command line options (this page) |
| -l | list compiled in modules |
| -L | list available configuration directives |
| -t -D DUMP_VHOSTS | show parsed vhost settings |
| -t -D DUMP_RUN_CFG | show parsed run settings |
| -S | a synonym for -t -D DUMP_VHOSTS -D DUMP_RUN_CFG |
| -t -D DUMP_MODULES | show all loaded modules |
| -M | a synonym for -t -D DUMP_MODULES |
| -t -D DUMP_INCLUDES | show all included configuration files |
| -t | run syntax check for config files |
| -T | start without DocumentRoot(s) check |
| -X | debug mode (only one worker, do not detach) |
🐧 4 comments so far... add one ↓
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Thanks for the helpful information. How would the graceful restart work if I have a password protected SSL Certificate and must type in a password every time I restart Apache?
I would suggest checking the integrity of the modified config file before issuing the graceful restart. Without checking, your HTTPD server could stop running if it tries to load a config file with a syntax error.
apachectl configtest
then
apachectl graceful (The -k isn’t necessary)
how we can do the same in Windows ?
@liamg: Are you asking this on a portal that is dedicated to Linux ?