Stopping apache on linux

Stopping and Restarting Apache HTTP Server

This document covers stopping and restarting Apache HTTP Server on Unix-like systems. Windows NT, 2000 and XP users should see Running httpd as a Service and Windows 9x and ME users should see Running httpd as a Console Application for information on how to control httpd on those platforms.

See also

Introduction

In order to stop or restart the Apache HTTP Server, you must send a signal to the running httpd processes. There are two ways to send the signals. First, you can use the unix kill command to directly send signals to the processes. You will notice many httpd executables running on your system, but you should not send signals to any of them except the parent, whose pid is in the PidFile . That is to say you shouldn’t ever need to send signals to any process except the parent. There are four signals that you can send the parent: TERM , USR1 , HUP , and WINCH , which will be described in a moment.

To send a signal to the parent you should issue a command such as:

kill -TERM `cat /usr/local/apache2/logs/httpd.pid`

The second method of signaling the httpd processes is to use the -k command line options: stop , restart , graceful and graceful-stop , as described below. These are arguments to the httpd binary, but we recommend that you send them using the apachectl control script, which will pass them through to httpd .

After you have signaled httpd , you can read about its progress by issuing:

tail -f /usr/local/apache2/logs/error_log

Modify those examples to match your ServerRoot and PidFile settings.

Stop Now

Sending the TERM or stop signal to the parent causes it to immediately attempt to kill off all of its children. It may take it several seconds to complete killing off its children. Then the parent itself exits. Any requests in progress are terminated, and no further requests are served.

Graceful Restart

The USR1 or graceful 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.

This code is designed to always respect the process control directive of the MPMs, so the number of processes and threads available to serve clients will be maintained at the appropriate values throughout the restart process. Furthermore, it respects StartServers in the following manner: if after one second at least StartServers new children have not been created, then create enough to pick up the slack. Hence the code tries to maintain both the number of children appropriate for the current load on the server, and respect your wishes with the StartServers parameter.

Users of mod_status will notice that the server statistics are not set to zero when a USR1 is sent. The code was written to both minimize the time in which the server is unable to serve new requests (they will be queued up by the operating system, so they’re not lost in any event) and to respect your tuning parameters. In order to do this it has to keep the scoreboard used to keep track of all children across generations.

The status module will also use a G to indicate those children which are still serving requests started before the graceful restart was given.

At present there is no way for a log rotation script using USR1 to know for certain that all children writing the pre-restart log have finished. We suggest that you use a suitable delay after sending the USR1 signal before you do anything with the old log. For example if most of your hits take less than 10 minutes to complete for users on low bandwidth links then you could wait 15 minutes before doing anything with the old log.

When you issue a restart, a syntax check is first run, to ensure that there are no errors in the configuration files. If your configuration file has errors in it, you will get an error message about that syntax error, and the server will refuse to restart. This avoids the situation where the server halts and then cannot restart, leaving you with a non-functioning server.

This still will not guarantee that the server will restart correctly. To check the semantics of the configuration files as well as the syntax, you can try starting httpd as a non-root user. If there are no errors it will attempt to open its sockets and logs and fail because it’s not root (or because the currently running httpd already has those ports bound). If it fails for any other reason then it’s probably a config file error and the error should be fixed before issuing the graceful restart.

Restart Now

Sending the HUP or restart signal to the parent causes it to kill off its children like in TERM , but the parent doesn’t exit. It re-reads its configuration files, and re-opens any log files. Then it spawns a new set of children and continues serving hits.

Users of mod_status will notice that the server statistics are set to zero when a HUP is sent.

Graceful Stop

The WINCH or graceful-stop 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 will then remove its PidFile and cease listening on all ports. The parent will continue to run, and monitor children which are handling requests. Once all children have finalised and exited or the timeout specified by the GracefulShutdownTimeout has been reached, the parent will also exit. If the timeout is reached, any remaining children will be sent the TERM signal to force them to exit.

A TERM signal will immediately terminate the parent process and all children when in the «graceful» state. However as the PidFile will have been removed, you will not be able to use apachectl or httpd to send this signal.

The graceful-stop signal allows you to run multiple identically configured instances of httpd at the same time. This is a powerful feature when performing graceful upgrades of httpd, however it can also cause deadlocks and race conditions with some configurations.

Care has been taken to ensure that on-disk files such as lock files ( Mutex ) and Unix socket files ( ScriptSock ) contain the server PID, and should coexist without problem. However, if a configuration directive, third-party module or persistent CGI utilises any other on-disk lock or state files, care should be taken to ensure that multiple running instances of httpd do not clobber each other’s files.

You should also be wary of other potential race conditions, such as using rotatelogs style piped logging. Multiple running instances of rotatelogs attempting to rotate the same logfiles at the same time may destroy each other’s logfiles.

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Copyright 2021 The Apache Software Foundation.
Licensed under the Apache License, Version 2.0.

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How do I stop Apache from starting on Linux?

Stop Apache from Starting on Linux

The procedure to stop Apache from starting at boot time on Linux is as follows:

1. Open the terminal application
2. Login using ssh for remote server. For example: ssh user@server-name
3. Use sudo systemctl disable httpd && sudo systemctl stop httpd on RHEL/CentOS/Oracle/Fedora Linux.
4. Ubuntu/Debian users run sudo systemctl disable apache2 && sudo systemctl stop apache2 command.

Let us see all commands and examples in details.

Stop Apache on a CentOS/RHEL/Fedora/Oracle Linux from starting

Is Apache 2 service running? Run the following systemctl command:
sudo systemctl status httpd
Next find out if httpd enabled at boot time:
sudo systemctl is-enabled httpd
If enabled at boot time, disable it, run:
sudo systemctl disable httpd
Stop the service, execute:
sudo systemctl stop httpd
sudo systemctl mask httpd
Verify it:
sudo systemctl status httpd
sudo systemctl is-enabled httpd

The mask option will link httpd unit files to /dev/null, making it impossible to start it. This is a stronger version of disable, since it prohibits all kinds of activation of the unit, including enablement and manual activation. Use this option with care. See Start / Stop and Restart Apache 2 Web Server Command for more info.

A note about Ubuntu/Debian Linux users

The syntax is as follows:
sudo systemctl status apache2
sudo systemctl is-enabled apache2
sudo systemctl disable apache2
sudo systemctl stop apache2
sudo systemctl mask apache2

You can delete the apache2 server package using the apt command/apt-get command:
sudo apt remove apache2

I suggest you read man page of systemctl command, type:
man systemctl
systemctl —help

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CentOS 6.x and Apache Linux AMI stop Apache from starting

Is httpd server running? Run the following service command:
sudo service httpd status
Next find out if httpd enabled at boot time using the chkconfig command:
sudo chkconfig —list httpd
If httpd is enabled at boot time, disable it, run:
sudo chkconfig httpd off
Stop the service, execute:
sudo service httpd stop
Verify it:
sudo service httpd status
sudo chkconfig —list httpd

Commands for CentOS 6 or Amazon Linux AMI

Conclusion

You learned how to stop Apache starting on Linux using various command line options. See Apache 2 home page for more info.

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Start / Stop and Restart Apache 2 Web Server Command

H ow do I restart an Apache 2 Web Server under a Debian / Ubuntu / CentOS / RHEL / Fedora Linux or UNIX-like operating systems? Can you tell me command to start or stop Apache 2 web server running on Linux?

Tutorial details
Difficulty level	Easy
Root privileges	Yes
Requirements	Apache 2 on Linux / Unix
Est. reading time	3 mintues

Apache is primarily used to serve both static content and dynamic Web pages on the World Wide Web. Many web applications are designed expecting the environment and features that Apache provides. Apache can be started or restarted using any one of the following methods on Linux or Unix-like systems.

First, login to your web-server using ssh client, if server is not in your local data center:
ssh root@your.server.com
Once logged in type the following commands as per your Linux or Unix variant.

Debian/Ubuntu Linux Specific Commands to Start/Stop/Restart Apache

You can either use service or /etc/init.d/ command as follows on Debian Linux version 7.x or Ubuntu Linux version Ubuntu 14.10 or older:

Restart Apache 2 web server, enter:

# /etc/init.d/apache2 restart
OR
$ sudo /etc/init.d/apache2 restart
OR
$ sudo service apache2 restart

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To stop Apache 2 web server, enter:

# /etc/init.d/apache2 stop
OR
$ sudo /etc/init.d/apache2 stop
OR
$ sudo service apache2 stop

To start Apache 2 web server, enter:

# /etc/init.d/apache2 start
OR
$ sudo /etc/init.d/apache2 start
OR
$ sudo service apache2 start

A note about Debian/Ubuntu Linux systemd users

Use the following systemctl command on Debian Linux version 8.x+ or Ubuntu Linux version Ubuntu 15.04+ or above:
## Start command ##
systemctl start apache2.service
## Stop command ##
systemctl stop apache2.service
## Restart command ##
systemctl restart apache2.service
We can view status using the following command:
$ sudo systemctl status apache2.service

CentOS/RHEL (Red Hat) Linux version 4.x/5.x/6.x or older specific commands

## Start ##
service httpd start
## Stop ##
service httpd stop
## Restart ##
service httpd restart

CentOS/RHEL (Red Hat) Linux version 7.x or newer specific commands

Most modern distro now using systemd, so you need to use the following systemctl command:
## Start command ##
systemctl start httpd.service
## Stop command ##
systemctl stop httpd.service
## Restart command ##
systemctl restart httpd.service

Alpine Linux start / stop / restart Apache 2 using openrc

We need to use the service command as root user:
# service apache2 start
# service apache2 stop
# service apache2 status
# service apache2 restart
Session:

FreeBSD Unix users

FreeBSD user can restart Apache as follows:
# /usr/local/etc/rc.d/apache22 restart
# service restart apache22
# service stop apache22
# service start apache22

Generic method to start/stop/restart Apache on a Linux/Unix

The syntax is as follows (must be run as root user):
## stop it ##
apachectl -k stop
## restart it ##
apachectl -k restart
## graceful restart it ##
apachectl -k graceful
## Start it ##
apachectl -f /path/to/your/httpd.conf
apachectl -f /usr/local/apache2/conf/httpd.conf

Summing up

You learned how to start, stop or restart the Apache 2 web server using command-line over ssh-based session.

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