---
id: a17934e4-2fde-4877-82e8-37407643cabc
---

# Apache Restart Incident
---

An Apache restart incident refers to a situation where the Apache web server has been restarted, which may cause a temporary outage or disruption to a web service. This type of incident can occur due to a variety of reasons, such as software updates, configuration changes, or hardware failures. The incident may require immediate attention from a technical specialist to diagnose and resolve the issue to minimize the impact on end-users.

### Parameters
```shell
# Environment Variables


export APACHE_URL="PLACEHOLDER"
```

## Debug

### Check Apache status
```shell
systemctl status apache2.service
```

### Check Apache error logs
```shell
tail -n 50 /var/log/apache2/error.log
```

### Check Apache access logs
```shell
tail -n 50 /var/log/apache2/access.log
```

### Check Apache configuration file syntax errors
```shell
apachectl -t
```

### Check if port 80 is open
```shell
sudo netstat -tuln | grep ":80"
```

### Check server resource usage
```shell
top
```

### Check server disk usage
```shell
df -h
```

### Check server memory usage
```shell
free -m
```

### Check server uptime
```shell
uptime
```

### Resource Constraints: If the server running Apache is running low on memory, CPU, or disk space, Apache may fail to respond, requiring a restart.
```shell


#!/bin/bash



# Check memory usage

total_mem=$(free -m | awk '/^Mem:/{print $2}')

used_mem=$(free -m | awk '/^Mem:/{print $3}')

free_mem=$(free -m | awk '/^Mem:/{print $4}')

mem_percent=$(echo "scale=2; $used_mem/$total_mem * 100" | bc)



if (( $(echo "$mem_percent > 90" | bc -l) )); then

    echo "Memory usage is high (currently using ${used_mem}M out of ${total_mem}M)"

fi



# Check CPU usage

cpu_percent=$(top -bn1 | grep "Cpu(s)" | awk '{print $2 + $4}')

if (( $(echo "$cpu_percent > 90" | bc -l) )); then

    echo "CPU usage is high (currently using ${cpu_percent}%)"

fi

# Check disk space usage

total_disk=$(df -h | awk '$NF=="/"{printf "%d", $2}')

used_disk=$(df -h | awk '$NF=="/"{printf "%d", $3}')

free_disk=$(df -h | awk '$NF=="/"{printf "%d", $4}')

disk_percent=$(df -h | awk '$NF=="/"{print $5}' | sed 's/%//g')

if (( $(echo "$disk_percent > 90" | bc -l) )); then

    echo "Disk space usage is high (currently using ${disk_percent}%)"

fi

# Check Apache status

apache_status=$(systemctl status apache2 | grep "Active:" | awk '{print $2}')

if [ "$apache_status" != "active" ]; then

    echo "Apache is not running (status: ${apache_status})"

fi


```

## Repair

### Verify that all dependencies and libraries required by Apache are installed and up to date. Update any outdated packages if necessary.
```shell


#!/bin/bash

# Update the package list and upgrade outdated packages

sudo apt-get update

sudo apt-get upgrade

# Verify that Apache dependencies and libraries are installed

if [ ! -f /etc/apache2/apache2.conf ]; then

    echo "Apache is not installed"

    exit 1

fi

# Check that all required modules are enabled

if [ ! -f /etc/apache2/mods-enabled/rewrite.load ]; then

    sudo a2enmod rewrite

fi

if [ ! -f /etc/apache2/mods-enabled/ssl.load ]; then

    sudo a2enmod ssl

fi

# Restart Apache to apply changes

sudo systemctl restart apache2

echo "Apache has been successfully remediated"


```

### Test the restart manually to ensure that the Apache server is running correctly.
```shell
bash

#!/bin/bash

# Restart Apache server

systemctl restart apache2

# Test the restart

curl -I ${APACHE_URL}

# Check the HTTP status code

if [ "$?" -ne 0 ]; then

  echo "Apache server is not running correctly."

else

  echo "Apache server is running correctly."

fi

```

An Apache restart incident refers to a situation where the Apache web server has been restarted, which may cause a temporary outage or disruption to a web service. This type of incident can occur due to a variety of reasons, such as software updates, configuration changes, or hardware failures. The incident may require immediate attention from a technical specialist to diagnose and resolve the issue to minimize the impact on end-users.


Tomcat Server Crash incident type refers to a situation where the Tomcat Server, an open-source web server and servlet container, becomes unresponsive and stops functioning. This can result in a complete or partial system outage, leading to a disruption in the delivery of web applications and services. The root cause of the crash can be attributed to a variety of factors such as misconfiguration, network or hardware issues, software bugs, or excessive server load. It is critical to address this incident quickly to minimize the impact on users and restore normal system functionality.


Tomcat Server Crash

The Slowloris Attack is a type of Denial of Service (DoS) attack that exploits a vulnerability in the Apache web server. It works by sending HTTP requests to the server and keeping those connections open for as long as possible, thereby using up all the available resources of the server and rendering it unresponsive to legitimate requests. As a result, the server becomes slow or unresponsive, causing downtime for the affected website or service. This type of attack can be detected and mitigated by implementing specific security measures and tools.


Slowloris Attack Detected on Apache server.

This incident type refers to a problem with the load balancing functionality of the Apache HTTP server when using the mod\_jk connector. This can cause issues with distributing incoming traffic across multiple servers, resulting in reduced performance or even downtime for the affected services. It is important to address and resolve these issues as quickly as possible to minimize impact on users and ensure the stability of the system.


Mod_jk Load Balancing Issues in Apache HTTP.

This incident type refers to a situation where the number of child processes created by an Apache server reaches a high threshold, causing performance issues and potentially leading to server crashes. This can occur due to factors such as high traffic volume or misconfigured server settings. The incident requires investigation and mitigation to restore normal server functioning and prevent future occurrences.


High Number of Apache Child Processes Incident

This incident type refers to a situation where the Apache server is under high load due to busy workers, which may result in slow or unresponsive websites. This can occur when the number of workers reaches the maximum limit or when a large number of requests are being processed simultaneously. This incident requires immediate attention to avoid any negative impact on the website's performance.


High Apache Workers Load

```shell
# Environment Variables


export APACHE_URL="PLACEHOLDER"
```


### Check Apache status

```shell
systemctl status apache2.service
```

### Check Apache error logs

```shell
tail -n 50 /var/log/apache2/error.log
```

### Check Apache access logs

```shell
tail -n 50 /var/log/apache2/access.log
```

### Check Apache configuration file syntax errors

```shell
apachectl -t
```

### Check if port 80 is open

```shell
sudo netstat -tuln | grep ":80"
```

### Check server resource usage

```shell
top
```

### Check server disk usage

```shell
df -h
```

### Check server memory usage

```shell
free -m
```

### Check server uptime

```shell
uptime
```

### Resource Constraints: If the server running Apache is running low on memory, CPU, or disk space, Apache may fail to respond, requiring a restart.

```shell


#!/bin/bash



# Check memory usage

total_mem=$(free -m | awk '/^Mem:/{print $2}')

used_mem=$(free -m | awk '/^Mem:/{print $3}')

free_mem=$(free -m | awk '/^Mem:/{print $4}')

mem_percent=$(echo "scale=2; $used_mem/$total_mem * 100" | bc)



if (( $(echo "$mem_percent > 90" | bc -l) )); then

    echo "Memory usage is high (currently using ${used_mem}M out of ${total_mem}M)"

fi



# Check CPU usage

cpu_percent=$(top -bn1 | grep "Cpu(s)" | awk '{print $2 + $4}')

if (( $(echo "$cpu_percent > 90" | bc -l) )); then

    echo "CPU usage is high (currently using ${cpu_percent}%)"

fi

# Check disk space usage

total_disk=$(df -h | awk '$NF=="/"{printf "%d", $2}')

used_disk=$(df -h | awk '$NF=="/"{printf "%d", $3}')

free_disk=$(df -h | awk '$NF=="/"{printf "%d", $4}')

disk_percent=$(df -h | awk '$NF=="/"{print $5}' | sed 's/%//g')

if (( $(echo "$disk_percent > 90" | bc -l) )); then

    echo "Disk space usage is high (currently using ${disk_percent}%)"

fi

# Check Apache status

apache_status=$(systemctl status apache2 | grep "Active:" | awk '{print $2}')

if [ "$apache_status" != "active" ]; then

    echo "Apache is not running (status: ${apache_status})"

fi


```


### Verify that all dependencies and libraries required by Apache are installed and up to date. Update any outdated packages if necessary.

```shell


#!/bin/bash

# Update the package list and upgrade outdated packages

sudo apt-get update

sudo apt-get upgrade

# Verify that Apache dependencies and libraries are installed

if [ ! -f /etc/apache2/apache2.conf ]; then

    echo "Apache is not installed"

    exit 1

fi

# Check that all required modules are enabled

if [ ! -f /etc/apache2/mods-enabled/rewrite.load ]; then

    sudo a2enmod rewrite

fi

if [ ! -f /etc/apache2/mods-enabled/ssl.load ]; then

    sudo a2enmod ssl

fi

# Restart Apache to apply changes

sudo systemctl restart apache2

echo "Apache has been successfully remediated"


```

### Test the restart manually to ensure that the Apache server is running correctly.

```shell
bash

#!/bin/bash

# Restart Apache server

systemctl restart apache2

# Test the restart

curl -I ${APACHE_URL}

# Check the HTTP status code

if [ "$?" -ne 0 ]; then

  echo "Apache server is not running correctly."

else

  echo "Apache server is running correctly."

fi

```


Apache Restart Incident

Overview

Parameters

Debug

Check Apache status

Check Apache error logs

Check Apache access logs

Check Apache configuration file syntax errors

Check if port 80 is open

Check server resource usage

Check server disk usage

Check server memory usage

Check server uptime

Resource Constraints: If the server running Apache is running low on memory, CPU, or disk space, Apache may fail to respond, requiring a restart.

Repair

Verify that all dependencies and libraries required by Apache are installed and up to date. Update any outdated packages if necessary.

Test the restart manually to ensure that the Apache server is running correctly.

Learn more

Related Runbooks

Tomcat Server Crash

Slowloris Attack Detected on Apache server.

Mod_jk Load Balancing Issues in Apache HTTP.

High Number of Apache Child Processes Incident

Support