---
id: a171f957-7330-4c50-9e5d-926e70b7ee93
---

# High Apache Workers Load
---

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.

### Parameters
```shell
# Environment Variables

export APACHE_CONFIG_FILE="PLACEHOLDER"

export PATH_TO_APACHE_CONFIG_FILE="PLACEHOLDER"

export DESIRED_NUMBER_OF_WORKERS="PLACEHOLDER"

export MEMORY_LIMIT="PLACEHOLDER"
```

## Debug

### Check the Apache worker status
```shell
systemctl status apache2
```

### Check the number of Apache workers
```shell
ps aux | grep apache2 | grep -v grep | wc -l
```

### Check the Apache server load
```shell
 apachectl status
```

### Check the Apache server log for errors
```shell
tail -f /var/log/apache2/error.log
```

### Check the server access log for traffic
```shell
tail -f /var/log/apache2/access.log
```

### Check the Apache server configuration file for the maximum worker setting
```shell
grep -i 'MaxRequestWorkers' ${APACHE_CONFIG_FILE}
```

### Check the Apache server configuration file for the current worker setting
```shell
grep -i 'MaxClients' ${APACHE_CONFIG_FILE}
```

### A misconfiguration in the Apache server settings that may cause an imbalance in the load distribution among different workers, leading to an overload on some workers.
```shell


#!/bin/bash

# Check if Apache is installed

if ! command -v apache2 &> /dev/null

then

    echo "Apache is not installed"

    exit

fi

# Check if Apache is running

if ! systemctl is-active --quiet apache2

then

    echo "Apache is not running"

    exit

fi

# Check if Apache configuration is valid

if ! apachectl configtest

then

    echo "Apache configuration is invalid"

    exit

fi

# Check if Apache worker settings are balanced

if [ $(grep -c "BalancerMember" ${PATH_TO_APACHE_CONFIG_FILE}) -lt 2 ]

then

    echo "Apache worker settings are not balanced"

    exit

fi

echo "Apache server is running and workers are balanced"

```

## Repair

### Define variables
```shell
APACHE_CONFIG_FILE=${PATH_TO_APACHE_CONFIG_FILE}

WORKERS_COUNT=${DESIRED_NUMBER_OF_WORKERS}
```

### Update Apache config file
```shell
sed -i "s/MaxRequestWorkers *[0-9]*/MaxRequestWorkers $WORKERS_COUNT/" $APACHE_CONFIG_FILE
```

### Restart Apache server
```shell
systemctl restart apache2.service
```

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.


A high CPU load incident occurs when the CPU usage of a host or server exceeds a certain threshold, typically 80%. This can cause slowdowns, unresponsiveness, or even crashes in the affected system. It is critical to address this issue promptly to minimize impact on users and prevent further damage to the system.


High CPU Load Incident

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 occurs when there is a high number of idle workers in the Apache server. Idle workers are connections that have been established by clients but are not currently processing any requests. When the number of idle workers becomes too high, it can lead to performance issues and potentially impact the server's ability to handle incoming requests. This can lead to slow response times or even server crashes.


High Number of Idle Workers in Apache Server

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

```shell
# Environment Variables

export APACHE_CONFIG_FILE="PLACEHOLDER"

export PATH_TO_APACHE_CONFIG_FILE="PLACEHOLDER"

export DESIRED_NUMBER_OF_WORKERS="PLACEHOLDER"

export MEMORY_LIMIT="PLACEHOLDER"
```


### Check the Apache worker status

```shell
systemctl status apache2
```

### Check the number of Apache workers

```shell
ps aux | grep apache2 | grep -v grep | wc -l
```

### Check the Apache server load

```shell
 apachectl status
```

### Check the Apache server log for errors

```shell
tail -f /var/log/apache2/error.log
```

### Check the server access log for traffic

```shell
tail -f /var/log/apache2/access.log
```

### Check the Apache server configuration file for the maximum worker setting

```shell
grep -i 'MaxRequestWorkers' ${APACHE_CONFIG_FILE}
```

### Check the Apache server configuration file for the current worker setting

```shell
grep -i 'MaxClients' ${APACHE_CONFIG_FILE}
```

### A misconfiguration in the Apache server settings that may cause an imbalance in the load distribution among different workers, leading to an overload on some workers.

```shell


#!/bin/bash

# Check if Apache is installed

if ! command -v apache2 &> /dev/null

then

    echo "Apache is not installed"

    exit

fi

# Check if Apache is running

if ! systemctl is-active --quiet apache2

then

    echo "Apache is not running"

    exit

fi

# Check if Apache configuration is valid

if ! apachectl configtest

then

    echo "Apache configuration is invalid"

    exit

fi

# Check if Apache worker settings are balanced

if [ $(grep -c "BalancerMember" ${PATH_TO_APACHE_CONFIG_FILE}) -lt 2 ]

then

    echo "Apache worker settings are not balanced"

    exit

fi

echo "Apache server is running and workers are balanced"

```


### Define variables

```shell
APACHE_CONFIG_FILE=${PATH_TO_APACHE_CONFIG_FILE}

WORKERS_COUNT=${DESIRED_NUMBER_OF_WORKERS}
```

### Update Apache config file

```shell
sed -i "s/MaxRequestWorkers *[0-9]*/MaxRequestWorkers $WORKERS_COUNT/" $APACHE_CONFIG_FILE
```

### Restart Apache server

```shell
systemctl restart apache2.service
```


High Apache Workers Load

Overview

Parameters

Debug

Check the Apache worker status

Check the number of Apache workers

Check the Apache server load

Check the Apache server log for errors

Check the server access log for traffic

Check the Apache server configuration file for the maximum worker setting

Check the Apache server configuration file for the current worker setting

A misconfiguration in the Apache server settings that may cause an imbalance in the load distribution among different workers, leading to an overload on some workers.

Repair

Define variables

Update Apache config file

Restart Apache server

Learn more

Related Runbooks

High CPU Load Incident

Slowloris Attack Detected on Apache server.

Mod_jk Load Balancing Issues in Apache HTTP.

High Number of Idle Workers in Apache Server

Support