---
id: 268e39af-221c-42b7-8a56-45a6611b2f1b
---

# Apache Server Low Idle Workers
---

This incident type indicates that the number of idle workers in the Apache server is abnormally low, which may result in slower request processing times. The alert is triggered when the average value of the idle workers metric falls below the predicted values.

### Parameters
```shell
# Environment Variables

export APACHE_CONFIG_FILE_PATH="PLACEHOLDER"

export APACHE_STATUS_URL="PLACEHOLDER"

export MAX_IDLE_WORKERS="PLACEHOLDER"

export NEW_IDLE_WORKER_VALUE="PLACEHOLDER"
```

## Debug

### Check the status of the Apache service
```shell
systemctl status apache2
```

### Check the number of idle workers
```shell
apachectl fullstatus | grep "IdleWorkers"
```

### Check the number of active workers
```shell
apachectl fullstatus | grep "BusyWorkers"
```

### Check the Apache error log for any relevant messages
```shell
tail -n 50 /var/log/apache2/error.log
```

### Check the Apache access log for any relevant messages
```shell
tail -n 50 /var/log/apache2/access.log
```

### Check the amount of free memory
```shell
free -m
```

### Check the cpu usage percentage of the system.
```shell
top -bn1 | grep "Cpu(s)" | sed "s/.*, *$[0-9.]*$%* id.*/\1/" | awk '{print 100 - $1}'` 
```

### Check the disk usage of the system
```shell
df -h
```

### Check the network traffic on the server
```shell
iftop
```

### Check the number of connections to the server
```shell
netstat -na | grep :80 | wc -l
```

### Higher than normal traffic on the web server causing a higher number of requests and a lower number of idle workers.
```shell


#!/bin/bash



# Define variables

APACHE_STATUS_URL=${APACHE_STATUS_URL}

MAX_REQUESTS=${MAX_REQUESTS}

MAX_IDLE_WORKERS=${MAX_IDLE_WORKERS}



# Get Apache server status

STATUS=$(curl -s $APACHE_STATUS_URL)



# Extract number of requests and idle workers from the server status

REQUESTS=$(echo "$STATUS" | awk '/^Total Accesses/ {print $3}')

IDLE_WORKERS=$(echo "$STATUS" | awk '/^IdleWorkers/ {print $2}')



# Check if the number of requests exceeds the maximum allowed

if [ "$REQUESTS" -gt "$MAX_REQUESTS" ]; then

    echo "Error: Number of requests ($REQUESTS) exceeds maximum allowed ($MAX_REQUESTS)"

fi



# Check if the number of idle workers is below the minimum required

if [ "$IDLE_WORKERS" -lt "$MAX_IDLE_WORKERS" ]; then

    echo "Error: Number of idle workers ($IDLE_WORKERS) is below the minimum required ($MAX_IDLE_WORKERS)"

fi



# Exit with success status

exit 0


```

## Repair

### Backup the original Apache configuration file
```shell
cp ${APACHE_CONFIG_FILE_PATH} ${APACHE_CONFIG_FILE_PATH}.bak
```

### Replace the existing value of the number of idle workers with the desired value
```shell
sed -i 's/${EXISTING_IDLE_WORKER_VALUE}/${NEW_IDLE_WORKER_VALUE}/g' ${APACHE_CONFIG_FILE_PATH}
```

### Restart Apache service to apply the changes
```shell
systemctl restart apache2
```


This incident type indicates that the number of idle workers in the Apache server is abnormally low, which may result in slower request processing times. The alert is triggered when the average value of the idle workers metric falls below the predicted values.


This incident type is related to the Tomcat server, which is a popular open-source Java application server. It occurs when the available threads in the connection pool are running low, which means that there are not enough resources to serve incoming requests. This can cause delays or even failures in the application's performance, impacting the end-user experience. It is important to monitor and address this issue promptly to ensure that the application runs smoothly and efficiently.


Tomcat Low Available Threads in Connection Pool

This incident type occurs when the number of concurrent connections to a MySQL database server exceeds the configured limit of 80%. This can lead to performance degradation or even database server crashes, making the application or system that relies on the database server unavailable for the end-users. This type of incident typically requires immediate attention and resolution to restore normal operation of the affected service.


MySQL too many connections 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 type refers to a security vulnerability in the SSL/TLS configuration of the Apache HTTP Server, which can leave the server and its users vulnerable to attacks. The SSL/TLS configuration is responsible for encrypting the communication between the server and its clients, and if it is not configured properly, it can be exploited by hackers to intercept or modify sensitive data. This type of incident requires immediate attention from software engineers to ensure that the SSL/TLS configuration is properly configured to prevent any potential security threats.


Inadequate SSL/TLS Configuration for Apache HTTP Server.

```shell
# Environment Variables

export APACHE_CONFIG_FILE_PATH="PLACEHOLDER"

export APACHE_STATUS_URL="PLACEHOLDER"

export MAX_IDLE_WORKERS="PLACEHOLDER"

export NEW_IDLE_WORKER_VALUE="PLACEHOLDER"
```


### Check the status of the Apache service

```shell
systemctl status apache2
```

### Check the number of idle workers

```shell
apachectl fullstatus | grep "IdleWorkers"
```

### Check the number of active workers

```shell
apachectl fullstatus | grep "BusyWorkers"
```

### Check the Apache error log for any relevant messages

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

### Check the Apache access log for any relevant messages

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

### Check the amount of free memory

```shell
free -m
```

### Check the cpu usage percentage of the system.

```shell
top -bn1 | grep "Cpu(s)" | sed "s/.*, *$[0-9.]*$%* id.*/\1/" | awk '{print 100 - $1}'` 
```

### Check the disk usage of the system

```shell
df -h
```

### Check the network traffic on the server

```shell
iftop
```

### Check the number of connections to the server

```shell
netstat -na | grep :80 | wc -l
```

### Higher than normal traffic on the web server causing a higher number of requests and a lower number of idle workers.

```shell


#!/bin/bash



# Define variables

APACHE_STATUS_URL=${APACHE_STATUS_URL}

MAX_REQUESTS=${MAX_REQUESTS}

MAX_IDLE_WORKERS=${MAX_IDLE_WORKERS}



# Get Apache server status

STATUS=$(curl -s $APACHE_STATUS_URL)



# Extract number of requests and idle workers from the server status

REQUESTS=$(echo "$STATUS" | awk '/^Total Accesses/ {print $3}')

IDLE_WORKERS=$(echo "$STATUS" | awk '/^IdleWorkers/ {print $2}')



# Check if the number of requests exceeds the maximum allowed

if [ "$REQUESTS" -gt "$MAX_REQUESTS" ]; then

    echo "Error: Number of requests ($REQUESTS) exceeds maximum allowed ($MAX_REQUESTS)"

fi



# Check if the number of idle workers is below the minimum required

if [ "$IDLE_WORKERS" -lt "$MAX_IDLE_WORKERS" ]; then

    echo "Error: Number of idle workers ($IDLE_WORKERS) is below the minimum required ($MAX_IDLE_WORKERS)"

fi



# Exit with success status

exit 0


```


### Backup the original Apache configuration file

```shell
cp ${APACHE_CONFIG_FILE_PATH} ${APACHE_CONFIG_FILE_PATH}.bak
```

### Replace the existing value of the number of idle workers with the desired value

```shell
sed -i 's/${EXISTING_IDLE_WORKER_VALUE}/${NEW_IDLE_WORKER_VALUE}/g' ${APACHE_CONFIG_FILE_PATH}
```

### Restart Apache service to apply the changes

```shell
systemctl restart apache2
```


Apache Server Low Idle Workers

Overview

Parameters

Debug

Check the status of the Apache service

Check the number of idle workers

Check the number of active workers

Check the Apache error log for any relevant messages

Check the Apache access log for any relevant messages

Check the amount of free memory

Check the cpu usage percentage of the system.

Check the disk usage of the system

Check the network traffic on the server

Check the number of connections to the server

Higher than normal traffic on the web server causing a higher number of requests and a lower number of idle workers.

Repair

Backup the original Apache configuration file

Replace the existing value of the number of idle workers with the desired value

Restart Apache service to apply the changes

Learn more

Related Runbooks

Tomcat Low Available Threads in Connection Pool

MySQL too many connections incident

Slowloris Attack Detected on Apache server.

Mod_jk Load Balancing Issues in Apache HTTP.

Support