---
id: e810c270-3748-4039-b969-82c4ff23df8b
---

# High Number of Apache Child Processes Incident
---

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.

### Parameters
```shell
export APACHE_PORT="PLACEHOLDER"

export MAX_CONNECTIONS="PLACEHOLDER"
```

## Debug

### Check the resource usage of Apache child processes
```shell
ps aux | grep apache | grep -v grep | awk '{print $2}' | xargs ps u
```

### Check Apache error logs for any issues
```shell
tail -n 100 /var/log/apache/error_log
```

### Check the number of Apache child processes
```shell
ps aux | grep apache | grep -v grep | wc -l
```

### Check Apache access logs for any unusual traffic
```shell
tail -n 100 /var/log/apache/access_log
```

### Check Apache configuration files for any misconfigurations
```shell
apachectl configtest
```

### Check server resource usage (CPU, memory, disk, network) to see if there are any bottlenecks
```shell
top
```

### Check network connections and open ports
```shell
netstat -an | grep ${APACHE_PORT}
```

### Check firewall settings
```shell
iptables -L
```

### Check system log for any relevant messages
```shell
tail -n 100 /var/log/messages
```

## Repair

### Reduce the number of processes by limiting the number of concurrent connections that can be made to Apache.
```shell


#!/bin/bash



# Set the maximum number of concurrent connections allowed

MAX_CONNECTIONS=${MAX_CONNECTIONS}



# Backup the Apache configuration file

cp /etc/httpd/conf/httpd.conf /etc/httpd/conf/httpd.conf.bak



# Edit the Apache configuration file to limit concurrent connections

sed -i "s/MaxClients.*/MaxClients $MAX_CONNECTIONS/" /etc/httpd/conf/httpd.conf



# Restart the Apache service to apply the changes

systemctl restart apache.service


```

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.


In software engineering, a large number of suspended threads in Tomcat is an incident type that occurs when a high number of threads are created but are blocked from executing. This can happen due to a variety of reasons, such as slow database queries, network latency, or resource contention. When this occurs, the system may become unresponsive or slow, causing a degradation in performance or even a complete system failure. It is important to investigate and resolve this issue as quickly as possible to ensure the system can continue to function properly.


Tomcat Large Number of Suspended Threads Incident.

This incident occurs when the Tomcat server is experiencing an unusually high number of active sessions. Active sessions refer to the number of users currently accessing a web application hosted on the Tomcat server. When the number of active sessions exceeds the server's capacity, it can lead to slow response times, unresponsive applications, or even server crashes. This incident requires immediate attention to resolve the issue and prevent any further impact on the web application's performance.


Tomcat High Number of Active Sessions.

This incident type refers to a situation where the Tomcat server's JDBC connection pool usage surpasses its configured limits. This can lead to a shortage of available connections for incoming requests, resulting in slow response times or even server crashes. It is important to monitor and manage the JDBC connection pool usage to prevent such incidents from occurring.


Tomcat High JDBC Connection Pool Usage Incident.

Apache Spark Out of Memory Error is a type of incident that occurs when the Apache Spark application running on a system is unable to allocate enough memory to perform its tasks. This can happen when the system's memory is insufficient or when there is a memory leak in the application's code. When this incident occurs, the application may crash, become unresponsive, or produce incorrect results. It is important to diagnose and resolve this issue as soon as possible to ensure the smooth functioning of the application.


Apache Spark Out of Memory Error incident.

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

```shell
export APACHE_PORT="PLACEHOLDER"

export MAX_CONNECTIONS="PLACEHOLDER"
```


### Check the resource usage of Apache child processes

```shell
ps aux | grep apache | grep -v grep | awk '{print $2}' | xargs ps u
```

### Check Apache error logs for any issues

```shell
tail -n 100 /var/log/apache/error_log
```

### Check the number of Apache child processes

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

### Check Apache access logs for any unusual traffic

```shell
tail -n 100 /var/log/apache/access_log
```

### Check Apache configuration files for any misconfigurations

```shell
apachectl configtest
```

### Check server resource usage (CPU, memory, disk, network) to see if there are any bottlenecks

```shell
top
```

### Check network connections and open ports

```shell
netstat -an | grep ${APACHE_PORT}
```

### Check firewall settings

```shell
iptables -L
```

### Check system log for any relevant messages

```shell
tail -n 100 /var/log/messages
```


### Reduce the number of processes by limiting the number of concurrent connections that can be made to Apache.

```shell


#!/bin/bash



# Set the maximum number of concurrent connections allowed

MAX_CONNECTIONS=${MAX_CONNECTIONS}



# Backup the Apache configuration file

cp /etc/httpd/conf/httpd.conf /etc/httpd/conf/httpd.conf.bak



# Edit the Apache configuration file to limit concurrent connections

sed -i "s/MaxClients.*/MaxClients $MAX_CONNECTIONS/" /etc/httpd/conf/httpd.conf



# Restart the Apache service to apply the changes

systemctl restart apache.service


```


High Number of Apache Child Processes Incident

Overview

Parameters

Debug

Check the resource usage of Apache child processes

Check Apache error logs for any issues

Check the number of Apache child processes

Check Apache access logs for any unusual traffic

Check Apache configuration files for any misconfigurations

Check server resource usage (CPU, memory, disk, network) to see if there are any bottlenecks

Check network connections and open ports

Check firewall settings

Check system log for any relevant messages

Repair

Reduce the number of processes by limiting the number of concurrent connections that can be made to Apache.

Learn more

Related Runbooks

Tomcat Large Number of Suspended Threads Incident.

Tomcat High Number of Active Sessions.

Tomcat High JDBC Connection Pool Usage Incident.

Apache Spark Out of Memory Error incident.

Support