---
id: 92452c4a-8828-446f-9154-9eb2563dd0f7
---

# High Memory Usage by Apache
---

This incident type refers to a situation where the Apache server running on a system is consuming an abnormally high amount of memory. This can result in the system becoming unresponsive or slow, leading to degraded performance. It is important to identify the root cause of the high memory usage and take appropriate measures to optimize the server's performance to avoid such incidents in the future.

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

export MEMORY_USAGE_THRESHOLD_IN_MB="PLACEHOLDER"

export MAX_CLIENTS="PLACEHOLDER"

export KEEP_ALIVE_TIMEOUT="PLACEHOLDER"

export MAX_REQUESTS_PER_CHILD="PLACEHOLDER"
```

## Debug

### Check the memory usage of Apache
```shell
ps -aux | grep apache | awk '{print $4, $11}' | sort -k1 -n
```

### Check the Apache error log
```shell
tail -f /var/log/httpd/error_log
```

### Check the Apache access log
```shell
tail -f /var/log/httpd/access_log
```

### Check the Apache worker status
```shell
apachectl status
```

### Check the Apache configuration
```shell
apachectl configtest
```

### Check the Apache module status
```shell
httpd -M
```

### Check the system memory usage
```shell
free -m
```

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

### Check the server load
```shell
uptime
```

### Check the network connections
```shell
netstat -antp | grep apache
```

## Repair

### Identify the root cause of the high memory usage by Apache by analyzing the server logs and monitoring tools.
```shell
bash

#!/bin/bash



# Set variables

LOGFILE="${PATH_TO_APACHE_LOG_FILE}"

THRESHOLD="${MEMORY_USAGE_THRESHOLD_IN_MB}"



# Check memory usage of Apache process

while true; do

    MEMUSAGE=$(ps -C apache2 -o rss= | awk '{ sum+=$1 } END { print sum/1024 }')

    if (( $(echo "$MEMUSAGE > $THRESHOLD" | bc -l) )); then

        # Log high memory usage

        echo "$(date) - Apache memory usage: $MEMUSAGE MB" >> $LOGFILE

        # Analyze logs and monitoring tools to identify root cause

        # ADD YOUR ANALYSIS STEPS HERE

        break

    fi

    sleep 5

done


```

### Optimize the Apache server configuration by adjusting parameters such as MaxClients, MaxRequestsPerChild, and KeepAliveTimeout to reduce memory usage.
```shell
bash

#!/bin/bash



# Set the variables for MaxClients, MaxRequestsPerChild, and KeepAliveTimeout

MAX_CLIENTS=${MAX_CLIENTS}

MAX_REQUESTS_PER_CHILD=${MAX_REQUESTS_PER_CHILD}

KEEP_ALIVE_TIMEOUT=${KEEP_ALIVE_TIMEOUT}



# Backup the original Apache configuration file before making any changes

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



# Update the MaxClients, MaxRequestsPerChild, and KeepAliveTimeout values in the Apache configuration file

sed -i "s/MaxClients [0-9]\+/MaxClients $MAX_CLIENTS/" /etc/httpd/conf/httpd.conf

sed -i "s/MaxRequestsPerChild [0-9]\+/MaxRequestsPerChild $MAX_REQUESTS_PER_CHILD/" /etc/httpd/conf/httpd.conf

sed -i "s/KeepAliveTimeout [0-9]\+/KeepAliveTimeout $KEEP_ALIVE_TIMEOUT/" /etc/httpd/conf/httpd.conf



# Restart the Apache service to apply the changes

systemctl restart httpd.service



# Check the status of the Apache service to verify if it's running without errors

systemctl status httpd.service


```

This incident type refers to a situation where the Apache server running on a system is consuming an abnormally high amount of memory. This can result in the system becoming unresponsive or slow, leading to degraded performance. It is important to identify the root cause of the high memory usage and take appropriate measures to optimize the server's performance to avoid such incidents in the future.


Tomcat JVM OutOfMemory incident occurs when the Java Virtual Machine (JVM) running the Apache Tomcat server runs out of memory, which causes the server to crash or become unresponsive. This type of incident can happen due to a variety of reasons such as incorrect configuration settings, memory leaks, or insufficient memory allocation. When this incident occurs, it can impact the availability and performance of the web application running on the Tomcat server.


Tomcat JVM OutOfMemory Incident

Tomcat High Swap Usage Incident refers to an event where Tomcat, a popular open-source web server, is experiencing high swap usage. Swap usage is a memory management technique used by the operating system to temporarily move data from RAM to the hard disk. When Tomcat is consuming high swap memory, it can cause the server to slow down or even crash, resulting in downtime for the website or application hosted on the server. This incident type requires immediate attention to identify the root cause and resolve the issue to prevent further downtime.


Tomcat High Swap Usage 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.

This incident type refers to the situation where the Tomcat server is utilizing more memory than it should, causing system instability and performance issues. This can happen due to a variety of factors such as memory leaks, improper configuration, or application code issues. It is important to address this incident promptly to prevent system failures and ensure optimal application performance.


Excessive memory usage by Tomcat.

```shell
export PATH_TO_APACHE_LOG_FILE="PLACEHOLDER"

export MEMORY_USAGE_THRESHOLD_IN_MB="PLACEHOLDER"

export MAX_CLIENTS="PLACEHOLDER"

export KEEP_ALIVE_TIMEOUT="PLACEHOLDER"

export MAX_REQUESTS_PER_CHILD="PLACEHOLDER"
```


### Check the memory usage of Apache

```shell
ps -aux | grep apache | awk '{print $4, $11}' | sort -k1 -n
```

### Check the Apache error log

```shell
tail -f /var/log/httpd/error_log
```

### Check the Apache access log

```shell
tail -f /var/log/httpd/access_log
```

### Check the Apache worker status

```shell
apachectl status
```

### Check the Apache configuration

```shell
apachectl configtest
```

### Check the Apache module status

```shell
httpd -M
```

### Check the system memory usage

```shell
free -m
```

### Check the disk usage

```shell
df -h
```

### Check the server load

```shell
uptime
```

### Check the network connections

```shell
netstat -antp | grep apache
```


### Identify the root cause of the high memory usage by Apache by analyzing the server logs and monitoring tools.

```shell
bash

#!/bin/bash



# Set variables

LOGFILE="${PATH_TO_APACHE_LOG_FILE}"

THRESHOLD="${MEMORY_USAGE_THRESHOLD_IN_MB}"



# Check memory usage of Apache process

while true; do

    MEMUSAGE=$(ps -C apache2 -o rss= | awk '{ sum+=$1 } END { print sum/1024 }')

    if (( $(echo "$MEMUSAGE > $THRESHOLD" | bc -l) )); then

        # Log high memory usage

        echo "$(date) - Apache memory usage: $MEMUSAGE MB" >> $LOGFILE

        # Analyze logs and monitoring tools to identify root cause

        # ADD YOUR ANALYSIS STEPS HERE

        break

    fi

    sleep 5

done


```

### Optimize the Apache server configuration by adjusting parameters such as MaxClients, MaxRequestsPerChild, and KeepAliveTimeout to reduce memory usage.

```shell
bash

#!/bin/bash



# Set the variables for MaxClients, MaxRequestsPerChild, and KeepAliveTimeout

MAX_CLIENTS=${MAX_CLIENTS}

MAX_REQUESTS_PER_CHILD=${MAX_REQUESTS_PER_CHILD}

KEEP_ALIVE_TIMEOUT=${KEEP_ALIVE_TIMEOUT}



# Backup the original Apache configuration file before making any changes

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



# Update the MaxClients, MaxRequestsPerChild, and KeepAliveTimeout values in the Apache configuration file

sed -i "s/MaxClients [0-9]\+/MaxClients $MAX_CLIENTS/" /etc/httpd/conf/httpd.conf

sed -i "s/MaxRequestsPerChild [0-9]\+/MaxRequestsPerChild $MAX_REQUESTS_PER_CHILD/" /etc/httpd/conf/httpd.conf

sed -i "s/KeepAliveTimeout [0-9]\+/KeepAliveTimeout $KEEP_ALIVE_TIMEOUT/" /etc/httpd/conf/httpd.conf



# Restart the Apache service to apply the changes

systemctl restart httpd.service



# Check the status of the Apache service to verify if it's running without errors

systemctl status httpd.service


```


High Memory Usage by Apache

Overview

Parameters

Debug

Check the memory usage of Apache

Check the Apache error log

Check the Apache access log

Check the Apache worker status

Check the Apache configuration

Check the Apache module status

Check the system memory usage

Check the disk usage

Check the server load

Check the network connections

Repair

Identify the root cause of the high memory usage by Apache by analyzing the server logs and monitoring tools.

Optimize the Apache server configuration by adjusting parameters such as MaxClients, MaxRequestsPerChild, and KeepAliveTimeout to reduce memory usage.

Learn more

Related Runbooks

Tomcat JVM OutOfMemory Incident

Tomcat High Swap Usage Incident

Tomcat High Number of Active Sessions.

Tomcat High JDBC Connection Pool Usage Incident.

Support