---
id: b45afebe-abc3-42d4-b2d3-b0e21f48d1ec
---

# Tomcat JVM OutOfMemory Incident
---

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.

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

export TOMCAT_PID="PLACEHOLDER"

export HEAP_DUMP_FILE_PATH="PLACEHOLDER"

export THRESHOLD="PLACEHOLDER"
```

## Debug

### Check if there's enough available memory
```shell
free -m
```

### Check the current memory usage by the Tomcat server
```shell
ps -ef | grep tomcat
```

### Check the memory settings in the Tomcat configuration file
```shell
cat ${PATH_TO_TOMCAT}/bin/setenv.sh
```

### Check the JVM memory usage
```shell
jstat -gc ${TOMCAT_PID} 1000 10
```

### Check the heap dump for memory leaks
```shell
jmap -dump:format=b,file=${HEAP_DUMP_FILE_PATH} ${TOMCAT_PID}
```

### Analyze the heap dump for memory leak issues
```shell
jhat ${HEAP_DUMP_FILE_PATH}
```

### Check the garbage collector logs for clues
```shell
tail -f ${PATH_TO_TOMCAT}/logs/gc.log
```

### Check for any errors in the Tomcat logs
```shell
tail -f ${PATH_TO_TOMCAT}/logs/catalina.out
```

### Memory Leak: One of the possible reasons for the Tomcat JVM OutOfMemory incident could be a memory leak in the application causing it to consume all available memory.
```shell


#!/bin/bash



# Step 1: Get the process ID of the Tomcat application

pid=$(ps -ef | grep "tomcat" | grep -v grep | awk '{print $2}')



# Step 2: Get the current memory usage of the Tomcat application

mem=$(cat /proc/$pid/status | grep VmRSS | awk '{print $2}')



# Step 3: Check if the memory usage has increased since the last check

if [ "$mem" -gt "${THRESHOLD}" ]; then

    echo "Memory Leak Detected: Memory usage has exceeded the threshold of ${THRESHOLD} KB"

    echo "Memory usage: $mem KB"

    # Step 4: Generate a heap dump for analysis

    jmap -dump:format=b,file=/tmp/heapdump.hprof $pid

else

    echo "Memory usage is within normal limits"

fi


```

## Repair

### Increase the memory allocation for the Tomcat server by modifying its configuration files.
```shell


#!/bin/bash

# Define variables for memory allocation values

export ${MEMORY_XMS}=${VALUE}

export ${MEMORY_XMX}=${VALUE}

# Define variable for Tomcat configuration file path

export ${TOMCAT_CONF}=${PATH}

# Edit the Tomcat configuration file to increase memory allocation

sed -i "s/-Xmx[0-9]*m/-Xmx${MEMORY_XMX}m/g" $TOMCAT_CONF

sed -i "s/-Xms[0-9]*m/-Xms${MEMORY_XMS}m/g" $TOMCAT_CONF


# Restart the Tomcat server to apply the changes

systemctl restart tomcat.service


```

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.


The Host Out of Memory (OOM) Incident occurs when a server or system runs out of memory, causing it to crash or become unresponsive. This can be caused by various factors, such as an unexpected surge in traffic or insufficient resources allocated to the system. Resolving this type of incident requires identifying the root cause of the memory issue and taking appropriate measures such as optimizing system resources or increasing memory capacity.


Host Out of Memory (OOM) Incident

When too many requests are sent to a Tomcat server, the thread pools that handle these requests can run out of available threads. This means that incoming requests will not be processed, leading to service degradation or even a complete outage. This incident type is critical for web applications that rely on Tomcat as their application server.


Tomcat thread pool exhaustion.

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

This incident type occurs when the PermGen or Metaspace usage of the Tomcat server exceeds 90%. PermGen and Metaspace are memory pools used for storing class definitions and metadata of the Java virtual machine (JVM). When these memory pools reach their maximum capacity, the server may experience performance issues or even crash. This incident requires immediate attention from the software engineer to investigate the root cause and take appropriate actions to resolve the issue.


Tomcat PermGen or Metaspace Usage exceeds 90%

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

```shell
export PATH_TO_TOMCAT="PLACEHOLDER"

export TOMCAT_PID="PLACEHOLDER"

export HEAP_DUMP_FILE_PATH="PLACEHOLDER"

export THRESHOLD="PLACEHOLDER"
```


### Check if there's enough available memory

```shell
free -m
```

### Check the current memory usage by the Tomcat server

```shell
ps -ef | grep tomcat
```

### Check the memory settings in the Tomcat configuration file

```shell
cat ${PATH_TO_TOMCAT}/bin/setenv.sh
```

### Check the JVM memory usage

```shell
jstat -gc ${TOMCAT_PID} 1000 10
```

### Check the heap dump for memory leaks

```shell
jmap -dump:format=b,file=${HEAP_DUMP_FILE_PATH} ${TOMCAT_PID}
```

### Analyze the heap dump for memory leak issues

```shell
jhat ${HEAP_DUMP_FILE_PATH}
```

### Check the garbage collector logs for clues

```shell
tail -f ${PATH_TO_TOMCAT}/logs/gc.log
```

### Check for any errors in the Tomcat logs

```shell
tail -f ${PATH_TO_TOMCAT}/logs/catalina.out
```

### Memory Leak: One of the possible reasons for the Tomcat JVM OutOfMemory incident could be a memory leak in the application causing it to consume all available memory.

```shell


#!/bin/bash



# Step 1: Get the process ID of the Tomcat application

pid=$(ps -ef | grep "tomcat" | grep -v grep | awk '{print $2}')



# Step 2: Get the current memory usage of the Tomcat application

mem=$(cat /proc/$pid/status | grep VmRSS | awk '{print $2}')



# Step 3: Check if the memory usage has increased since the last check

if [ "$mem" -gt "${THRESHOLD}" ]; then

    echo "Memory Leak Detected: Memory usage has exceeded the threshold of ${THRESHOLD} KB"

    echo "Memory usage: $mem KB"

    # Step 4: Generate a heap dump for analysis

    jmap -dump:format=b,file=/tmp/heapdump.hprof $pid

else

    echo "Memory usage is within normal limits"

fi


```


### Increase the memory allocation for the Tomcat server by modifying its configuration files.

```shell


#!/bin/bash

# Define variables for memory allocation values

export ${MEMORY_XMS}=${VALUE}

export ${MEMORY_XMX}=${VALUE}

# Define variable for Tomcat configuration file path

export ${TOMCAT_CONF}=${PATH}

# Edit the Tomcat configuration file to increase memory allocation

sed -i "s/-Xmx[0-9]*m/-Xmx${MEMORY_XMX}m/g" $TOMCAT_CONF

sed -i "s/-Xms[0-9]*m/-Xms${MEMORY_XMS}m/g" $TOMCAT_CONF


# Restart the Tomcat server to apply the changes

systemctl restart tomcat.service


```


Tomcat JVM OutOfMemory Incident

Overview

Parameters

Debug

Check if there's enough available memory

Check the current memory usage by the Tomcat server

Check the memory settings in the Tomcat configuration file

Check the JVM memory usage

Check the heap dump for memory leaks

Analyze the heap dump for memory leak issues

Check the garbage collector logs for clues

Check for any errors in the Tomcat logs

Memory Leak: One of the possible reasons for the Tomcat JVM OutOfMemory incident could be a memory leak in the application causing it to consume all available memory.

Repair

Increase the memory allocation for the Tomcat server by modifying its configuration files.

Learn more

Related Runbooks

Host Out of Memory (OOM) Incident

Tomcat thread pool exhaustion.

Tomcat Server Crash

Tomcat PermGen or Metaspace Usage exceeds 90%

Support