In Linux, there are limits characterized by the framework for whatever burns-through assets. For instance, there are limits on the number of contentions can be passed to a specific order, the number of strings can run simultaneously, and so forth.
In this post, We will configure or increase the open file limit for apache tomcat 8 on ubuntu 20.04 LTS
Step 1:- Get Maximum System Capability
First sysAdmin need to check maximum capability of system, Use the following command for the same.
cat /proc/sys/fs/file-maxYou should get output like this.
708444
Step 2:- Get Available Limit
Now need to verify available limit by using following commands, Use the following command for the same.
ulimit -nYou should get output like tihs.
1024
Step 3 :- Increase the Available Limit
To increase the available limit to say 200000 use the following commands.
sudo vim /etc/sysctl.conf
add the following line to it
fs.file-max = 200000
Step 4 :-Refresh the New Config
Need to run this to refresh with new config, Use the following command for the same.
sudo sysctl -p
Step 5 :- Configure the limits.conf file
Now need to edit the following file, Use the following command.
sudo vim /etc/security/limits.conf
add following lines to it
# End of file
* soft nofile 120000
* hard nofile 120000
* soft nproc 120000
* hard nproc 120000
Save and exit
Step 6 :- Configure the pam.d/common-session config file
Now need to edit the following file sudo vim /etc/pam.d/common-session
sudo vim /etc/pam.d/common-session
# add this line to it
session required pam_limits.soStep 7 :- Logout and Login
Now need to logout and login and try the following command to get effects.
ulimit -n
You should get value like this 200000
After configure ulimit in system, We need to configure tomcat for open files limit by following the steps,
Step 8:- Get PID of Tomcat
Need to check PID of tomcat by following the commands
sudo systemctl status tomcat.service
Now you should see like this output grep the tomcat service main process ID
Loaded: loaded (/etc/systemd/system/tomcat.service; disabled; vendor preset: enabled)
Active: active (running) since Mon 2019-02-25 14:59:53 IST; 31min ago
Process: 26977 ExecStop=/opt/tomcat/bin/shutdown.sh (code=exited, status=0/SUCCESS)
Process: 27041 ExecStart=/opt/tomcat/bin/startup.sh (code=exited, status=0/SUCCESS)
Main PID: 27049 (java)
CGroup: /system.slice/tomcat.service
└─27049 /usr/lib/jvm/java-1.8.0-openjdk-amd64/jre/bin/java -Djava.util.logging.config.file=/opt/tomca
Feb 25 14:59:53
Step 9:- Get Open File Limit
Now you need to see open files limits by tomcat process id like this :–
cat /proc/<processId>/limits
Limit Soft Limit Hard Limit Units
Max cpu time unlimited unlimited seconds
Max file size unlimited unlimited bytes
Max data size unlimited unlimited bytes
Max stack size 8388608 unlimited bytes
Max core file size 0 unlimited bytes
Max resident set unlimited unlimited bytes
Max processes 47597 47597 processes
Max open files 8192 8192 files
Max locked memory 65536 65536 bytes
Max address space unlimited unlimited bytes
Max file locks unlimited unlimited locks
Max pending signals 47597 47597 signals
Max msgqueue size 819200 819200 bytes
Max nice priority 0 0
Max realtime priority 0 0
Max realtime timeout unlimited unlimited us Step 10:- Increase the Tomcat’s Open file limit
Now if you want to change open files limit of tomcat web server you need to edit the tomcat’s service file located in vim /etc/systemd/system/tomcat.service
sudo vim /etc/systemd/system/tomcat.service
Open and add lines after [Services] like this
[Service]
LimitNOFILE=8192
The completed example is given below:--
[Unit]
Description=Apache Tomcat Web Application Container
After=network.target
[Service]
LimitNOFILE=10192
Type=forking
Environment=JAVA_HOME=/usr/lib/jvm/java-1.8.0-openjdk-amd64/jre
Environment=CATALINA_PID=/opt/tomcat/temp/tomcat.pid
Environment=CATALINA_HOME=/opt/tomcat
Environment=CATALINA_BASE=/opt/tomcat
Environment='CATALINA_OPTS=-Xms512M -Xmx1024M -server -XX:+UseParallelGC'
Environment='JAVA_OPTS=-Djava.awt.headless=true -Djava.security.egd=file:/dev/./urandom'
ExecStart=/opt/tomcat/bin/startup.sh
ExecStop=/opt/tomcat/bin/shutdown.sh
User=tomcat
Group=tomcat
UMask=0007
RestartSec=10
Restart=always
[Install]
WantedBy=multi-user.targetSave and Exit
Step 12:- Restart the Tomcat Service
To get effects on tomcat services you need to restart the tomcat service but before that you must have to reload the daemons by using the given commands:–
sudo systemctl daemon-reload
sudo systemctl restart tomcat.service
sudo systemctl status tomcat.service
To get again status of tomcat open files limit use the given commands with new tomcat PID
cat /proc/8005/limitsNow you should get output like that :–
Limit Soft Limit Hard Limit Units
Max cpu time unlimited unlimited seconds
Max file size unlimited unlimited bytes
Max data size unlimited unlimited bytes
Max stack size 8388608 unlimited bytes
Max core file size 0 unlimited bytes
Max resident set unlimited unlimited bytes
Max processes 47597 47597 processes
Max open files 100000 100000 files
Max locked memory 65536 65536 bytes
Max address space unlimited unlimited bytes
Max file locks unlimited unlimited locks
Max pending signals 47597 47597 signals
Max msgqueue size 819200 819200 bytes
Max nice priority 0 0
Max realtime priority 0 0
Max realtime timeout unlimited unlimited us
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