Enable Remote Access to Tomcat Manager

 

Step 1: Install Apache Tomcat

Before we start, make sure you have Apache Tomcat installed on your server or computer. If you haven’t installed it yet, you can download it from the official Tomcat website and follow the installation instructions.

Step 2: Locate the Tomcat Configuration File

1. Open the folder where Tomcat is installed.
2. Find the conf directory.
3. In this directory, locate the tomcat-users.xml file. This file is used to manage users and roles.

Step 3: Edit the tomcat-users.xml File

1. Open the tomcat-users.xml file with a text editor.
2. Add the following lines inside the <tomcat-users> tags to create a user with the manager role:

   
   <role rolename="manager-gui"/>
   <user username="admin" password="admin_password" roles="manager-gui"/>
   
   

Replace admin with your desired username and admin_password with a strong password.

ADVERTISEMENT
3. Save the changes and close the file.

Step 4: Allow Remote Access To Manager App

1. Go to the webapps/manager/META-INF/ directory.
2. Open the context.xml file located in that directory with a text editor.
3. Find the section that looks like this:

   
   <Valve className="org.apache.catalina.valves.RemoteAddrValve"
       allow="127\.\d+\.\d+\.\d+|::1|0:0:0:0:0:0:0:1" />
   
   
4. Change the allow attribute to include your IP address or a range of IP addresses from which you want to allow access. For example:

   
   <Valve className="org.apache.catalina.valves.RemoteAddrValve"
       allow="127\.\d+\.\d+\.\d+|::1|0:0:0:0:0:0:0:1|192\.168\.1\.\d+" />
   
   

   This example allows access from any IP address in the 192.168.1.x range.

5. Save the changes and close the file.

Step 5: Allow Remote Access To Host Manager

1. Go to the webapps/host-manager/META-INF/ directory.
2. Open the context.xml file located in webapps/host-manager/META-INF/ directory with a text editor.
3. Find the section that looks like this:

   
   <Valve className="org.apache.catalina.valves.RemoteAddrValve"
       allow="127\.\d+\.\d+\.\d+|::1|0:0:0:0:0:0:0:1" />
   
   
4. Change the allow attribute to include your IP address or a range of IP addresses from which you want to allow access. For example:

   
   <Valve className="org.apache.catalina.valves.RemoteAddrValve"
       allow="127\.\d+\.\d+\.\d+|::1|0:0:0:0:0:0:0:1|192\.168\.1\.\d+" />
   
   

   This example allows access from any IP address in the 192.168.1.x range.

   ADVERTISEMENT

5. Save the changes and close the file.

Step 6: Restart Tomcat

For the changes to take effect, you need to restart Tomcat. You can do this by running the shutdown script followed by the startup script located in the bin directory of your Tomcat installation:

• For Windows:

  
  shutdown.bat
  startup.bat
  
  
• For Linux:
  Linux server distribution

  
  ./shutdown.sh
  ./startup.sh
  
  

Step 7: Access Tomcat Manager Remotely

Open a web browser and go to http://<your-server-ip>:8080/manager. You should see the Tomcat Manager login page. Enter the username and password you created in the tomcat-users.xml file.

======================

file edit

setenv.sh

export CATALINA_OPTS="$CATALINA_OPTS -Xms28672m"

export CATALINA_OPTS="$CATALINA_OPTS -Xmx28672m"

======================

hikari-config.propraties

 [root@Agent-Application-1 sharif]# cat  /u01/tomcat-finger-others/apache-tomcat-9.0.86/apache-tomcat-9.0.86/webapps/FingerAPI/WEB-INF/classes/hikari-config.properties

driverName = oracle.jdbc.OracleDriver

url = jdbc:oracle:thin:@10.x.x.x:1521/emob

user = xxxxxx

pass = xxxxxx

#Newly Added

cachePrepStmts = true

prepStmtCacheSize = 2500

prepStmtCacheSqlLimit = 2048

minimumIdle = 20

maximumPoolSize = 10

idleTimeout = 600000

connectionTimeout = 3000000

maxLifetime = 1000000

VT-X enable for processor in Ubuntu

 

How to enable nested virtualization

For Windows host enable VT-X for processor on Ubuntu linux are as below:

  Set-VMProcessor -VMname BOTOP -ExposeVirtualizationExtensions $true

  Set-VMProcessor -VMname BOT-IVRCRM -ExposeVirtualizationExtensions $true

 ------------------------

Check if nested virtualization is enabled

Check if the required kernel module for your CPU is already loaded. Hosts with Intel CPUs require the kvm_intel module while AMD hosts require kvm_amd instead:

$ lsmod | grep -i kvm
kvm_intel               204800  0
kvm                  1347584  1 kvm_intel

If the module is loaded

If the module is already loaded, you can check if nested virtualization is enabled by running the following command:

cat /sys/module/<module>/parameters/nested

As an example for AMD hosts:

$ cat /sys/module/kvm_amd/parameters/nested
1

If the output is either 1 or Y then nested virtualization is enabled and you will not need to manually enable the feature (this should be the case for Ubuntu users).

If the module is not loaded

If the module your host requires is not loaded you can load it using modprobe and add the property nested=1 to enable nested virtualization as shown below for Intel hosts:

modprobe kvm-intel nested=1

Or as follows for AMD hosts:

modprobe kvm-amd nested=1

Enable nested virtualization

If the above checks indicate that nested virtualization is not enabled, you can follow the below steps to enable it.

• Create a file in /etc/modprobe.d -e.g., /etc/modprobe.d/kvm.conf- and add the line options kvm-intel nested=1 to that file (replace kvm-intel with kvm-amd for AMD hosts).

• Reload the kernel module to apply the changes:

  sudo modprobe -r <module>

Example for Intel hosts:

  sudo modprobe -r kvm-intel

• You should now be able to see nested virtualization enabled:

Example for Intel hosts:

  $ cat /sys/module/kvm_intel/parameters/nested
  Y

Check and enable nested virtualization inside an instance

Once the host is ready to use nested virtualization it is time to check if the guest instance where the other instance(s) are going to run is able to host these nested VMs.

To determine if an instance can host another instance on top, run the below command within the instance:

egrep "svm|vmx" /proc/cpuinfo