Discover Tomcat

Understanding Tomcat Applications

A J2EE web application running on a Tomcat server may have its dependencies on various resources configured on the container, such as data sources, JMS modules, shared application libraries, server configurations, etc. These configurations are defined in Tomcat server in its server.xml or context.xml.

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Discover Tomcat Applications

When the host machine is running a Tomcat server, the Discover Host feature not only collects all the information from the host machine such as system information, process information, memory information, etc., but also scans the Tomcat server configuration for all the applications that can be containerized into separate independent containers.

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Information About Tomcat Applications

Once the discovery of the host running a Tomcat server is done, CHAI™ UI lists each application that is ready for individual containerization. These applications include the applications deployed on all the clusters or on the standalone servers. The following information is revealed by the CHAI™ UI for each application:

• The Tomcat application information
• The shared libraries on which the Tomcat application depends
• The resource configurations on the server on which the application is running. In the case of an application deployed on a cluster, the configuration info of any one server is taken as a template, as the assumption is that the servers in the cluster will probably have the same configuration
• The application configurations like data sources and JMS modules that are deployed on the server/cluster

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Tomcat Application Server Objects Supported for Transform

Objects	Discover	Transform
Shared Application Libraries	Yes	Yes
Server Certificates	Yes	Yes
JNDI Data Sources	Yes	Yes
JNDI User Database	Yes	Yes
JNDI JavaMail Sessions	Yes	Yes
JMS Configuration	Yes	Yes
Cluster	Yes	No
Virtual Host	Yes	Yes
Logging	Yes	Yes
JDBC Realms	Yes	Yes
DataSource Realms	Yes	Yes
JNDI Realms	Yes	Yes (Active Directory)
UserDatabase Realms	Yes	Yes
Memory Realms	Yes	Yes
Valve	Yes	Yes
JNDI Java Beans	No	No
JNDI Custom	No	No
Security Manager	No	No
CGI	No	No
JAAS Realm	No	No
Lifecycle Listeners	No	No
Request Filters	No	No
Memory and Garbage Collection Settings	No	No

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Process Flow for Discovery of Tomcat Applications

1. Add Tomcat server host for discovery
2. Prerequisites check on discovery host
3. Phase 1 discovery
4. Transform a Tomcat application into a container

To find out about Linux host prerequisites, please click here.

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Tomcat Applications Discovery

Step 1: Add Project

In the landing page, click Add Project. Add respective details and click Save. This will take you to the discover page.

Step 2: Check Connection

Click on the 3 horizontal dots beside the host and click Check Connection and wait for a few seconds.

Note: - You will get a success message in a few seconds - This step is optional. This step is just to make sure that the connection is established successfully

Step 3: Check Prerequisites

Click the Check prerequisites button as shown in the image below and wait for a few seconds.

You can see the prerequisites logs from the Logs section at the bottom when the prerequisite check is started as shown in the image below.

Logs are divided into 2 parts:

1. Network Connectivity Checks: Shows the network connectivity checks on the host machine
2. Validating Prerequisites: Shows the checks if all the prerequisites are available or not

Step 4: Edit the Ignore List (Optional)

You can edit the ignore list before starting a discovery by clicking on the Process Ignore List button as shown in the image below. The ignore list is used to skip the discovery process from analyzing these processes on the host. Do not ignore the Java processes. Using this feature, you can include or exclude the processes for discovery as shown in the image below.

Notes: - You can also edit the ignore list after a discovery is done - Any modification done in the ignore list after discovery will require the discovery for the host to be performed again

Step 5: Edit the Application Ignore List (Optional)

You can edit the application ignore list before starting a discovery by clicking on the Application Ignore List tab as shown in the image below.

The application ignore list is used to identify the applications that you want to containerize.

Using this feature, you can specify the application names only which are to be included for discovery, as shown in the image below. All the other applications will not be scanned by the discovery process.

Step 6: Discover

Click the Discover button and wait for a few seconds.

• You will get the message "Triggering Discovery"
• After a few minutes, you will see the discovery status as Completed if all the prerequisites are met
• You can see the discover logs from the Logs section at the bottom when the discover process is started as shown in the image below

Logs are divided into 3 parts (including the prerequisites):

1. Network Connectivity Checks: Shows the network connectivity checks on the host machine
2. Validating Prerequisites: Shows the checks if all the prerequisites are available or not
3. Collecting System State Information: Shows the logs for collecting all the system information

Once the discovery is completed, you will be able to see all the processes discovered, including the Tomcat processes (java), and the web applications that are discovered, as shown in the image below.

The web applications that are discovered from the Tomcat server are listed in the table with the process name formatted as java-<vhost>-<Cluster/Server name>-<applicationName>. For example, if an application say 'appX' is deployed on one standalone server say Server-1, and a cluster Cluster-0, then the table will show two entries for the application with names as java-Server-1-appX and java-Cluster-0-appX. This helps you to choose the application to transform with the specific server settings or the cluster settings.

Step 7: View Web Application Information

You can view the web application information specific to Tomcat application by clicking on the name of the application (More Info) under the Name column. The information screen with tabs will be shown as below:

Process Details Tab

This tab shows the details of the process which enabled discovering the applications. This will usually be the Tomcat server process as the discovery is run on the deployment manager.

Web Application Details Tab

This tab shows the details of the web application as shown below:

• Application Name: Shows the name of the application. This is the same as that shown in the process table that is clicked. The formation of the application name includes the name followed by #<specification version>@<app/library version>
• Server Name: Shows the name of the target server for this application
• Java Version: Shows the version of Java used by the Tomcat server process. Assuming the same version is being used across all the servers in the Tomcat cluster deployment if any
• Context Root: Shows the context root of the web application if specifically defined in application.xml of the war/ear
• Location: Shows the location of the application archive (war/ear). This application archive is copied over to the container for deployment
• Dependent Shared Libraries: Shows the list of shared application libraries detected on the cluster/server on which the application is also targeted. The assumption is that the application may refer to any of these dependencies as they are all existing on the same target

Application Server Tab

This tab shows the details about the target server or cluster-specific configuration information. The assumption is that the Java version will be the same across all servers in the cluster deployment. Also, the servers in the cluster will all have the same configurations.

• Name: Shows the name of the application server; in this case it is "Apache Tomcat"
• Server Version: Shows the Tomcat server version of the process detected on the discovered system
• HOME DIR: Shows the Tomcat server (process's) home directory
• Application Default Ports: Shows the ports (SSL and non-SSL) being used by the target server for this application
• Clusters & Servers List: Shows the list of all the servers and clusters that this application is targeted on

Application Configuration Details Tab

• Certificate Details: Shows the Tomcat server's SSL configuration. It displays the identity key store file and the trust store details configured on the Tomcat server
• Data Sources: Shows the list of data sources configured on the server on which this application is targeted. All these data source configurations are carried over to the container during transformation of this application
• JMS Modules: Shows the list of JMS modules targeted on the server on which this application is also targeted. These JMS module configurations are carried over to the container with the assumption that the JMS server will remain running as is and the container will be able to use the existing JMS server for its queues/topics. The container will be configured with foreign server connection factory, configured to connect to this existing JMS server

Step 8: Next Step - Transformation

The next step will be transformation of the Tomcat application. Please click here.

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Force Discover

You can also force discover the host if the discovery process is taking a long time and you want to re-initiate the discovery.

To force discover the host, you will have to click the Force Discover button.