After careful consideration, we have made the decision to close new customer access to **AWS Mainframe Modernization self-managed experience**, effective July 30, 2026. Existing customers can continue to use the service as normal. AWS continues to invest in security and availability improvements for AWS Mainframe Modernization self-managed experience, but we do not plan to introduce new features. For more information, see [AWS Mainframe Modernization availability change](https://docs.aws.amazon.com/m2/latest/userguide/mainframe-modernization-availability-change.html). 

**AWS Mainframe Modernization Service (Managed Runtime Environment experience)** is no longer open to new customers. For capabilities similar to AWS Mainframe Modernization Service (Managed Runtime Environment experience) explore AWS Mainframe Modernization Service (Self-Managed Experience). Existing customers can continue to use the service as normal. For more information, see [AWS Mainframe Modernization availability change](https://docs.aws.amazon.com/m2/latest/userguide/mainframe-modernization-availability-change.html). 

# Structure of AWS Transform for mainframe managed applications
<a name="applications-m2-other-resources-structure"></a>

If you use the AWS Transform for mainframe refactoring pattern, the AWS Transform for mainframe runtime engine expects the following structure in the folder specified by `app-location` in your application definition:

![The expected structure within the application-name folder.](http://docs.aws.amazon.com/m2/latest/userguide/images/ba-app-structure.png)


**config**  
Contains the YAML files for your project. These are the YAML files specific to your application, typically named something like `application-planetsdemo.yaml` and not the `application-main.yaml` file that AWS Mainframe Modernization supplies and sets up automatically for you.

**webapps**  
Contains the `war` files for your application. Those files are an output of the modernization process.

An application can also have the following optional folders:

jics/sql  
Contains the `initJics.sql` script that initializes the JICS database for your application.

scripts  
Contains application scripts, which you can also supply directly inside the `war` files.

sql  
Contains application SQL files, which you can also supply directly inside the `war` files.

lnk  
Contains application LNK files, which you can also supply directly inside the `war` files.

extra  
Contains jars that can provide additional capabilities for the modernized application.

## Managing an application's Java options
<a name="java-memory-management"></a>

To manage certain Java options for the application, add a properties file named `tomcat.properties` to the folder specified by `app-location`. This file can have three properties: `xms`, which specifies the minimum Java memory consumption, `xmx`, which specifies the maximum Java memory consumption, and `dnscachettl`, that manages the cache duration for dns resolutions. The following is an example of the contents of a valid `tomcat.properties` file. 

```
xms=512M
xmx=1G
dnscachettl=5
```

The values that you specify for  the first  two properties can be in any of the following units:
+ Bytes: don't specify a unit.
+ Kilobytes: append a K to the value.
+ Megabytes: append an M to the value.
+ Gigabytes: append a G to the value.

The value for the third property represents the cache duration in seconds, and can have value of -1 (cache forever), or can range from 0 (never cache) to 999. In the context of managed application deployments, the default value is -1.