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.