Application Mode configuration

Application Mode starts applications when the Deephaven server starts. Each application loaded from a file has one *.app file that defines it. Some applications are discovered another way, such as through a ServiceLoader factory, and need no .app file.

The deephaven.application.dir property sets the application directory. When that property is unset, the server uses the app.d directory inside the Deephaven configuration directory, if it exists.

Each *.app file can have any name that ends in .app. The file must be a regular file. It must not be a symbolic link, and it must be in the application directory.

The server loads .app files in lexicographic order by file name. It skips any file that is not a readable .app regular file, without reporting an error. A readable .app file with an invalid definition, such as one with no type, stops the server from starting.

The following file defines a script application that runs helloWorld.groovy on a Groovy server. The Common properties and Script applications sections describe each property.

type=script
scriptType=groovy
enabled=true
id=hello.world
name=Hello World!
file_0=helloWorld.groovy

Common properties

Parameter Type Description

type

String

Parameter	Type	Description
type	String	Required. The kind of application. Valid values: `script` runs the scripts listed in `file_<n>`. `static` creates the application from the class named in `class`. See Class-based applications. `dynamic` creates the application from the class named in `class`. See Class-based applications. `qst` is reserved and not implemented, so an application of this type never runs.
enabled	Boolean	Optional. Whether the server loads this application. `true` (default) loads the application. The value is not case-sensitive. Any other value, such as `false` or `yes`, skips the application. The server still reads and validates a skipped application's definition, so a disabled file with an invalid definition still stops the server from starting.

Required. The kind of application. Valid values:

script runs the scripts listed in file_<n>.
static creates the application from the class named in class. See Class-based applications.
dynamic creates the application from the class named in class. See Class-based applications.
qst is reserved and not implemented, so an application of this type never runs.

enabled

Boolean

Optional. Whether the server loads this application.

true (default) loads the application. The value is not case-sensitive.
Any other value, such as false or yes, skips the application. The server still reads and validates a skipped application's definition, so a disabled file with an invalid definition still stops the server from starting.

Script applications

These properties apply when type is script.

Parameter	Type	Description
scriptType	String	Required. The language of the script, `python` or `groovy`. For an enabled application, it must match the language of the server (set with `-Ddeephaven.console.type`), or the server fails to start. The value is not case-sensitive.
id	String	Required. A unique identifier for the application. API clients use it to look up the application's fields. A field is a named value that the application publishes for clients to fetch by name. No two enabled applications on a server can share an `id`. The `id` `scope` is reserved, so an application with that `id` cannot publish fields.
name	String	Required. The application's display name.
file_<n>	String	Required. The path to one script to run, where `<n>` is a string of ASCII digits, such as `file_0` and `file_1`. Keys whose suffix contains other characters, such as `file_+1` or `file_a`, are ignored. A number above 2147483647 stops the server from starting. Specify at least one. Relative paths resolve against the application directory. Scripts run in ascending order of `<n>`, not in the order they appear in the file. The server ignores keys whose suffix is not an integer, such as `file_a`.

Class-based applications

This property applies when type is static or dynamic.

Parameter Type Description

class

String

Parameter	Type	Description
class	String	Required. The fully qualified name of a class that has a no-argument constructor. The class implements one of these interfaces: For `static` applications, `io.deephaven.appmode.Application.Factory`. The application declares all of its exported variables when the server starts. For `dynamic` applications, `io.deephaven.appmode.ApplicationState.Factory`. The application can add or remove exported variables as its state changes.

Required. The fully qualified name of a class that has a no-argument constructor. The class implements one of these interfaces:

For static applications, io.deephaven.appmode.Application.Factory. The application declares all of its exported variables when the server starts.
For dynamic applications, io.deephaven.appmode.ApplicationState.Factory. The application can add or remove exported variables as its state changes.

Application Mode configuration

Common properties

Script applications

Class-based applications

Related documentation