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Find dead data

Recipe IDio.moderne.mainframe.lineage.FindDeadData

Artifactio.moderne.recipe:recipes-mainframe

Find declared fields that nothing reads, and fields written but never read back. Carrying data nobody uses is the cheapest thing to drop from a migration, and unused fields accumulate over decades because nothing makes them visible. Reading is counted through the record structure — a field read as part of a group move counts — and includes being tested in a condition, which moves no value. FILE and LINKAGE items are excluded, since something outside the program supplies and consumes them.

Single recipeOpenRewriteModerne Proprietary License

Try in PlatformTry this recipe in the Moderne platform. Not a user yet? You’ll get a no-setup demo environment, with nothing to install or configure.

Options

1 parameters

1 optional

Parameter	Example	Type	Required
includeCopybookFields	—	Boolean	Optional
Whether to report fields copied in from a copybook. They are off by default because a field unused here is often used by another program copying the same book, and only a portfolio-wide answer can tell them apart. Defaults to false.

Usage

Run this recipe

This recipe has no required configuration options. Users of Moderne can run it via the Moderne CLI.

You will need to have configured the Moderne CLI on your machine before you can run the following command.

shell

mod run . --recipe FindDeadData

To also set the recipe's optional settings, add them to the command. The values below are examples, not recommendations; see Options for what each one does.

With optional settings (example values)

mod run . --recipe FindDeadData --recipe-option "includeCopybookFields=true"

If the recipe is not available locally, then you can install it using:

RELEASE resolves to the newest release and LATEST to the newest build of any kind, including snapshots. Either one lets mod config recipes upgrade pull in later versions without editing this command; a pinned version stays where you put it.

RELEASE

mod config recipes jar install io.moderne.recipe:recipes-mainframe:RELEASE

LATEST

mod config recipes jar install io.moderne.recipe:recipes-mainframe:LATEST

Pinned version

mod config recipes jar install io.moderne.recipe:recipes-mainframe:0.1.0

Data tables

Dead data

io.moderne.mainframe.analysis.table.DeadData

Declared fields that nothing reads, and fields written but never read back.

Export after a run

mod study . --last-recipe-run \
  --data-table io.moderne.mainframe.analysis.table.DeadData

Column	Description
Program	The COBOL program.
Field	The field, qualified by the records containing it.
Section	Where it is declared. LINKAGE and FILE items are read and written by something outside this program, so they are reported separately rather than treated as unused.
Verdict	UNUSED for a field neither read nor written; DEAD_STORE for one written but never read back.
Picture	The declared picture, for sizing what would be saved by dropping it.
Copybook	The copybook the field came from, where it came from one. A field dead in this program may well be live in another that copies the same book, so a copybook field is only safe to drop once every program is checked.

Source files that had results

org.openrewrite.table.SourcesFileResults

Source files that were modified by the recipe run.

Export after a run

mod study . --last-recipe-run \
  --data-table org.openrewrite.table.SourcesFileResults

Column	Description
Source path before the run	The source path of the file before the run. null when a source file was created during the run.
Source path after the run	A recipe may modify the source path. This is the path after the run. null when a source file was deleted during the run.
Parent of the recipe that made changes	In a hierarchical recipe, the parent of the recipe that made a change. Empty if this is the root of a hierarchy or if the recipe is not hierarchical at all.
Recipe that made changes	The specific recipe that made a change.
Estimated time saving	An estimated effort that a developer to fix manually instead of using this recipe, in unit of seconds.
Cycle	The recipe cycle in which the change was made.

Source files that had search results

org.openrewrite.table.SearchResults

Search results that were found during the recipe run.

Export after a run

mod study . --last-recipe-run \
  --data-table org.openrewrite.table.SearchResults

Column	Description
Source path of search result before the run	The source path of the file with the search result markers present.
Source path of search result after run the run	A recipe may modify the source path. This is the path after the run. null when a source file was deleted during the run.
Result	The trimmed printed tree of the LST element that the marker is attached to.
Description	The content of the description of the marker.
Recipe that added the search marker	The specific recipe that added the Search marker.

Source files that errored on a recipe

org.openrewrite.table.SourcesFileErrors

The details of all errors produced by a recipe run.

Export after a run

mod study . --last-recipe-run \
  --data-table org.openrewrite.table.SourcesFileErrors

Column	Description
Source path	The file that failed to parse.
Recipe that made changes	The specific recipe that made a change.
Stack trace	The stack trace of the failure.

Recipe performance

org.openrewrite.table.RecipeRunStats

Statistics used in analyzing the performance of recipes.

Export after a run

mod study . --last-recipe-run \
  --data-table org.openrewrite.table.RecipeRunStats

Column	Description
The recipe	The recipe whose stats are being measured both individually and cumulatively.
Source file count	The number of source files the recipe ran over.
Source file changed count	The number of source files which were changed in the recipe run. Includes files created, deleted, and edited.
Cumulative scanning time (ns)	The total time spent across the scanning phase of this recipe.
Max scanning time (ns)	The max time scanning any one source file.
Cumulative edit time (ns)	The total time spent across the editing phase of this recipe.
Max edit time (ns)	The max time editing any one source file.