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Archive types

An archive type describes a kind of archived data. Technically the PAS can archive any byte stream, but archive types carry the metadata the PAS needs — notably the reference-id type and the expiration period — and, for Avro, enable schema validation.

An archive type is identified by the coordinates (system, archive type name, version). Archive-type names are only unique within a system: two systems may both define an archive type named Decree.

There are two ways to make archive types known to a PAS instance.

Avro archive types are defined in an Archive Type Registry, which generates immutable Java binding artifacts. A PAS instance:

  1. Depends on the generated binding artifact for every archive-type version it must handle:

    <dependency>
        <groupId>ch.admin.bit.jme.archivetype.jme</groupId>
        <artifactId>decree-v3</artifactId>
        <version>3</version>
    </dependency>

    The PAS must know the schema of every archive-type version it archives. After defining a new version in the registry and merging it, add the dependency to the PAS before data is archived with that schema.

  2. Registers those versions at runtime via an ArchiveTypeProvider bean:

    @Component
    public class JmeArchiveTypeProvider implements ArchiveTypeProvider {
        @Override
        public List<Class<? extends SpecificRecordBase>> getArchiveTypeVersions() {
            return List.of(
                ch.admin.bit.jeap.processarchive.test.decree.v1.Decree.class,
                ch.admin.bit.jeap.processarchive.test.decree.v2.Decree.class,
                DecreeDocument.class,
                Diagram.class);
        }
    }

    Register the bean through src/main/resources/META-INF/spring/org.springframework.boot.autoconfigure.AutoConfiguration.imports.

Schema validation​

When the content type of the data is avro/binary, the PAS validates the data against the Avro schema selected by the coordinates (system / archive type / version). This ensures the data can be read back later. See Archive Type Registry for how schemas are defined and evolved.

Config-defined archive types​

Archive types that are not Avro-based are not schema-validated and must be listed in configuration (PAS 11+):

jeap:
  processarchive:
    registry:
      types:
        - archive-type: JsonExample   # (archive-type, system, version) is the key of an archive-type version
          system: JME
          version: 1
          expiration-days: 365        # retention, enforced via S3 lifecycle policy
          reference-id-type: ch.admin.bit.jeap.jme.JsonExampleReferenceId

reference-id-type can be chosen freely; it is used when building the SharedArchivedArtifactVersionCreatedEvent.