How can I write Apache Ignite cache entry to Apache Avro file?

Question

I am now working on a task which requires me to write Apache Ignite cache-stored data to Avro. Unfortunately I do not have an access to initial Java classes used for cache-stored objects creation. The only source I have is Apache Ignite (it's Java API). Cache Itself is presented as IgniteCache<Object, Object>. Actually each cache entry is a key-value pair where key is realized as an AffinityKey and value contains a project-related object. Cache entry looks as follows when converting it to JSON:

{
    "AffinityKey [key=1, affKey=1f1a11b-ba1e-1cd1-1c11-c11111ab1111]": {
        "version": null,
        "name": "Name 1",
        "description": "Description 1",
        "interests": [
            "int1",
            "int2",
            "int3",
            "int4"
        ],
        "hobbies": [
            "hobby1",
            "hobby2",
            "hobby3"
        ],
        "classId": 11111,
        "creator": "5b90fb41e0eb212c4736d186",
        "editorId": null,
        "logoConfigurationId": 85,
        "editTimeout": null,
        "active": false,
        "lastActionTime": {
            "year": 2020,
            "month": "MAY",
            "nano": 143000000,
            "monthValue": 5,
            "dayOfMonth": 18,
            "hour": 14,
            "minute": 1,
            "second": 4,
            "dayOfYear": 139,
            "dayOfWeek": "MONDAY",
            "chronology": {
                "id": "ISO",
                "calendarType": "iso8601"
            }
        },
        "status": "Attention required",
        "lastJobId": null
    }
}

Can somebody please advise on how can I serialize my Ignite cache entries to Avro? As I know Avro-schema is required for avro-serialization. For this I will need to know both name and type for each field captured in my cache entry. The only way I see for schema creation is to get both entry-key and entry-value represented as BinaryObject and then collect all field names and types. Having all the name-type pairs for object's fields it may be possible to manually construct some kind of json for further storing it in .asvc file.

Perhaps somebody can advise on a bit more 'elegant' solution?

Answer 1

Having an Ignite Cache Entry represented as a Map<BinaryObject, BinaryObject> (.withKeepBinary() should be used when requesting cache from Ignite) it is possible to extract the definition for each BinaryObject's field (field name + field type). Avro SchemaBuilder can be used further for avro schema generation.