a cloud native json schema database with durable reactors built on tikv and nats

• strongly typed with jsonschema
• durable execution inspired by k8s reconcilers
• declarative migrations
• fulltext search
• first class object manipulation cli

quickstart

go install .
docker compose up -d
apogy server

Let's create a model. The most simple model in apogy is a jsonschema. Let's also create an object of that model.

---
model: Model
id:    com.example.Book
val:
  properties:
    name:
      type: string
    author:
      type: string
  required:
   - name
---
model:  com.example.Book
id:     dune
val:
  name:   Dune
  author: Frank Herbert

apogy apply -f examples/quickstart.yaml

Try what happens when you violate the jsonschema

apogy apply -f - <<EOF
model:  com.example.Book
id:     dune
val:
  name:   11111111111
EOF

'/name' does not validate with schema://com.example.Book#/properties/name/type: expected string, but got number

The jsonschema does not explicitly set additionalProperties: false, so this model allows arbitrary other json keys. However, it won't be searchable.

query

we can search by any modelled property

apogy q 'com.example.Book(val.name="Dune", val.author="Frank Herbert")'

while you can specify multiple search terms, databases can really only run one term in O(1) and the rest is O(n). there is currently no automatic query planner, and i'm not sure if there should be one at all. statistic query planners are good for first impressions but can later degrade in production.

instead, order the filters manually by decreasing cardinality, the first filter should be the highest cardinality, meaning most specific, returning the fewest unique results.

in the above example we first specify name=Dune, which is in the world of books is very specific. There are only two books named Dune in the example dataset, so the next filter only needs to look at those 2.

optimistic concurrency

apogy does not support locking. instead fetch the object first, then send an update keeping the version key intact the server will reject the put if a different client has updated the object between the get and put.

this example will succeed because the persisted object version is 1

apogy apply -f - <<EOF
model:   com.example.Book
id:      dune
version: 1
val:
  name:   Dune 2000
  author: Frank Herbert
EOF

doing the same apply again is indempotent with no error, however trying to change the val while using an outdated version will fail

apogy apply -f - <<EOF
model:   com.example.Book
id:      dune
version: 1
val:
  name:   Dune 3000
  author: Frank Herbert
EOF

Failed to put object: 409: version is out of date