expand_edge=false option causes all mutations to fail

[juls858]

If you suspect this could be a bug, follow the template.

• What version of Dgraph are you using?
  Dgraph version : v1.0.7
  Commit SHA-1 : f180344
  Commit timestamp : 2018-08-10 13:00:21 -0700
  Branch : HEAD

• Have you tried reproducing the issue with latest release?
  Yes

• What is the hardware spec (RAM, OS)?
  macOS High Sierra 10.13.6
  16 GB RAM
  Docker Version 18.06.0-ce-mac70 (26399)

• Steps to reproduce the issue (command/config used to run Dgraph).
  Create new Dgraph instance with --expand_edge=false. This issue only occurs when this option is used on the initial run and with a new docker volume.

docker_compose.yml:

services:
  zero:
    image: dgraph/dgraph:latest
    volumes:
      - type: volume
        source: dgraph
        target: /dgraph
        volume:
          nocopy: true
    ports:
      - 5080:5080
      - 6080:6080
    restart: on-failure
    command: dgraph zero --my=zero:5080
  server:
    image: dgraph/dgraph:latest
    volumes:
      - type: volume
        source: dgraph
        target: /dgraph
        volume:
          nocopy: true
    ports:
      - 8080:8080
      - 9080:9080
    restart: on-failure
    command: dgraph server --expand_edge=false --my=server:7080 --lru_mb=4096 --zero=zero:5080
  ratel:
    image: dgraph/dgraph:latest
    volumes:
      - type: volume
        source: dgraph
        target: /dgraph
        volume:
          nocopy: true
    ports:
      - 8000:8000
    command: dgraph-ratel

volumes:
  dgraph:

Create a schema:

name: string @index(term) @lang .
age: int @index(int) .
friend: uid @count .

Insert data:

{
  set {
    _:michael <name> "Michael" .
    
  }
}

Result:

{
  "data": {
    "code": "Success",
    "message": "Done",
    "uids": {
      "michael": "0x1"
    }
  },
  "extensions": {
    "server_latency": {
      "parsing_ns": 13900,
      "processing_ns": 5005700
    },
    "txn": {
      "start_ts": 2,
      "keys": [
        "AAAEbmFtZQAAAAAAAAAAAQ=="
      ],
      "lin_read": {
        "ids": {
          "1": 7
        }
      }
    }
  }
}
-----
COMMIT ERROR (Firefox only):

{
  "errors": [
    {
      "code": "Error",
      "message": "Transaction has been aborted. Please retry."
    }
  ]
}

• Expected behaviour and actual result.
  I expect to be able to insert data or run a /MUTATE query
  All /MUTATE queries fail and are aborted.

[manishrjain]

Hey @danielmai , can you verify this bug?

[danielmai]

I'm able to reproduce the bug with the same Docker Compose file.

/mutate with the header X-Dgraph-CommitNow: true results in the transaction being aborted. The mutation succeeds without it.

/mutate

$ curl -i -XPOST http://localhost:8080/mutate -d '{
   set {
     _:michael <name> "Michael" .

   }
}'

HTTP/1.1 200 OK
Access-Control-Allow-Credentials: true
Access-Control-Allow-Headers: Content-Type, Content-Length, Accept-Encoding, X-CSRF-Token, X-Auth-Token, Cache-Control, X-Requested-With, X-Dgraph-CommitNow, X-Dgraph-LinRead, X-Dgraph-Vars, X-Dgraph-MutationType, X-Dgraph-IgnoreIndexConflict
Access-Control-Allow-Methods: POST, OPTIONS
Access-Control-Allow-Origin: *
Connection: close
Content-Type: application/json
Date: Thu, 23 Aug 2018 20:49:40 GMT
Content-Length: 233

{"data":{"code":"Success","message":"Done","uids":{"michael":"0x18"}},"extensions":{"server_latency":{"parsing_ns":15100,"processing_ns":3912800},"txn":{"start_ts":46,"keys":["AAAEbmFtZQAAAAAAAAAAGA=="],"lin_read":{"ids":{"1":93}}}}}

/mutate with X-Dgraph-CommitNow: true

$ curl -i -XPOST -H 'X-Dgraph-CommitNow: true' http://localhost:8080/mutate -d '{
  set {
    _:michael <name> "Michael" .

  }
}'
HTTP/1.1 200 OK
Access-Control-Allow-Credentials: true
Access-Control-Allow-Headers: Content-Type, Content-Length, Accept-Encoding, X-CSRF-Token, X-Auth-Token, Cache-Control, X-Requested-With, X-Dgraph-CommitNow, X-Dgraph-LinRead, X-Dgraph-Vars, X-Dgraph-MutationType, X-Dgraph-IgnoreIndexConflict
Access-Control-Allow-Methods: POST, OPTIONS
Access-Control-Allow-Origin: *
Connection: close
Content-Type: application/json
Date: Thu, 23 Aug 2018 20:50:12 GMT
Content-Length: 144

{"errors":[{"code":"ErrorInvalidRequest","message":"rpc error: code = Aborted desc = Transaction has been aborted. Please retry."}],"data":null}

[danielmai]

This happens on https://tour.dgraph.io as well.

1. Get a copy of the docker-compose.yml from the initial issue post with --expand_edge=false.
2. Run docker-compose up.
3. Click Run button on Load Schema step at https://tour.dgraph.io/intro/3/.
4. Click Run button on Load Data step at https://tour.dgraph.io/intro/4/.
5. Receive this response in the Response window:

{
  "errors": [
    {
      "code": "ErrorInvalidRequest",
      "message": "rpc error: code = Aborted desc = Transaction has been aborted. Please retry."
    }
  ],
  "data": null
}

[emersonwood]

I tested out the 1.0.8 release with expand_edge=false and then ran the test here: https://github.com/dgraph-io/dgraph/blob/master/contrib/integration/testtxn/main_test.go#L49

If I set CommitNow: true on the mutation, the transaction would abort when trying to mutate.

If I set CommitNow: false on the mutation, the transaction would abort when trying to commit manually.