More about Dgraph Alpha

Dgraph Alpha provides several HTTP endpoints for administrators, as follows:

• /health?all returns information about the health of all the servers in the cluster.
• /admin/shutdown initiates a proper shutdown of the Alpha.

By default the Alpha listens on localhost for admin actions (the loopback address only accessible from the same machine). The --bindall=true option binds to 0.0.0.0 and thus allows external connections.

Querying Health

You can query the /admin graphql endpoint with a query like the one below to get a JSON consisting of basic information about health of all the servers in the cluster.

query {
  health {
    instance
    address
    version
    status
    lastEcho
    group
    uptime
    ongoing
    indexing
  }
}

Here’s an example of JSON returned from the above query:

{
  "data": {
    "health": [
      {
        "instance": "zero",
        "address": "localhost:5080",
        "version": "v2.0.0-rc1",
        "status": "healthy",
        "lastEcho": 1582827418,
        "group": "0",
        "uptime": 1504
      },
      {
        "instance": "alpha",
        "address": "localhost:7080",
        "version": "v2.0.0-rc1",
        "status": "healthy",
        "lastEcho": 1582827418,
        "group": "1",
        "uptime": 1505,
        "ongoing": ["opIndexing"],
        "indexing": ["name", "age"]
      }
    ]
  }
}

• instance: Name of the instance. Either alpha or zero.
• status: Health status of the instance. Either healthy or unhealthy.
• version: Version of Dgraph running the Alpha or Zero server.
• uptime: Time in nanoseconds since the Alpha or Zero server is up and running.
• address: IP_ADDRESS:PORT of the instance.
• group: Group assigned based on the replication factor. Read more here.
• lastEcho: Last time, in Unix epoch, when the instance was contacted by another Alpha or Zero server.
• ongoing: List of ongoing operations in the background.
• indexing: List of predicates for which indexes are built in the background. Read more here.

The same information (except ongoing and indexing) is available from the /health and /health?all endpoints of Alpha server.