sangria-slowlog - Sangria middleware to log slow queries.

SBT Configuration:

• last stable release:

libraryDependencies += "org.sangria-graphql" %% "sangria" % "<last version>"
libraryDependencies += "org.sangria-graphql" %% "sangria-slowlog" % "<last version>"

Usage

With middleware, Sangria provides a very convenient way to instrument GraphQL query execution and introduce profiling logic. sangria-slowlog provides a simple mechanism to log slow queries and show profiling information.

Library provides a middleware that logs instrumented query information if execution exceeds specific threshold. An example:

import sangria.slowlog.SlowLog
import scala.concurrent.duration._

Executor.execute(schema, query,
  middleware = SlowLog(logger, threshold = 10 seconds) :: Nil)

If query execution takes more than 10 seconds to execute, then you will see similar info in the logs:

# [Execution Metrics] duration: 12362ms, validation: 0ms, reducers: 0ms
#
# $id = "1000"
query Test($id: String!) {
  # [Query] count: 1, time: 2ms
  #
  # $id = "1000"
  human(id: $id) {
    # [Human] count: 1, time: 0ms
    name

    # [Human] count: 1, time: 11916ms
    appearsIn

    # [Human] count: 1, time: 358ms
    friends {
      # [Droid] count: 2, min: 0ms, max: 0ms, mean: 0ms, p75: 0ms, p95: 0ms, p99: 0ms
      # [Human] count: 2, min: 0ms, max: 0ms, mean: 0ms, p75: 0ms, p95: 0ms, p99: 0ms
      name
    }
  }
}

sangria-slowlog has full support for GraphQL fragments and polymorphic types, so you will always see metrics for concrete types.

In addition to logging, sangria-slowlog also supports graphql extensions. Extensions will add a profiling info in the response under extensions top-level field. In the most basic form, you can use it like this (this approach also disables the logging):

Executor.execute(schema, query, middleware = SlowLog.extension :: Nil)

After middleware is added, you will see following JSON in the response:

{
  "data": {
    "human": {
      "name": "Luke Skywalker",
      "appearsIn": ["NEWHOPE", "EMPIRE", "JEDI"],
      "friends": [
        {"name": "Han Solo"},
        {"name": "Leia Organa"},
        {"name": "C-3PO"},
        {"name": "R2-D2"}
      ]
    }
  },
  "extensions": {
    "metrics": {
      "executionMs": 362,
      "validationMs": 0,
      "reducersMs": 0,
      "query": "# [Execution Metrics] duration: 362ms, validation: 0ms, reducers: 0ms\n#\n# $id = \"1000\"\nquery Test($id: String!) {\n  # [Query] count: 1, time: 2ms\n  #\n  # $id = \"1000\"\n  human(id: $id) {\n    # [Human] count: 1, time: 0ms\n    name\n\n    # [Human] count: 1, time: 216ms\n    appearsIn\n\n    # [Human] count: 1, time: 358ms\n    friends {\n      # [Droid] count: 2, min: 0ms, max: 0ms, mean: 0ms, p75: 0ms, p95: 0ms, p99: 0ms\n      # [Human] count: 2, min: 0ms, max: 0ms, mean: 0ms, p75: 0ms, p95: 0ms, p99: 0ms\n      name\n    }\n  }\n}",
      "types": {
        "Human": {
          "friends": {
            "count": 1, "minMs": 358, "maxMs": 358, "meanMs": 358,
            "p75Ms": 358, "p95Ms": 358, "p99Ms": 358
          },
          "appearsIn": {
            "count": 1, "minMs": 216, "maxMs": 216, "meanMs": 216,
            "p75Ms": 216, "p95Ms": 216, "p99Ms": 216
          },
          "name": {
            "count": 3, "minMs": 0, "maxMs": 0, "meanMs": 0,
            "p75Ms": 0, "p95Ms": 0, "p99Ms": 0
          }
        },
        "Query": {
          "human": {
            "count": 1, "minMs": 2, "maxMs": 2, "meanMs": 2,
            "p75Ms": 2, "p95Ms": 2, "p99Ms": 2
          }
        },
        "Droid": {
          "name": {
            "count": 2, "minMs": 0, "maxMs": 0, "meanMs": 0,
            "p75Ms": 0, "p95Ms": 0, "p99Ms": 0
          }
        }
      }
    }
  }
}

All SlowLog methods accept addExtensions argument which allows you to include these extensions along the way.

With a small tweaking, you can also include "Profile" button in GraphiQL. On the server you just need to conditionally include SlowLog.extension middleware to make it work. Here is an example of how this integration might look like.

Apollo Tracing Extension

sangria-slowlog also supports apollo-tracing format for metrics. In order to enable the extension, just use ApolloTracingExtension middleware (or a shortcut SlowLog.apolloTracing).

Here is an example:

import sangria.slowlog.SlowLog

Executor.execute(schema, query, middleware = SlowLog.apolloTracing :: Nil)

OpenTracing Support

sangria-slowlog supports OpenTracing with OpenTracing middleware. In order to enable it, just use OpenTracing middleware (or a shortcut SlowLog.openTracing).

Here is an example:

import sangria.slowlog.SlowLog

Executor.execute(schema, query, middleware = SlowLog.openTracing() :: Nil)

You would need an implicit instance of a Tracer available in the scope.

In order to access field's span in the resolve function, you can use middleware attachment ScopeAttachment:

Field(..., resolve = ctx => {
  val parentSpan: Option[Span] = ctx.attachment[SpanAttachment].map(_.span)
  
  // ...
})

The middleware creates spans using OpenTracings startActive API, so you can inject the active span into a carrier, for instance an HTTP request, if resolving a field requires a network request, and follow the trace in the responding service.

License

sangria-slowlog is licensed under Apache License, Version 2.0.