Kibana: [APM] Requests per minute graph: Show "n/a" when `transaction.result` is empty

[formgeist]

Transactions with an empty transaction.result are shown on the graph, but has no label in the chart legend. The UI should show "n/a" as fallback value.

_Metrics page_

_Transactions page_

[elasticmachine]

Pinging @elastic/apm-ui

[formgeist]

It's also prevalent on the Transactions list page for the same chart

_Ruby agent example_

[formgeist]

It's can also be reproduced in 6.6 builds

[jasonrhodes]

transactions without result

Can you explain what that means, @formgeist ?

[formgeist]

@jasonrhodes We would assign transactions that didn't have a status_code a default name like "Transactions" i.e. for custom transaction types or not-HTTP transactions, so the legend would have a label in the chart. Derived from the default chart name as well "Transactions per minute".

[sqren]

This is not necessarily tied to to status codes. We derive the status code from transaction.result - which could actually be any string, eg "Success", "Fatal" etc.
Currently we don't handle it if the transaction.result field is empty (we do handle missing though!).

To find transactions without a result:

GET apm-*/_search
{
  "size": 20,
  "query": {
    "bool": {
      "filter": [
        {
          "term": {
            "processor.event": "transaction"
          }
        },
        {
          "term": { "transaction.result": "" }
        }
      ]
    }
  }
}

[sqren]

I'm not sure how we should solve this. I think the best option is to filter this data out.
It only happens for the ruby agent, so perhaps @mikker can help us out a little.

transaction.result is not required in apm-server intake but perhaps empty values should be disallowed?

[mikker]

I'm not sure how they occur either. @formgeist can you provide a sample document with an empty "" result?

[sqren]

@mikker Like this?

{
  "_index": "apm-7.0.0-2019.01.17",
  "_type": "_doc",
  "_id": "mp65XWgB8CmowIumbEdd",
  "_score": 1,
  "_source": {
    "parent": {
      "id": "8a9f48b069c5410a"
    },
    "processor": {
      "name": "transaction",
      "event": "transaction"
    },
    "observer": {
      "hostname": "01fe82bd5515",
      "id": "3403e42a-42ff-4eb3-bb80-308f41cba8b6",
      "ephemeral_id": "1ab19885-5a64-483d-ae2b-86c20654c644",
      "type": "apm-server",
      "version": "7.0.0"
    },
    "trace": {
      "id": "e7275157da263726c466edd0d4fd9902"
    },
    "@timestamp": "2019-01-17T21:30:54.950Z",
    "ecs": {
      "version": "1.0.0-beta2"
    },
    "host": {
      "name": "01fe82bd5515"
    },
    "context": {
      "request": {
        "headers": {
          "Accept": "*/*",
          "Version": "HTTP/1.1",
          "Connection": "keep-alive",
          "User-Agent": "python-requests/2.21.0",
          "Host": "opbeans-ruby:3000",
          "Accept-Encoding": "gzip, deflate",
          "Elastic-Apm-Traceparent": "00-e7275157da263726c466edd0d4fd9902-8a9f48b069c5410a-00"
        },
        "method": "GET",
        "http_version": "1.1",
        "socket": {
          "remote_addr": "172.18.0.8",
          "encrypted": false
        },
        "env": {
          "GATEWAY_INTERFACE": "CGI/1.2",
          "ORIGINAL_FULLPATH": "/api/types",
          "SERVER_PORT": "3000",
          "ROUTES_47181410207140_SCRIPT_NAME": "",
          "SERVER_PROTOCOL": "HTTP/1.1",
          "REQUEST_URI": "/api/types",
          "REMOTE_ADDR": "172.18.0.8",
          "ORIGINAL_SCRIPT_NAME": "",
          "SERVER_SOFTWARE": "puma 3.12.0 Llamas in Pajamas",
          "QUERY_STRING": "",
          "REQUEST_METHOD": "GET",
          "SCRIPT_NAME": "",
          "SERVER_NAME": "opbeans-ruby",
          "REQUEST_PATH": "/api/types",
          "PATH_INFO": "/api/types"
        },
        "body": "[FILTERED]",
        "url": {
          "search": "",
          "protocol": "http",
          "hostname": "opbeans-ruby",
          "port": "3000",
          "pathname": "/api/types",
          "full": "http://opbeans-ruby:3000/api/types"
        }
      },
      "process": {
        "pid": 82,
        "title": "/usr/local/bundle/bin/puma",
        "argv": [
          "-C",
          "config/puma.rb"
        ]
      },
      "system": {
        "hostname": "91150acafdbb",
        "ip": "172.18.0.11",
        "platform": "linux",
        "architecture": "x86_64"
      },
      "service": {
        "environment": "production",
        "agent": {
          "name": "ruby",
          "version": "2.0.1"
        },
        "framework": {
          "name": "Ruby on Rails",
          "version": "5.2.1"
        },
        "name": "opbeans-ruby",
        "runtime": {
          "name": "ruby",
          "version": "2.5.3"
        },
        "language": {
          "name": "ruby",
          "version": "2.5.3"
        },
        "version": "72676346748083292998b7b29bd2230cf246fc9b"
      }
    },
    "transaction": {
      "result": "",
      "duration": {
        "us": 1414
      },
      "name": "Rack",
      "span_count": {
        "dropped": {
          "total": 0
        },
        "started": 0
      },
      "id": "211c43b5f9791e39",
      "type": "request",
      "sampled": false
    },
    "timestamp": {
      "us": 1547760654950460
    }
  },
  "fields": {
    "@timestamp": [
      "2019-01-17T21:30:54.950Z"
    ]
  }
}

[sqren]

I'm not sure how they occur either.

How ironic. I wonder if we can use some apm tool to figure that out :D

[alvarolobato]

We agreed to use "n/a" for these case

[mikker]

Just to be clear: The UI will show "n/a" when the string is empty? I don't have to change anything, right?

[sqren]

Just to be clear: The UI will show "n/a" when the string is empty? I don't have to change anything, right?

No, you don't have to do anything. The UI will take care of empty transaction.result and displaying them as "n/a".

Although it might make sense to look into why transaction.result is sometimes empty for transactions sent by the ruby agent :)