Sending custom Ambari Metrics gives response 500

[#1]

I'm trying to work on sending a custom metric to the Ambari Metric collector. I've been following this extremely helpful blog. http://bryanbende.com/development/2015/07/31/ambari-metrics-part1-metrics-collector

Whenever I make a POST, however, I get a response 500 with this error:

"com.sun.jersey.api.MessageException: A message body reader for Java class org.apache.hadoop.metrics2.sink.timeline.TimelineMetrics, and Java type class org.apache.hadoop.metrics2.sink.timeline.TimelineMetrics, and MIME media type application/octet-stream was not found."

Followed by a list of compatible readers.

Here's what I'm posting (except as a string with no whitespace) - it's pulled straight from the example here https://cwiki.apache.org/confluence/display/AMBARI/Metrics+Collector+API+Specification

{
  "metrics": [
    {
      "metricname": "AMBARI_METRICS.SmokeTest.FakeMetric",
      "appid": "amssmoketestfake",
      "hostname": "ambari20-5.c.pramod-thangali.internal",
      "timestamp": 1432075898000,
      "starttime": 1432075898000,
      "metrics": {
        "1432075898000": 0.963781711428,
        "1432075899000": 1432075898000
      }
    }
  ]
}

The url I'm pointing at is http://<metrics-collector-host>:6188/ws/v1/timeline/metrics/

A few things I've tried:

• POSTing to both on the cluster I made from VMs to experiment with and with the official Hortonworks sandbox (as suggested in Bryan's tutorial - making sure port forwarding is set up). Neither works.
• Restarting Ambari Metrics
• Having Ambari Metrics run it's service check, which, from what I can tell, posts and gets a dummy metric. It worked fine.
• Doing a GET request. Get requests are successful and do return the requested metrics.
• Sending the POST from my local machine, the primary VM, and the VM that the metrics collector lives on.
• Editing the "hostname" field in the json doc to match what machine I'm sending from (though that seems as though it shouldn't matter)

Thanks in advance!

James

[#2]

@James Gaskin Can you check if this helps -

https://community.hortonworks.com/questions/25042/custom-metric-names-in-ambari-metrics.html

https://community.hortonworks.com/questions/31192/how-to-add-custom-kafka-metrics-via-ambari-metrics...

[#3]

Hi @Sagar Shimpi,

Thanks so much for the response. Unfortunately neither of those posts hits the same problem I'm having.

The first article, the author is getting a 200 response from his POST requests, whereas I'm getting a 500.

With the second article, I'm trying to create a completely custom metric, not monitor something from an existing service.

[#4 · Accepted solution]

It ended up being a problem with the way I was posting the JSON. I wasn't specifying in the header that it was a JSON file, so the server assumed it was type "application/x-www-form-urlencoded" rather than "application/json"

Sending this as a header (I'm using python requests) fixed it. {'Content-Type': 'application/json'}