question Re: Sending custom Ambari Metrics gives response 500 in Support Questions

Sending custom Ambari Metrics gives response 500

jgaskin — Sat, 02 Jul 2016 04:41:53 GMT

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

Re: Sending custom Ambari Metrics gives response 500

sshimpi — Sat, 02 Jul 2016 11:36:50 GMT

@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.html

Re: Sending custom Ambari Metrics gives response 500

jgaskin — Tue, 05 Jul 2016 23:51:33 GMT

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.

Re: Sending custom Ambari Metrics gives response 500

jgaskin — Fri, 08 Jul 2016 06:20:40 GMT

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'}