Ostrichpoll

⚠️ ⚠️ ⚠️ OSTRICHPOLL IS NO LONGER BEING ACTIVELY MAINTAINED.

Ostrichpoll is a tiny utility for monitoring Twitter Ostrich services. Effectively it can monitor any service which exposes internal metrics in JSON over HTTP.

Features:

• not a daemon: Ostrichpoll is intended to used by monit or a similar tool as part of a health check for a proper service
• validate multiple endpoints in a single execution
• specify normal ranges for metrics and gauges through YAML configuration
• support for "rate" measurements, specifying acceptable change per second for a metric. (useful for counters and other monotonic metrics)

$ gem install ostrichpoll

Ostrichpoll may be executed with a simple ostrichpoll which will ensure a 200 response is given from 127.0.0.1:9900/stats.json.

You may change the endpoint:

ostrichpoll -u devbox:9999/stats.json

The interesting part of Ostrichpoll is when you give a configuration file that specifies normal ranges for individual metrics:

ostrichpoll -c pollconfig.yml

Use -d to enable extra logging for debugging.

Configuration is specified in the format:

---
- url: 127.0.0.1:9900/stats.txt?period=10
  rate_file: /tmp/parmesan-http-ostrich-rate.yml
  validations:
    counters/KafkaEventSink_messageDropped:
      rate: true
      normal_range: [0, 5]
      missing: ignore
      exit_code: 2
      exit_message: "Message drop rate is too high"
    metrics/KafkaEventSink_append_msec/p99:
      normal_range: [0, 10]
      missing: error
      exit_code: 3
- url: 127.0.0.1:9901/stats.txt
...

• url - an endpoint which exposes JSON stats. If this endpoint is not available, Ostrichpoll will exit with -1 (really 255).
• rate_file - where to store rate measurements between executions of Ostrichpoll.
• validations - a list of validations to execute with the following options:
  • the key is the name of the metric. Nested metrics are supported through the / notation.
  • rate when set to true, compute the change per second since this value was last seen. You must specify a rate_file for this to work. Obviously, on the first execution of Ostrichpoll this validation will be ignored.
  • normal_range an array specifying the minimum and maximum (inclusive) values which are acceptable for this metric
  • missing behavior if the metric is not seen in the output at all. (error by default)
  • exit_code what value Ostrichpoll should exit with if this error is seen.
  • exit_message what Ostrichpoll should output to STDOUT if this error is seen. "OK" is the default (if no errors are encountered).

Ostrichpoll is setup to execute all validations on each execution. Even if one of the early validations fails, the output from all validations is logged to stderr. However, the exit code is the exit code from the first erroring validation.

Copyright 2012, Tumblr, Inc.

Licensed under the Apache License, Version 2.0 (the "License"); you may not use this file except in compliance with the License. You may obtain a copy of the License at http://www.apache.org/licenses/LICENSE-2.0

Unless required by applicable law or agreed to in writing, software distributed under the License is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the License for the specific language governing permissions and limitations under the License.