sensu-transport-snssqs-ng

sensu-transport-snssqs-ng is a Sensu transport that produces messages over Amazon SNS and consumes messages from Amazon SQS, providing simplified monitoring using Sensu.

Messages flow from hosts onto an Amazon SNS topic. It is up to the operator to ensure that messages from the SNS topic flow to one SQS queue for consumption by the Sensu server.

This project is forked from the the Simple team's project to add additional community-generated enhancements. It is intended to provide a superset of the upstream features.

Messages flow unidirectionally: from the monitored hosts to the Sensu server. In this diagram, an SNS topic is created for each monitoring environment. Hosts within these environments publish messages onto their environment's SNS topic. All of these SNS topics place messages onto a single SQS queue. This singular SQS queue is consumed by the Sensu cluster to act on messages.

• This transport is compatible with Sensu 0.23.0 and presumably, later versions.

• Subscription-based checks are not supported. Sensu subscriptions require the transport to be two-way: The Sensu server must be able to send a message through the transport to a specific host. SQS has no way of filtering messages in an SQS queue. Therefore, to use this transport, you can only use standalone checks.

• A slight (possibly inconsequential/imperceptible) performance increase can be gleaned by configuring SNS to publish to your SQS queue in "Raw" mode.

• This transport assumes that Sensu's process environment is properly configured to use the aws-sdk gem.

• By default, messages are buffered to reduce cost (up to 80% in some testing). This can be disabled via the buffer_messages setting.

To use this snssqs transport, this gem must be in your Sensu installation's ruby include path.

If you're installing Sensu via Chef, you can use the sensu_gem resource to ensure the gem is in Sensu's ruby include path:

sensu_gem 'sensu-transport-snssqs-ng' do
  action :install
end

Otherwise, if you're running Sensu via bundler, add this line to your Sensu installation's Gemfile:

gem 'sensu-transport-snssqs-ng'

That should place this gem into the include path.

First, we need to enable the snssqs transport. To do so, ensure that the following transport clause is in your configuration:

{
  "transport": {
    "name": "snssqs",
    "reconnect_on_error": true,
   }
}

Now that the SNSSQS transport has been enabled, configure it using an snssqs clause:

{
  "snssqs": {
    "max_number_of_messages": 10,
    "wait_time_seconds": 2,
    "region": "{{ AWS_REGION }}",
    "consuming_sqs_queue_url": "{{ SENSU_QUEUE_URL }}",
    "publishing_sns_topic_arn": "{{ SENSU_SNS_ARN }}"
    },
}

The following table lists possible settings and their descriptions. The values should be JSON strings unless specified otherwise.

• The buffer can be disabled using the buffer_messages option.

• Consecutive positive sensu check events (status=0) are skipped once the min amount of OK messages are sent (check_min_ok) and the maximum delay is not reached (check_max_delay).

• Negative sensu check events (status!=0) are sent all the time and are never skipped.

• Metrics are concatenated until the maximum size of the metrics buffer is reached (metrics_max_size) or the maximum delay is reached (metrics_max_delay).

• Metrics are summed up in a single sensu metric event with the name combined_metrics.

• The combined_metrics can contain multiple metrics of the same check with different timestamps. This is not a problem in a graphite like format where each line contains a key, value and timestamp.

sensu-transport-snssqs-ng is released under the Apache 2.0 License, full copy of which is inside of the LICENSE file.