Creating event notifications


MC Hosted Collector?

If Monte Carlo hosts your collector, unfortunately this guide cannot be used. You must use the process outlined in S3 Events - Query Logs.

For resources that require configuring S3 events, the CLI can be used to automate the process.

To configure events using the CLI, follow these steps -

  1. Follow this guide to install and configure the CLI (requires >= 0.10.0).
  2. Enable event collection (airflow-logs, query-logs).
  3. Add events using add-events per bucket.

If enabling events for query-logs permissions to the bucket are still required.

Adding Events


This command creates and/or updates resources in your AWS account.

All such actions will echo details with the changes for your review and approval before executing.

Please use the command montecarlo integrations add-events to configure event notifications for a bucket.

At a high level, this command does the following (i.e. automating these steps):

  1. Creates an SNS topic if one does does not already exist in the account / region for Monte Carlo.
  2. Updates the policy from the topic in step 1 to allow the desired bucket to publish events.
  3. Creates or updates the SQS policy for the desired Monte Carlo event queue to allow sending message from the topic from step 1.
  4. Subscribes the desired Monte Carlo event queue to the topic from step 1.
  5. Updates or creates notification for the bucket with the topic from step 1 as the destination.

All these steps are idempotent, so if a permission or resource already exists it will not be duplicated.

This procedure is known as S3 SNS Fanout (S3 -> SNS -> SQS) and will allow you to reuse the topic.

For reference, see help for this command below:

$ montecarlo integrations add-events --help
Usage: montecarlo integrations add-events [OPTIONS]

  Setup S3 event notifications for a lake.

  --bucket TEXT                   Name of bucket to enable events for.

  --prefix TEXT                   Limit the notifications to objects starting
                                  with a prefix (e.g. 'data/').

  --suffix TEXT                   Limit notifications to objects ending with a
                                  suffix (e.g. '.csv').

  --topic-arn TEXT                Use an existing SNS topic (same region as
                                  the bucket). Creates a topic if one is not
                                  specified or if an MCD topic does not already
                                  exist in the region.

  --collector-aws-profile TEXT    Override the AWS profile use by the CLI for
                                  operations on SQS/Collector. This can be
                                  helpful if the resources are in different

  --resource-aws-profile TEXT     Override the AWS profile use by the CLI for
                                  operations on S3/SNS. This can be helpful if
                                  the resources are in different accounts.

  --event-type [airflow-logs|metadata|query-logs]
                                  Type of event to setup.  [default: metadata;

  --auto-yes                      Skip any interactive approval.  [default:

  --collector-id UUID             ID for the data collector. To disambiguate
                                  accounts with multiple collectors.

  --option-file FILE              Read configuration from FILE.
  --help                          Show this message and exit.
# Configure event notficiations for the entire bucket
$ montecarlo integrations add-events --bucket sample-bucket1

# Configure event notfications for s3://sample-bucket2/lake with a csv extension
$ montecarlo integrations add-events --bucket sample-bucket2 --prefix lake --suffix .csv

# Configure events for a bucket in a different account than the collector and skip any prompts
$ montecarlo integrations add-events --bucket sample-bucket3 --collector-aws-profile vendor --resource-aws-profile ds --auto-yes


Does the bucket have to be in the same account / region as the data collector?
It does not. You can specify multiple AWS accounts using the two profile flags. The region is derived.

How do I limit scope, filter, or have multiple notifications configured for a bucket?
Use the prefix and suffix flags.

Can I use an existing SNS topic?
Yes! Specify the ARN using the topic-arn flag. This topic must be in the same region as the desired S3 bucket.

Why does my subscription say "Pending confirmation"?
Subscriptions across accounts may not necessarily confirm right away. Please check back in 24 hours.

How do I handle a "Configuration is ambiguously defined" error?
This occurs due to an AWS limitation where multiple overlapping prefixes/suffixes are not supported. In this case, you can configure an event notification to trigger a routing Lambda that forwards the event or an SNS topic that multiple endpoints can subscribe to (fanout).