In order to properly observe and track swatch-billable-usage, we must add logging in places where remittances are created/updated and published. When error cases occur we should alert on them from splunk.

Important fields to log: 

• org_id
• billing_account_id
• billing_provider
• current_total(snapshot total)
• billing_factor
• value
• product_id
• metric_id
• remittance_uuid
• aggregate_id
• remittance timestamp
• aggregate window timestamp

Areas to log:

 Normal flow:

• Create new billable_usage_remittance
• Create new aggregate
• Update status
• Publish aggregate

Error cases:

• Failures to save billable_usage_remittance
• Contract missing exception
• Other api failures from swatch-contracts

Alerts: 

• Customer not subscribed when no contract found (already exists)
• Billable_usage_remittances failing to save
• Consumer lag on tally-summary or billable-usage-hourly-aggregate topic