sockshop-notify-customers

SockShop notify customers

Requirements

Metrics

catalogue-queries-top1-1h = topk(1, round(increase(request_duration_seconds_count{job="kubernetes-service-endpoints", kubernetes_name="front-end", kubernetes_namespace="sock-shop", method="get", name="front-end", route=~"/catalogue/.*-.*-.*-.*-.*", service="front-end", status_code="200"}[1h])))
catalogue-db = kube_service_info{namespace="sock-shop", service="catalogue-db"}

Description

SockShop management decided that in order to increase income an advertising campaign should be launched. Each hour all customers will be sent a mail containing details about the most popular product in the company's catalogue. The management is hoping that will cause a snowball effect (the more people buy the more others are convinced that the product is worth buying). Some board members were not convinced that it'll be enough to bring the customers' attention. After discussing for a while everyone agreed that the product should be discounted.

To achieve this goal the catalogue-queries-top1-1h metric has been created:

1. request_duration_seconds_count{...}[1h] - counts requests for items during last hour, grouped by itemId
2. increase - the query from 1. accumulates result, but we're interested in its growth
3. round - mitigates the issues of increase
4. topk(1, ...) - selects the top 1 value

The metric is used in the most-popular-this-hour rule, which:

1. Awaits for the aforementioned metric
2. Checks the time constraint which will pass only once an hour
3. Submits a CreateSessionAction that creates an HTTP session
4. Retrieves the product's details by making a GET request with the HTTPSession object returned by the previous action
5. Submits a MySqlUpdateAction that updates the product's price
6. Submits a NotifyCustomersAction

Results

SockShop management can observe products popularity trends on a Grafana dashboard

Customers received an e-mail

The price in the shop has been updated