You are implementing the infrastructure for a web service on Google Cloud. The web service needs to receive and store the data from 500,000 requests per second. The data will be queried later in real time, based on exact matches of a known set of attributes. There will be periods where the web service will not receive any requests. The business wants to keep costs low. Which web service platform and database should you use for the application?

Cloud Run is an excellent choice for a web service with fluctuating request patterns, including periods of no requests, because it is serverless and scales to zero, meaning you only pay when your service is actively processing requests, keeping costs low. Cloud Bigtable is a high-throughput, low-latency NoSQL database ideal for storing and querying large amounts of data based on exact matches of attributes, as required by the real-time query needs. BigQuery is a data warehouse optimized for analytical queries over massive datasets, not for real-time transactional lookups based on exact matches. Compute Engine autoscaling managed instance groups provide virtual machines that incur costs even when idle (unless fully scaled to zero, which adds complexity), making them less cost-effective than Cloud Run for intermittent workloads.