Service

It is used in example topologies (example_tree_4.yaml etc.,) in yaml_crds of TAAC repo.

This directory holds the "mock-service" component. It is a relatively simple HTTP server which follows instructions from a YAML file and exposes Prometheus metrics.

Usage

1. Include the entire topology YAML in /etc/config/service-graph.yaml
2. Set the environment variable, SERVICE_NAME, to the name of the service from the topology YAML that this service should emulate

Metrics

Captures the following metrics for a Prometheus endpoint:

• service_incoming_requests_total - a counter of requests received by this service
• service_outgoing_requests_total - a counter of requests sent to other services
• service_outgoing_request_size - a histogram of sizes of requests sent to other services
• service_request_duration_seconds - a histogram of durations from "request received" to "response sent"
• service_response_size - a histogram of sizes of responses sent from this service

Performance

Running on a GKE cluster with a limit of 1 vCPU and 3.75 gigabytes of memory, and logging set to INFO, this service can reach a maximum QPS of 12,000.