Requestreaches

Requestreaches is a metric used in distributed systems to quantify how far a client request propagates through a network of services. It measures the depth of processing the request experiences, defined as the maximum number of distinct processing nodes that handle the request from origin to completion, or until it is dropped or fails. Depending on implementation, it can be expressed as an integer count of hops or as a depth in a call graph.

Calculation and measurement are typically based on distributed tracing or log correlation. Tracing tools record the path of a request across services, allowing engineers to determine the longest chain of downstream calls. The requestreaches value can be tracked as inclusive depth (counting the origin) or exclusive depth (counting only downstream nodes). It may be computed for inbound requests, outbound requests, or both, and can be complemented by latency and error metrics for fuller analysis.

Variants and interpretations exist. Inbound requestreaches refers to how far a client request travels from the entry point into the system, while outbound requestreaches tracks how deeply a service propagates orrafts requests to downstream components. In asynchronous or message-driven architectures, the metric may reflect the maximum depth of processing across eventual paths rather than a single synchronous chain.

Limitations include dependence on accurate tracing data, handling of retries, caching, and fan-out patterns, which can inflate the apparent reach. As with other metrics, requestreaches is most informative when used alongside latency, throughput, and reliability indicators. See also distributed tracing, hop count, and service graph analysis.