ProxyPass 'nocanon' flag: ambiguous query string handling

Goal: reduce costs for low‑traffic reverse‑proxy workloads

When deploying Apache HTTP Server as a lightweight reverse proxy for a low‑traffic service, the ProxyPass directive’s nocanon flag is often considered to avoid unnecessary URI canonicalization overhead. However, the documentation does not clarify how the flag treats the query string, especially with non‑ASCII or special characters.

Uncertainty remains about whether nocanon preserves the client‑supplied query string verbatim, or merely disables canonicalization while still applying percent‑encoding to certain components. This ambiguity could affect backend routing, caching, and security.

Key questions

• When nocanon is set, does Apache forward the query string exactly as received, or does it still apply percent‑encoding to characters that would normally be canonicalized?
• How does nocanon behave with non‑ASCII characters in the query string across different Apache 2.4.x releases?
• What impact does the ambiguous handling of the query string have on caching mechanisms and backend application expectations in a low‑traffic deployment?