Идея простая: В статье разбирается стратегия кэширования stale-while-revalidate в Service Worker — подход, позволяющий мгновенно отдавать пользователю закэшированный контент и параллельно обновлять его в фоне. Рассмотрены сценарии применения (статика, API), потенциальные риски (устаревший HTML,…
A problem with the implementation of the new serve-stale feature in BIND 9.12 can lead to an assertion failure in rbtdb.c, even when stale-answer-enable is off. Additionally, problematic interaction between the serve-stale feature and NSEC aggressive negative caching can in some cases cause undesirable behavior from named, such as a recursion loop or excessive logging. Deliberate exploitation of this condition could cause operational problems depending on the particular manifestation -- either degradation…
BIND 9 resolver can crash when stale cache and stale answers are enabled, option `stale-answer-client-timeout` is set to a positive integer, and the resolver receives an RRSIG query. This issue affects BIND 9 versions 9.16.12 through 9.16.36, 9.18.0 through 9.18.10, 9.19.0 through 9.19.8, and 9.16.12-S1 through 9.16.36-S1.
If the `recursive-clients` quota is reached on a BIND 9 resolver configured with both `stale-answer-enable yes;` and `stale-answer-client-timeout 0;`, a sequence of serve-stale-related lookups could cause `named` to loop and terminate unexpectedly due to a stack overflow. This issue affects BIND 9 versions 9.16.33 through 9.16.41, 9.18.7 through 9.18.15, 9.16.33-S1 through 9.16.41-S1, and 9.18.11-S1 through 9.18.15-S1.