Keyspace notifications suna ba da damar ga clients su subscribe (ta hanyar Pub/Sub) zuwa events game da canje-canje ga keys — kamar madaidaicin key, share, ko expire. Suna ba da damar isa hankali ga canje-canje na data a cikin Redis, tare da event na expiration zama yanayi na musamman, mai amfani.
CONFIG SET notify-keyspace-events KEA
PSUBSCRIBE
PSUBSCRIBE
Kuna kunna notifications (notify-keyspace-events, zaɓi wanne events) da subscribe zuwa special channels: __keyevent@<db>__:<event> (events na nau'i, misali expired, tare da key da ta shafi) ko __keyspace@<db>__:<key> (events akan madaidaicin key).
The "expired" event is widely used as a TIMER/SCHEDULER:
→ set a key with a TTL; when it expires, you get notified → trigger an action
→ e.g. "order:123:hold" expires in 15 min → notification → release the held inventory
→ delayed jobs, session-expiry handling, scheduled actions without a separate scheduler
⚠️ Built on PUB/SUB → fire-and-forget: if no subscriber is connected when the event
fires, it's MISSED (not reliable/persistent). Don't rely on it for critical events.
⚠️ "expired" fires when the key is actually REMOVED (lazy/active expiration), which can
LAG behind the exact TTL time → not precise timing.
⚠️ Has overhead at high volume; for reliable event handling, use STREAMS instead.
Samuwar keyspace notifications yana da amfani isa hankali ga canje-canje na data a cikin Redis, ƙarfin da ke ba da damar wasu nau'ikan patterns masu dogon dogon jiya — kuma fahimtar iyakacin sa daidai yake da mahimmi.
Zaɓin zai ba da damar clients su subscribe zuwa events game da canje-canje na key (saiti, share, da musamman expirations) ta hanyar Pub/Sub, yana ba da damar Redis tunatar da aplikasyon lokacin da data ta canja.
Event na expiration musamman yana aiki pattern na gida, elegante: sa key domin ta expire bayan wani jiya, kuma expiration notification yana kara action (saki inventory da aka riko bayan lokacin riko, adawa session expiry, aiwatar da aiki da aka jidda), yana ba da halayen scheduled-action ba tare da wata tsarin schedule.
Samuwa yadda ake kunna notifications (notify-keyspace-events) da subscribe zuwa special keyevent/keyspace channels shine hanyar samu.
Dan gida, fahimtar agogewa shine mahimmi don amfani da haka sosai: saboda ya gina akan Pub/Sub, yana fire-and-forget (events ba tare da connected subscriber ba su rasa kaf — saboda haka ba aminci don mahimman events), expired event yana jiya exact TTL (yana kara lokacin key ya tashi da shi da lazy/active expiration, saboda haka lokaci bai kasance daidai ba), kuma yana da samari a babbar adadi — ma'ana don reliable event handling, Streams ko wata hanya ta fi kyau.
Ilimin nan yana inda sanu karɓa keyspace notifications don guaranteed delivery.
Tun da isa hankali ga canje-canje na Redis data (musamman expirations azaman timers) shine pattern mai amfani don jidda aiki da scheduling, kuma tun da keyspace notifications suna sakaita shi kuma tare da mahimman iyakacin aminci da lokaci (yana karba Pub/Sub's fire-and-forget nature), samuwa keyspace notifications — abin da suke, pattern na expiration-azaman-timer, da musamman agogewa — yana da dakaicin ami, abin da ke da mahimmanci a aikace don amfani da haka feature lokacin da iyakacin sa suke buƙatar hanya mafi aminci.