[[["わかりやすい","easyToUnderstand","thumb-up"],["問題の解決に役立った","solvedMyProblem","thumb-up"],["その他","otherUp","thumb-up"]],[["わかりにくい","hardToUnderstand","thumb-down"],["情報またはサンプルコードが不正確","incorrectInformationOrSampleCode","thumb-down"],["必要な情報 / サンプルがない","missingTheInformationSamplesINeed","thumb-down"],["翻訳に関する問題","translationIssue","thumb-down"],["その他","otherDown","thumb-down"]],["最終更新日 2025-09-04 UTC。"],[],[],null,["# Create event-driven architectures with Eventarc\n===============================================\n\nYou can use [Eventarc](/eventarc/docs/overview) and\nFirestore with MongoDB compatibility to build\n[event-driven architectures](/eventarc/docs/event-driven-architectures).\nFirestore with MongoDB compatibility triggers for\nEventarc generate events from changes\nto a particular documents in your database. The trigger can route events to a\n[supported destination](/eventarc/docs/event-providers-targets):\n\n- Cloud Run functions (2nd gen) which supports the [Cloud Client Libraries](/firestore/docs/extend-with-functions-2nd-gen) and the [Firebase SDK](https://firebase.google.com/docs/firestore/extend-with-functions-2nd-gen)\n- [Cloud Run](/eventarc/docs/run/route-trigger-cloud-firestore)\n- [Google Kubernetes Engine](/eventarc/docs/gke/route-trigger-cloud-firestore)\n- [Workflows](/eventarc/docs/workflows/route-trigger-cloud-firestore)\n\nEventarc offers a standardized solution to manage the flow of\nstate changes, called *events*, between decoupled microservices. When triggered,\nEventarc routes these events to\nvarious destinations while managing delivery, security, authorization,\nobservability, and error-handling for you.\n| **Note:** Eventarc events use the [`CloudEvents`](https://cloudevents.io/) specification.\n\nLimitations\n-----------\n\nNote the following limitations for Firestore with MongoDB compatibility triggers for\nEventarc:\n\n- Ordering is not guaranteed. Rapid changes can trigger events in an unexpected order.\n- Events are delivered *at least* once.\n\n Make sure your event handler is idempotent and avoid producing unexpected results\n or side effects when an event is delivered more than once. Refer to\n [Building idempotent functions](https://cloud.google.com/blog/products/serverless/cloud-functions-pro-tips-building-idempotent-functions) to learn more.\n- A trigger is associated with a single database. You cannot create a trigger that matches multiple databases.\n\n- Deleting a database does not automatically delete any triggers for that database. The\n trigger stops delivering events but continues to exist until you [delete the trigger](/eventarc/docs/managing-triggers#trigger-delete). If the database is recreated, any associated triggers will also need to be deleted and recreated to restore event delivery.\n\n- Firestore with MongoDB compatibility supports Cloud Run functions (2nd gen) and doesn't support\n Cloud Run functions (1st gen).\n\n- Firestore Enterprise edition databases do not support Datastore entity event types.\n\nWhat's next\n-----------\n\n- Learn about [event-driven architectures](/eventarc/docs/event-driven-architectures)."]]
