docs: translated demo/feature-flags into ja

Author: Msksgm

content/ja/docs/demo/feature-flags.md

@@ -0,0 +1,51 @@
+---
+title: フィーチャーフラグ
+aliases:
+  - feature_flags
+  - services/feature-flag
+  - services/featureflagservice
+cSpell:ignore: loadgenerator OLJCESPC7Z
+default_lang_commit: e3ae3a294873ef7febe106a618e650872f4d1796
+---
+
+デモは、異なるシナリオのシミュレートするために利用できるいくつかのフィーチャーフラグを提供しています。
+これらのフラグは、[OpenFeature](https://openfeature.dev) をサポートするシンプルなフィーチャーフラグサービスの [`flagd`](https://flagd.dev) によって管理されます。
+
+フラグの値は、デモを起動している際に、<http://localhost:8080/feature> で提供されるユーザーインターフェースを通じて変更できます。
+このユーザーインターフェースを通じて値を変更すると、flagd サービスに反映されます。
+
+There are two options when it comes to changing the feature flags through the user interface:
+
+- **Basic View**: A user friendly view in which default variants (the same
+  options that need to be changed when configuring through the raw file) can be
+  selected and saved for each feature flag. Currently, the basic view does not
+  support fractional targeting.
+
+- **Advanced View**: A view in which the raw configuration JSON file is loaded
+  and can be edited within the browser. The view provides the flexibility that
+  comes with editing a raw JSON file, however it also provides schema checking
+  to ensure that the JSON is valid and that the provided configuration values
+  are correct.
+
+## Implemented feature flags
+
+| Feature Flag                        | Service(s)       | Description                                                                                               |
+| ----------------------------------- | ---------------- | --------------------------------------------------------------------------------------------------------- |
+| `adServiceFailure`                  | Ad Service       | Generate an error for `GetAds` 1/10th of the time                                                         |
+| `adServiceManualGc`                 | Ad Service       | Trigger full manual garbage collections in the ad service                                                 |
+| `adServiceHighCpu`                  | Ad Service       | Trigger high cpu load in the ad service. If you want to demo cpu throttling, set cpu resource limits      |
+| `cartServiceFailure`                | Cart Service     | Generate an error whenever `EmptyCart` is called                                                          |
+| `productCatalogFailure`             | Product Catalog  | Generate an error for `GetProduct` requests with product ID: `OLJCESPC7Z`                                 |
+| `recommendationServiceCacheFailure` | Recommendation   | Create a memory leak due to an exponentially growing cache. 1.4x growth, 50% of requests trigger growth.  |
+| `paymentServiceFailure`             | Payment Service  | Generate an error when calling the `charge` method.                                                       |
+| `paymentServiceUnreachable`         | Checkout Service | Use a bad address when calling the PaymentService to make it seem like the PaymentService is unavailable. |
+| `loadgeneratorFloodHomepage`        | Loadgenerator    | Start flooding the homepage with a huge amount of requests, configurable by changing flagd JSON on state. |
+| `kafkaQueueProblems`                | Kafka            | Overloads Kafka queue while simultaneously introducing a consumer side delay leading to a lag spike.      |
+| `imageSlowLoad`                     | Frontend         | Utilizes envoy fault injection, produces a delay in loading of product images in the frontend.            |
+
+## Feature Flag Architecture
+
+Please see the [flagd documentation](https://flagd.dev) for more information on
+how flagd works, and the [OpenFeature](https://openfeature.dev) website for more
+information on how OpenFeature works, along with documentation for the
+OpenFeature API.