Firebase 常見問題解答

什麼是 Firebase 項目？

項目是跨 iOS、Android 和 Web 應用程序的容器。它支持在跨平台應用程序之間共享數據庫、配置和通知等功能。

您應該將 iOS、Android 和 Web 應用變體添加到單個項目中。您可以使用多個項目來支持多種環境，例如開發、登台和生產。

如何將 Firebase 添加到現有的 Google Cloud 項目？

您可能必須通過管理的現有項目，谷歌雲端控制台或谷歌API控制台。默認情況下，這些項目都是在可見火力地堡控制台，但不認為是火力地堡項目。

要火力地堡添加到您現有的谷歌雲項目，單擊添加項目上的火力地堡控制台登陸頁面，然後選擇在項目名稱的菜單項目。

每個帳戶可以擁有多少個項目？

• Spark 定價計劃 — 您的項目配額僅限於少數項目（通常約為 5-10 個）。
• Blaze 定價計劃 - 只要您的 Cloud Billing 帳號信譽良好，您的每個 Cloud Billing 帳號的項目配額就會大幅增加。

項目配額限制是很少對大多數開發人員的關注，但如果需要的話，可以要求在項目中的配額增加。

請注意，完全刪除項目需要 30 天，併計入您的配額，直到完全刪除。

我可以在一個 Firebase 項目中擁有多少個 Firebase 應用程序？

Firebase 項目是跨 iOS、Android 和 Web 的 Firebase 應用的容器。 Firebase 將 Firebase 項目中的 Firebase 應用總數限制為 30。

在這個數字之後，性能開始下降（特別是對於 Google Analytics），最終，當應用程序數量增加時，某些產品功能將停止工作。此外，將 Firebase 應用添加到項目會創建一個或多個底層 OAuth 2.0 客戶端 ID。在單個項目中最多可以創建大約 30 個客戶端 ID。

從最終用戶的角度來看，您應該確保單個 Firebase 項目中的所有 Firebase 應用都是同一應用的平台變體。例如，如果您開發一個白標籤應用程序，每個獨立標記的應用程序都應該有自己的 Firebase 項目，但該標籤的 iOS 和 Android 版本可以在同一個項目中。參觀了解火力地堡項目，了解項目的火力地堡火力地堡和更多的應用程序的最佳實踐。

在極少數情況下，您的項目需要超過 30 個應用程序，您可以請求提高應用程序限制。您的項目必須在 Blaze 定價計劃中才能提出此請求。訪問谷歌雲端控制台，以使您的要求，並把它評估。了解更多關於配額管理的谷歌雲文檔。

在哪裡可以找到我的 Firebase 應用的應用 ID？

在火力地堡控制台，轉到您的settings項目的設置。向下滾動到你的應用程序卡，然後單擊所需的火力地堡App查看應用程序的信息，包括它的應用程序ID。

以下是一些示例 App ID 值：

• 火力地堡iOS應用： 1:1234567890:ios:321abc456def7890
• 火力地堡Android應用： 1:1234567890:android:321abc456def7890
• 火力地堡Web應用程序： 1:1234567890:web:321abc456def7890

將 Play/AdMob/AdWords/BigQuery 關聯到我的 Firebase 項目的先決條件是什麼？

• 用於連接您的Play帳戶，你需要既火力地堡項目所有者和Play帳戶所有者。
• 用於連接您的AdMob的應用程序，你需要一個雙方火力地堡項目業主和AdMob的管理員。
• 對於AdWords帳戶連結，你需要既火力地堡項目業主和AdWords管理員。
• 用於連接您的BigQuery項目，你需要的火力地堡項目業主。

我應該在我的應用程序中包含哪些開源聲明？

在 iOS 上，Firebase pod 包含一個 NOTICES 文件，其中包含相關條目。在火力地堡Android SDK中包含一個幫手Activity用於顯示的許可信息。

哪些瀏覽器支持訪問 Firebase 控制台？

Firebase 控制台可以從最新版本的流行桌面瀏覽器（例如​​ Chrome、Firefox、Safari 和 Edge）訪問。目前不完全支持移動瀏覽器。

為什麼 Firebase 控制台沒有為我加載？

如果您在加載 Firebase 控制台時遇到問題，請嘗試以下故障排除步驟：

1. 檢查的控制台排火力地堡狀態儀表板的任何可能的服務中斷。
2. 請確保您使用的是支持的瀏覽器。
3. 嘗試在隱身或私人窗口中加載 Firebase 控制台。
4. 禁用所有瀏覽器擴展。
5. 檢查是否有任何東西阻止了您的連接，例如防病毒軟件、網絡代理或防火牆。如果是這樣，請嘗試禁用它們。
6. 嘗試使用其他網絡或設備加載 Firebase 控制台。

如果上述決心的故障排除步驟的問題，那麼請與支持部門聯繫。

我的 Firebase 控制台語言是如何確定的？

對於火力地堡控制台的語言設置是基於你選擇的語言谷歌帳戶設置。

要改變你的語言首選項，請參閱更改語言。

Firebase 控制台支持以下語言：

• 英語
• 巴西葡萄牙語
• 法語
• 德語
• 印度尼西亞
• 日本人
• 韓國人
• 俄語
• 簡體中文
• 西班牙語
• 繁體中文

Firebase 控制台支持哪些角色和權限？

Firebase 控制台和 Google Cloud Console 使用相同的底層角色和權限。了解更多關於在角色和權限火力地堡IAM文檔。

火力支持基本（基本）的角色擁有者，編輯和查看器：

• 項目所有者可以將其他成員添加到項目中，建立集成（項目鏈接到BigQuery等或鬆弛的服務），並擁有該項目完整的修改權限。
• 一個項目編輯器對項目的完整的修改權限。
• 一個項目觀眾已經只讀了項目准入。請注意，Firebase 控制台當前不會對項目查看者隱藏/禁用編輯 UI 控件，但對於分配了查看者角色的項目成員，這些操作將失敗。

Firebase 還支持：

• 火力地堡預定義角色-策劃火力特定的角色，使比擁有者，編輯和閱讀器的基本角色更細粒度訪問控制。
• 自定義角色-完全自定義IAM角色創建到量身定制了一套符合組織的特定要求的權限。

哪些產品是付費的？哪些是免費的？

Firebase 的付費基礎架構產品包括實時數據庫、Firebase 雲存儲、函數、託管、測試實驗室和電話身份驗證。我們為所有這些功能提供免費套餐。

Firebase 還提供許多免費產品：分析、雲消息傳遞、通知編輯器、遠程配置、應用索引、動態鏈接和崩潰報告。您可以在所有計劃中無限量使用任何這些產品，包括我們的免費 Spark 計劃。此外，除電話身份驗證之外的所有身份驗證功能都是免費的。

我如何知道哪種定價計劃適合我？

Spark定價計劃

我們的 Spark 計劃是免費開發應用程序的好地方。您可以獲得所有免費的 Firebase 功能（Analytics、通知編輯器、Crashlytics 等）和大量付費基礎設施功能。但是，如果您在一個日曆月內超出了您的 Spark 計劃資源，您的應用程序將在該月剩餘時間內關閉。此外，使用 Spark 計劃時，Google Cloud 功能不可用。

Blaze 定價計劃

我們的 Blaze 計劃專為生產應用而設計。 Blaze 計劃還允許您使用付費的 Google Cloud 功能擴展您的應用程序。您只需為消耗的資源付費，從而可以根據需求進行擴展。我們努力使我們的 Blaze 計劃價格與行業領先的雲提供商競爭。

如何監控我的使用情況和計費？

您可以在 Firebase 控制台中的以下任一控制面板上跟踪項目資源的使用情況：

• 總體項目級使用和計費儀表板
• 驗證使用的儀表板（專為手機鑑權實例）
• 雲公司的FireStore使用儀表盤
• 雲功能的使用儀表盤
• 雲存儲使用儀表盤
• 主機使用儀表盤
• 實時數據庫使用儀表盤

Flame 定價計劃發生了什麼變化？

自 2020 年 1 月起，Flame 定價計劃（25 美元/月的額外配額）不再適用於新註冊。

• 現有的 Spark 和 Blaze 計劃項目以及任何新項目都不能再切換到或註冊 Flame 計劃。
• 如果您將現有的 Flame 計劃項目移動到不同的定價計劃，則該項目無法返回到 Flame 計劃。
• 現有的 Flame 計劃項目現在可以繼續使用 Flame 計劃。但是，您將在接下來的幾個月中收到有關遷移到另一個定價計劃所需時間表的信息。
• 對 Flame 計劃的引用已從文檔中刪除。

您對 Flame 計劃退休還有更多疑問嗎？閱讀部分的其他常見問題解答如下。

想了解 Firebase 提供的其他定價計劃嗎？請訪問我們的火力地堡定價頁面！如果你想開始移動任何現有的項目到另一個定價計劃，你可以做的是，在火力地堡控制台為您的項目。

關於 Flame 計劃退休的其他常見問題

Blaze 計劃中的免費使用量與 Spark 計劃中的免費使用量有何不同？

Blaze 計劃的免費使用量每天計算一次。使用限制也不同於 Cloud Functions、電話身份驗證和測試實驗室的 Spark 計劃。

對於 Cloud Functions，Blaze 計劃的免費使用量是在 Cloud Billing 帳號級別而非項目級別計算的，並且具有以下限制：

• 200 萬次調用/月
• 400K GB 秒/月
• 200K CPU-秒/月
• 5 GB 網絡出口/月

對於電話身份驗證，Blaze 計劃的免費使用量按月計算。

對於測試實驗室，Blaze 計劃的免費使用有以下限制：

• 30 物理設備分鐘/天
• 60 虛擬設備分鐘/天

當我從 Spark 計劃更改為 Blaze 計劃時，免費使用配額是否會重置？

Spark 計劃的免費使用包含在 Blaze 計劃中。轉向 Blaze 計劃時，免費使用量不會重置。

什麼是“同時數據庫連接”？

同時連接相當於連接到數據庫的一個移動設備、瀏覽器選項卡或服務器應用程序。 Firebase 對應用數據庫的同時連接數施加了硬性限制。這些限制是為了保護 Firebase 和我們的用戶免受濫用。

Spark 計劃限制為 100，不能提高。 Flame 和 Blaze 計劃的限制為每個數據庫 200,000 個同時連接。

此限制與您的應用程序的用戶總數不同，因為您的用戶不會同時連接。如果你需要超過20萬個並發連接，請閱讀使用多個數據庫規模。

如果我超出了實時數據庫的 Spark 計劃存儲或下載限制，會發生什麼情況？

為了向您提供可預測的價格，Spark 計劃中可供您使用的資源是有上限的。這意味著當您在任何月份超過任何計劃限制時，您的應用程序將被關閉以防止任何進一步的資源使用和額外費用。

如果我超過了實時數據庫的 Spark 計劃同時連接限制，會發生什麼？

當您的應用程序達到其 Spark 計劃的並發限制時，任何後續連接都將被拒絕，直到某些現有連接關閉。該應用程序將繼續為已連接的用戶工作。

如果我超出了 Cloud Storage 的 Spark 計劃上傳、下載或存儲限制，會發生什麼情況？

當您超出 Spark 計劃項目中 Cloud Storage 的限制時，結果取決於您超出的限制類型：

• 如果超過了GB存儲容量的限制，除非你刪除一些儲存或升級到提供更多的存儲空間，或無限的存儲空間計劃中的數據，你將不能夠更多數據存儲在該項目中。
• 如果超過了GB下載限制，您的應用程序將無法下載更多數據，直到第二天（從午夜開始，美國太平洋時間），除非你升級到一個計劃，限制較少的限制，或沒有任何限制。
• 如果超過了上載或下載操作的限制，您的應用程序將無法上傳或下載更多的數據，直到第二天（從午夜開始，美國太平洋時間），除非你升級到一個計劃，限制較少的限制，或者沒有限制。

Firebase 與 Google Cloud 的集成如何運作？

火力地堡被深深地集成谷歌的雲。項目在 Firebase 和 GCP 之間共享，因此項目可以啟用 Firebase 服務和 GCP 服務。您可以從 Firebase 控制台或 Google Cloud Console 訪問同一個項目。具體來說：

• 某些 Firebase 產品由 Google Cloud 直接支持，例如 Cloud Storage for Firebase。隨著時間的推移，由 Google Cloud 支持的產品列表將繼續增長。
• 您的許多設置（包括協作者和結算信息）都由 Firebase 和 Google Cloud 共享。您對 Firebase 和 Google Cloud 的使用會出現在同一張帳單上。

此外，當你升級到火焰的計劃，你可以使用任何谷歌雲世界一流的基礎設施作為一種服務和API，直接在你的火力地堡項目，以標準谷歌雲定價。您還可以將數據從 Google Cloud 直接導出到 BigQuery 進行分析。要了解更多信息，請參閱鏈接的BigQuery與火力地堡。

將 Google Cloud 與 Firebase 結合使用有許多增強安全性、改善延遲和節省時間的好處（與其他不在同一位置的雲服務相比）。退房的谷歌雲網站了解更多詳情。

如果我在 Google Cloud Console 中為該項目添加或移除結算帳號，我的 Firebase 項目會發生什麼情況？

如果將 Cloud Billing 帳號添加到 Google Cloud Console 中的項目，並且該項目當前在 Spark 計劃中，則該項目將自動升級到 Firebase Blaze 計劃。

相比之下，如果從 Google Cloud Console 中的項目中移除現有的有效 Cloud Billing 帳號，該項目將降級為 Firebase Spark 計劃。

我可以隨時升級、降級或取消嗎？

是的，您可以隨時升級、降級或取消。請注意，我們不為降級或取消提供按比例退款。這意味著，如果您在結算期結束前降級或取消，您仍需支付當月剩餘時間。

我會得到什麼樣的支持？

所有 Firebase 應用，包括那些使用免費計劃的應用，都在美國太平洋工作時間提供來自 Firebase 員工的電子郵件支持。所有帳戶都對計費相關問題、帳戶相關問題、技術（故障排除）問題和事件報告提供無限支持。

我可以限制 Blaze 計劃的使用量嗎？

不，您目前不能限制您的 Blaze 計劃使用量。我們正在評估支持 Blaze 計劃使用上限的選項。

Blaze 用戶可以為他們的項目或帳戶定義預算，並在他們的支出接近這些限制時收到警報。了解如何建立預算警報。

什麼是自動備份？你們提供每小時備份嗎？

自動備份對我們的火焰定價計劃為客戶提供先進的功能，備份，每天一次，並上傳到你的火力地堡實時數據庫中的數據谷歌雲存儲。

我們不提供每小時備份。

你們提供開源、非營利或教育折扣嗎？

我們的 Spark 計劃可供任何類型的個人或組織使用，包括非營利組織、學校和開源項目。由於這些計劃已經包含大量配額，因此我們不為開源、非營利或教育項目提供任何特殊折扣或計劃。

您是否提供企業合同、定價、支持或專用基礎設施託管？

我們的火焰計劃適用於各種規模的企業，我們的SLA達到或超過了雲基礎設施的行業標準。但是，我們目前不提供企業合同、定價或支持，也不為我們的實時數據庫等服務提供專用的基礎設施託管（即本地安裝）。我們正在努力添加其中一些功能。

你們提供臨時定價嗎？我只想要一兩個功能的現收現付。

我們在 Blaze 計劃中提供臨時定價，您只需為使用的功能付費。

付費 Firebase 計劃如何與廣告配合使用？付費計劃是否有免費的廣告積分？

Firebase 定價計劃與廣告分開，因此沒有免費的廣告積分。作為 Firebase 開發人員，您可以將您的 Ads 帳戶“關聯”到 Firebase 以支持轉化跟踪。

所有廣告活動都直接在 Ads 中管理，廣告計費是從 Ads 控制台管理的。

在哪裡可以找到有關 Firebase 隱私和安全的信息？

退房頁面中火力地堡隱私和安全。

Firebase SDK 是否會在 Analytics 之外記錄任何使用/診斷信息？

是的。這目前僅適用於 iOS，但將來可能會發生變化。在火力地堡的iOS SDK包括FirebaseCoreDiagnostics默認框架。 Firebase 使用此框架來收集 SDK 使用情況和診斷信息，以幫助確定未來產品增強功能的優先級。 FirebaseCoreDiagnostics是可選的，因此，如果您想選擇發送火力地堡診斷日誌時，你可以從你的應用程序解除鏈接庫這樣做。您可以瀏覽全部源代碼，包括記錄值，在GitHub上

A / B測試：有多少實驗可以創建和運行？

每個項目最多允許進行 300 個實驗，其中最多可以包含 24 個正在運行的實驗，其餘為草稿或已完成。

AdMob廣告：我能鏈接到我的Windows應用程序，以火力地堡？

不，目前不支持 Windows 應用程序。

AdMob廣告：為什麼我無法從火力地堡控制台鏈接我的應用程序的AdMob？

您可以通過 AdMob 控制台將 AdMob 應用關聯到 Firebase 應用。學習怎樣。

AdMob廣告：許可或訪問做什麼，我需要一個火力地堡的應用程序鏈接到AdMob應用？

為了進行此鏈接，您需要以下訪問權限：

• AdMob的：你需要一個AdMob的管理。
• 火力地堡：你必須有firebase.links.create許可，其中包括在所有者角色和火力地堡管理員角色。
• 谷歌Analytics（分析）：您必須具有編輯角色或管理與火力地堡項目相關的屬性用戶角色。了解更多。

AdMob廣告：可以在同一個AdMob帳戶鏈接AdMob應用和火力地堡應用多用戶？

對於多用戶AdMob帳戶，誰創造了第一火力地堡鏈接並接受用戶火力地堡服務條款是誰可以創建新的鏈接之間的AdMob應用和火力地堡應用的唯一用戶。

AdMob廣告：要使用AdMob，我應該使用火力地堡SDK適用於AdMob或谷歌移動廣告SDK？

• 對於iOS的項目，使用谷歌移動廣告SDK：
  pod 'Google-Mobile-Ads-SDK'
• 對於Android的項目，使用谷歌移動廣告SDK：
  implementation 'com.google.android.gms:play-services-ads:20.3.0'

  請注意，適用於 AdMob 的 Firebase Android SDK 可傳遞地包括適用於 Google Analytics 的 Firebase SDK。所以，如果您的應用程序調用的任何谷歌分析API和您切換到使用谷歌移動廣告SDK，請確保您明確添加依賴的火力地堡SDK為谷歌分析（ com.google.firebase:firebase-analytics ）應用程式的build.gradle文件。

• 對於C ++項目和統一的項目，按照各自的文檔中的說明。

分析：為什麼谷歌Analytics（分析）使用火力地堡產品的推薦一部分？

Google Analytics 是一種免費且無限制的分析解決方案，可與 Firebase 功能配合使用以提供強大的洞察力。它使您能夠查看 Crashlytics 中的事件日誌、FCM 中的通知有效性、動態鏈接的深層鏈接性能以及來自 Google Play 的應用內購買數據。它支持遠程配置、預測等中的高級受眾定位。

Google Analytics 作為 Firebase 控制台中的一個智能層，為您提供有關如何開發高質量應用、擴大用戶群和賺取更多收入的更可行的見解。

要開始，閱讀文檔。

分析：如何誰擁有I段的用戶還沒有遇到一些標準？

您可以通過“負面定位”這些用戶來重新定義問題。例如，重新界定的問題，因為“不顯示廣告，誰買東西的人”，並形成一個觀眾這些用戶的目標。

分析：如何控制我的分析數據是如何與火力地堡的其餘部分共享？

默認情況下，您的 Google Analytics 數據用於增強其他 Firebase 和 Google 功能。您可以隨時在項目設置中控制 Google Analytics 數據的共享方式。詳細了解數據共享設置。

分析：什麼是新的全面升級谷歌Analytics帳戶？

你可以閱讀更多有關新的谷歌Analytics（分析）在我們升級的博客文章。

分析：我怎麼知道，如果我使用谷歌分析的火力地堡或全面升級谷歌Analytics帳戶？

如果您在 Firebase 控制台的分析儀表板中看到“在 Google Analytics 中查看您的數據”的鏈接，那麼您的項目使用的是完全升級的 Google Analytics 帳戶。

您也可以通過查看檢查谷歌Analytics（分析）卡在火力地堡控制台（你可以訪問此settings >項目設置>集成，然後單擊管理）。 If you see a Linked Google Analytics account listed in the Your Google Analytics property section, your project is using the full Google Analytics experience in Firebase. If you do not see a Linked Google Analytics account , your project is using Google Analytics for Firebase.

Analytics: What will happen to my data when I upgrade to the new Google Analytics for Firebase?

This will not affect your existing Firebase project analytics data in the Firebase console.

You will be able to continue using the same dashboard and workflows you are using today, and you will also have access to some advanced features in Google Analytics.

Note that if you decide to enable cross-device reporting after making the upgrade, your data will be de-duplicated using the UserID. This may decrease some user counts in the Firebase console.

Analytics: What is Firebase User Segmentation Storage?

Firebase User Segmentation Storage stores audience lists you've created to provide targeting information to other Firebase services that use them, such as Crashlytics, FCM, Predictions, and more.

Analytics: Why don't I see any data after unlinking my app from Google Analytics?

Your analytics data resides within the Google Analytics property - not within the Firebase project. If you delete or unlink the property, then your data is unlinked from your project as well. The data still resides in that property, however, and you can always relink it to your project.
Creating a new Google Analytics account (and new property) will result in having a blank analytics dashboard in the Firebase console.

Analytics: Why do I get an error when trying to upgrade my project to the new Google Analytics experience?

If you are experiencing and error when upgrading, such as:

  The operation has failed (Reason: Requested entity
  already exists)
  

or

  The operation has failed (Reason: Precondition check failed)
  

This means that there is an association between your project and an already existing Google Analytics property. You can unlink the property, delete it, or upgrade through the Google Analytics interface.

If this is still an issue, you can use the REST API to unlink by using the removeAnalytics method , then use the addGoogleAnalytics method to link a new property.

You can then move the data from one property to another .

Analytics: Will audiences and/or events defined in Google Analytics be available on the Firebase console?

Your audiences and user properties will be synced. For some features, you'll need to use the Google Analytics interface, such as segmentation and closed funnels. You can access the Google Analytics interface directly via deep-links from the Firebase console. Any changes you make from the Firebase console can also be performed in Google Analytics, and those changes will be reflected in Firebase.

Analytics in my iOS app: Can I install Analytics without ad attribution and IDFA collection features?

Yes. See the Configure Data Collection and Usage page for more details.

App Indexing: Can Google Search index multiple languages for a single app?

Google Search supports the following multi-language cases:

• The associated website has unique URLs for each language, and there is one corresponding app HTTP URL for each web URL.
• The associated website has unique URLs for each language, but there is only one app HTTP URL. The app uses system language settings to display the correct language content.
• The associated website has one URL for all languages (or it supports only one language), and there is one corresponding app URL. The website and the application must display the content in the same language when the user has set no preference.

App Indexing: Can App Indexing support multiple websites for an app?

Yes. Make sure that each associated website is verified for the Android app via the Google Play Console . Learn how to verify your app .

App Indexing: Do sitemaps need to be added via the Search Console?

iOS does not require sitemaps, and Android does not require them as long as your app supports HTTP URLs. For custom URLs, you do not need to add sitemaps via Search Console. You can reference sitemaps in your robots.txt file and Google Search will use them. Learn more about managing sitemaps . However, submitting a sitemap through Search Console lets you see statistics on submitted and indexed HTTP URLs in Search Console.

Firebase Authentication: Which countries are supported for phone authentication?

Firebase Authentication supports phone number verification across the the world, but not all networks reliably deliver our verification messages. The following countries have good rates of delivery, and should be expected to work well for phone number sign in.

Cloud Messaging: What's the difference between the Notifications composer and Cloud Messaging?

Firebase Cloud Messaging provides a complete set of messaging capabilities through its client SDKs and HTTP and XMPP server protocols. For deployments with more complex messaging requirements, FCM is the right choice.

The Notifications composer is a lightweight, serverless messaging solution built on Firebase Cloud Messaging. With a user-friendly graphical console and reduced coding requirements, the Notifications composer lets users easily send messages to reengage and retain users, foster app growth, and support marketing campaigns.

Cloud Messaging: Apple announced they're decprecating the legacy binary protocol for APNs. Do I need to do anything?

No. Firebase Cloud Messaging swtiched to the HTTP/2-based APNs protocol in 2017. If you are using FCM to send notifications to iOS devices, there should be no action required on your part.

Cloud Messaging: Do I need to use other Firebase services in order to use FCM?

You can use Firebase Cloud Messaging as a standalone component, in the same manner as you did with GCM, without using other Firebase services.

Cloud Messaging: I am an existing Google Cloud Messaging (GCM) developer. Should I move to Firebase Cloud Messaging?

FCM is the new version of GCM under the Firebase brand. It inherits GCM's core infrastructure, with new SDKs to make Cloud Messaging development easier.

Benefits of upgrading to FCM SDK include:

• Simpler client development. You no longer have to write your own registration or subscription retry logic.
• An out-of-the-box notification solution. You can use the Notifications composer, a serverless notifications solution with a web console that lets anyone send notifications to target specific audiences based on insights from Google Analytics for Firebase.

To upgrade from GCM SDKs to FCM SDKs, see the guides for migrating Android and iOS apps.

Cloud Messaging: Why do my targeted devices apparently fail to receive messages?

When it looks like devices haven't successfully received messages, check first for these two potential causes:

Foreground message handling for notification messages . Client apps need to add message handling logic to handle notification messages when the app is in the foreground on the device. See the details for iOS and Android .

Network firewall restrictions . If your organization has a firewall that restricts the traffic to or from the Internet, you need to configure it to allow connectivity with FCM in order for your Firebase Cloud Messaging client apps to receive messages. The ports to open are:

• 5228
• 5229
• 5230

FCM usually uses 5228, but it sometimes uses 5229 and 5230. FCM does not provide specific IPs, so you should allow your firewall to accept outgoing connections to all IP addresses contained in the IP blocks listed in Google's ASN of 15169 .

Cloud Messaging: I have implemented onMessageReceived in my Android app, but it is not being called.

When your app is in the background, notification messages are displayed in the system tray, and onMessageReceived is not called. For notification messages with a data payload, the notification message is displayed in the system tray, and the data that was included with the notification message can be retrieved from the intent launched when the user taps on the notification.

For more information, see Receive and handle messages .

Notifications composer: What's the difference between the Notifications composer and Cloud Messaging?

The Notifications composer is a lightweight, serverless messaging solution built on Firebase Cloud Messaging. With a user-friendly graphical console and reduced coding requirements, the Notifications composer lets users easily send messages to reengage and retain users, foster app growth, and support marketing campaigns.

Firebase Cloud Messaging provides a complete set of messaging capabilities through its client SDKs and HTTP and XMPP server protocols. For deployments with more complex messaging requirements, FCM is the right choice.

Here's a comparison of the messaging capabilities provided by Firebase Cloud Messaging and the Notifications composer:

Notifications composer: I am an existing Google Cloud Messaging (GCM) developer, and I want to use the Notifications composer. What should I do?

The Notifications composer is an out-of-the-box solution that lets anyone send notifications to target specific audiences based on insights from Google Analytics for Firebase. Also, the Notifications composer provides funnel analysis for every message, allowing easy evaluation of notification effectiveness.

If you are an existing GCM developer, to use the Notifications composer you have to upgrade from GCM SDKs to FCM SDKs. See the guides for migrating Android and iOS apps.

Cloud Storage: Why can't I use Cloud Storage?

Cloud Storage for Firebase creates a default bucket in the App Engine free tier. This allows you to quickly get up and running with Firebase and Cloud Storage for Firebase, without having to put in a credit card or enable a Cloud Billing account. It also allows you to easily share data between Firebase and a Google Cloud project.

There are, however, two known cases where this bucket cannot be created and you will be unable to use Cloud Storage for Firebase:

• A project imported from Google Cloud which had a App Engine Master/Slave Datastore application.
• A project imported from Google Cloud which has domain prefixed projects. For example: domain.com:project-1234 .

There are currently no workarounds to these issues, and we recommend that you create a new project in the Firebase console and enable Cloud Storage for Firebase in that project.

Cloud Storage: Why do I see new service account IDs associated with my Firebase projects that use Cloud Storage?

Firebase uses service accounts to operate and manage services without sharing user credentials. When you create a Firebase project, you might notice that a number of service accounts are already available in your project.

If you used Cloud Storage before September 15, 2020, you may see the following legacy service account that is used to manage your bucket: firebase-storage@system.gserviceaccount.com .

After September 15, 2020, Cloud Storage for Firebase buckets may include an additional new service account: service-<project number>@gcp-sa-firebasestorage.iam.gserviceaccount.com .

You can view all service accounts associated with your project in the Firebase console, on the Service accounts tab .

Removing the new service account

We strongly discourage you from removing the new service account because if you do so, you will not be able to take advantage of upcoming security improvements.

However, if you prefer, you can disable the API or remove access from the new service account. Removing this account may block access to your Cloud Storage bucket from your apps.

Adding the new service account

If you removed the new service account or disabled the API and want to add them back, follow the instructions provided in Creating and managing service accounts for using the Google Cloud Console to add service-<project number>@gcp-sa-firebasestorage.iam.gserviceaccount.com to the set of service accounts for your project.

Crash Reporting: Why are there fewer crash reports in Analytics than Crash Reporting?

Crash Reporting creates a separate background process to upload crash info. If your app extends the Android Application class, you must ensure it is multi-process safe. Otherwise, it may cause concurrency issues. When an app extends an Application object, this object gets instantiated for each process in a multi-process app. Consider the following when adding Crash Reporting to your app:

1. If the implementation of this object accesses any out-of-process state (a database, the file system, shared preferences, etc), or performs other actions not safe for a multi-process environment, concurrency issues might arise. This is because multiple instances of the Application object may run simultaneously.
2. Many third-party libraries keep out-of-process state (eg in a local database) and are subject to the same concurrency issues if they are initialized from the Application object. If your app fits this description and you plan to use Crash Reporting in your app, we strongly encourage you to consider moving the Application logic to Content Providers, or to Android Activities. Any Application logic that is not safe for a multi-process environment can have unintended effects on your app.

Crash Reporting automatically exports captured errors to Google Analytics as app_exception events. Currently on Android, you may see a significant discrepancy between the number of Crash Reporting errors and Analytics app_exception events.

Dynamic Links: Why does my Android app access each Dynamic Link twice?

The getInvitation API clears the saved Dynamic Link to prevent it from being accessed twice. Be sure to call this API with the autoLaunchDeepLink parameter set to false in each of the deep link activities to clear it for the case when the activity is triggered outside the main activity.

Hosting: Why does my Hosting release history table in the Firebase console show file counts that are more than what my local project actually has?

Firebase automatically adds extra files containing metadata about the Hosting site, and these files are included in the total file count for the release.

Hosting: What's the largest file size that I can deploy to Firebase Hosting?

Hosting has a maximum size limit of 2 GB for individual files.

We recommend storing larger files using Cloud Storage , which offers a maximum size limit in the terabyte range for individual objects.

Hosting: How many Hosting sites can I have per Firebase project?

The Firebase Hosting multisite feature supports a maximum of 36 sites per project.

Performance Monitoring: How many custom URL patterns can I create?

You can create up to 400 total custom URL patterns per app and up to 100 custom URL patterns per domain for that app.

Performance Monitoring: Why am I not seeing real time display of performance data?

To view real time performance data, make sure that your app uses a Performance Monitoring SDK version that's compatible with real time data processing.

• iOS — v7.3.0 or later
• Android — v19.0.10 or later (or Firebase Android BoM v26.1.0 or later)
• Web — v7.14.0 or later

Note that we always recommend using the latest version of SDK, but any version listed above will enable Performance Monitoring to process your data in near real time.

Predictions: I just added Google Analytics to my app. When should I expect to see predictions in the console?

Predictions are based on your users' behavior, and the more history that's available, the better. At a bare minimum, Firebase Predictions needs two weeks of data: one week of activity to train on, and then one week to see what that activity led to (churning, spending, etc.). Beyond the first two weeks, the quality of the predictions will typically increase as Predictions observes longer sequences of user activity.

Predictions: How long does it take for predictions to be made about a new user?

For an app that is already instrumented with Google Analytics and trained with baseline data, predictions can be made for new users as early as the next day after they start using the app.

Realtime Database: Why was my Realtime Database reported bandwidth lower than average between September 2016 and March 2017?

For our bandwidth calculations, we normally include SSL encryption overhead (based on layer 5 of the OSI model). However, in September 2016, we introduced a bug that caused our bandwidth reporting to ignore encryption overhead. This might have resulted in artificially low reported bandwidth and bills on your account for a few months.

We released a fix for the bug in late March 2017, returning bandwidth reporting and billing to their normal levels.

Realtime Database: What are the scaling limitations of the Realtime Database?

Each Realtime Database instance has limits on the number of write operations per second. For small writes, this limit is approximately 1000 write operations per second. If you are approaching this limit, batching operations using multi-path updates can help you achieve higher throughput.

In addition, each database instance has a cap on the number of simultaneous database connections . Our default limits are large enough for most applications. If you are building an app that requires additional scale, you may need to shard your application across multiple database instances for added scale. You may also consider Cloud Firestore as an alternative database.

Realtime Database: What can I do if I'm over my Realtime Database usage limits?

If you've received an email alert or notification in the Firebase console that you've exceeded your Realtime Database usage limits, you can address it based on the usage limit you've exceeded. To see your Realtime Database usage, go to the Realtime Database Usage dashboard in the Firebase console.

If you're over your download limit, you can upgrade your Firebase pricing plan or wait until your download limit resets at the start of your next billing cycle. To decrease your downloads, try the following steps:

• Add queries to limit the data that your listen operations return.
• Check for unindexed queries.
• Use listeners that only download updates to data — for example, on() instead of once() .
• Use security rules to block unauthorized downloads.

If you're over your storage limit, upgrade your pricing plan to avoid service disruptions. To reduce the amount of data in your database, try the following steps:

• Run periodic cleanup jobs.
• Reduce any duplicate data in your database.

Note that it may take some time to see any data deletions reflected in your storage allotment.

If you're over your simultaneous database connections limit, upgrade your plan to avoid any service disruptions. To manage simultaneous connections to your database, try connecting via users via the REST API if they don't require a realtime connection.

Remote Config: Why don't fetched values change the behavior and appearance of my app?

Unless you fetch values with fetchAndActivate() , values are stored locally but not activated. To activate fetched values so that they can take effect, call activate . This design lets you control when the behavior and appearance of your app changes, because you can choose when to call activate . After you call activate , your app source code determines when updated parameter values are used.

For example, you could fetch values and then activate them the next time a user starts your app, which removes the need to delay app startup while your app waits for fetched values from the service. Changes to your app's behavior and appearance then occur when your app uses the updated parameter values.

To learn more about the Remote Config API and usage model, see Remote Config API Overview .

Remote Config: I am making a lot of fetch requests while developing my app. Why doesn't my app always get the latest values from the service when it sends fetch requests?

During app development, you might want to fetch and activate configs very frequently (many times per hour) to let you rapidly iterate as you develop and test your app. To accommodate rapid iteration on a project with up to 10 developers, you can temporarily set a FirebaseRemoteConfigSettings object with a low minimum fetch interval ( setMinimumFetchIntervalInSeconds ) in your app.

Remote Config: How quickly does the Remote Config service return fetched values after my app sends a fetch request?

Devices usually receive fetched values in less than a second, and often receive fetched values in milliseconds. The Remote Config service handles fetch requests within milliseconds, but the time required to complete a fetch request will depend on the network speed of the device and the latency of the network connection used by the device.

If your goal is to make fetched values take effect in your app as soon as possible, but without creating a jarring user experience, consider adding calls to fetchAndActivate each time that your app does a full screen refresh.