GCM（现在的FCM）是否可以免费获得任何限制？

Question

我想知道Firebase云消息传递对于无限用户是否免费？

Answer 1

In addition to the answer from AL.
From the Pricing page Faqs:

Which products are paid? Which are free?

Firebase's paid infrastructure products are the Realtime Database, Firebase Storage, Hosting, and Test Lab. We offer a free tier for all of these products except Test Lab.

Firebase also has many free products: Analytics, App Indexing, Authentication, Dynamic Links, Cloud Messaging, Notifications, Invites, Crash Reporting, &, Remote Config. You can use an unlimited amount of these in all plans, including our free Spark Plan.

So, it's free. The limit is not mentioned anywhere in the docs, however there's a limit on the Firebase realtime database, as mentioned in the FAQs:

Firebase imposes hard limits on the number of connections to your app's database at the same time. These limits are in place to protect both Firebase and our users from abuse.

The free plan limit is 100, and cannot be raised. The Flame and Blaze Plans have an initial limit of 10,000 simultaneous database connections. This is to prevent abuse and can be raised by contacting Firebase support with 24 hours notice.

This limit isn't the same as the total number of users of your app, because your users don't all connect at once. We encourage you to monitor your peak simultaneous database connections and upgrade if needed.

We're working hard to remove the initial 10,000 simultaneous connection cap on the Flame and Blaze plans.

So if you are using the Firebase Database to save your User's data and want to send a lot of Push Notifications to your user's devices using the FCM registration token stored in the Firebase Database, you might hit the limit in the free Spark plan, however it's really tough to hit the 10k limit.

Answer 2

来自Firebase Cloud Messaging Docs：

  

Firebase云消息传递（FCM）是一种跨平台的消息传递解决方案，可让您可以免费可靠地传递消息。

Answer 3

您可以参考官方Firebase Pricings页面。从那里，您将能够看到可用的项目类型： SPARK，FLAME，BLAZE ，所有这些项目都包含 FCM （以及Google Analytics ，应用程序索引，身份验证，动态链接，邀请，通知，崩溃报告和远程配置）免费提供。

Answer 4

Firebase云消息传递（FCM）连接服务器（CCS）位于设备和应用服务器之间。以下限制适用

1. 从文档here来看，似乎FCM确实并行地限制了1000个连接。

  

对于每个发件人ID，FCM允许并行1000个连接。

Sender Id是您创建Firebase项目时创建的唯一数字值，可在Firebase控制台“设置”窗格的“云消息传递”标签中找到。发件人ID用于标识可以向客户端应用程序发送邮件的每个应用服务器。

注意：如果此限制与应用服务器与CCS的最大连接无关，请纠正我

1. 其次，如果您使用的是XMPP conncetion服务器协议（如果使用设备到云消息传递则必须使用），您还应该阅读Flow Control。在任何单一时间点，CCS都不应有超过100条未经确认的消息。

  

如果待处理的消息计数达到100，则应用服务器应停止发送新消息并等待CCS确认某些现有的待处理消息

Answer 5

根据current documentation，Cloud Messaging Service（FCM）是免费的，没有限制。