This topic describes the product limits.
Application quantity limits
Each Alibaba Cloud account can create a total of 45 applications in the EMAS console. This total includes deleted applications.
If you reach this limit, see Application creation limit reached for more information.
Scope of fixes
Mobile Hotfix supports only the Android platform.
Mobile Hotfix supports Android 4.3 and later. If you use custom devices or systems, disable system-level JIT before integration.
Mobile Hotfix supports fixes for Java code, resource files, and .so files.
Mobile Hotfix can fix errors or adjust classes in existing features. It does not support adding new features.
Google Play policies state that applications cannot be modified, replaced, or updated by any method other than the Google Play update mechanism. Because of this policy, Android applications that integrate the Mobile Hotfix software development kit (SDK) may not be approved for publication on the Google Play marketplace. For more information, see the Google Play Policy Center.
Hardening and obfuscation
1. If your APK uses hardening, you may encounter technical challenges when you use Mobile Hotfix. These challenges can cause the following issues that cannot currently be resolved:
The class loader loads some classes from the patch successfully, but fails to load others. When a class fails to load, the class loader loads the corresponding class from the original APK. This can cause a crash or prevent the fix from taking effect.
The class loader fails to load a class from the patch and throws a java.lang.ClassNotFoundException, which causes a crash.
The class loader incorrectly loads a different class from the patch and throws a java.lang.IncompatibleClassChangeError, which causes a crash.
2. Consider the following points when you use hardening and obfuscation:
Mobile Hotfix supports general hardening methods. However, hardening solutions vary among providers and are constantly updated. If your application uses hardening, create the patch package before you apply hardening. You must also thoroughly test the patch.
Obfuscation and hardening are different. Hardening may include obfuscation and other special processing. If a patch works on an unhardened application but fails to find a method or class after hardening, check whether the unhardened package was obfuscated. First, apply standard obfuscation to your project. If the patch works on the obfuscated package, you can then proceed with hardening tests.
Billing
Billing is based on calls to the queryAndLoadNewPatch interface, not on patch publication. You can add a switch to control calls to this interface as needed.
To prevent malicious queries from rapidly increasing service costs, the service is billed based on the number of interface queries. Mobile Hotfix provides a daily quota of 20 free patch queries per device for each Alibaba Cloud account. Usage beyond this quota is billed at CNY 2 per 10,000 requests.
Supported resources: `res` resources and `asset` resources.
Patch package limits
The default maximum patch size is 30 MB.
Other limits
To obfuscate your code, use ProGuard.