HB Blog 122: Android Tools For Analyzing RAM Usage.

Random-access memory (RAM) is a valuable resource in any software development environment, but it's even more valuable on a mobile operating system where physical memory is often constrained. Although both the Android Runtime (ART) and Dalvik virtual machine perform routine garbage collection, this does not mean you can ignore when and where your app allocates and releases memory. You still need to avoid introducing memory leaks, usually caused by holding onto object references in static member variables, and release any Reference objects at the appropriate time as defined by lifecycle callbacks.

Tools for analyzing RAM usage :-
Before you can fix the memory usage problems in your app, you first need to find them. Android Studio and the Android SDK include several tools for analyzing memory usage in your app,

1. The Device Monitor has a Dalvik Debug Monitor Server (DDMS) tool that allows you to inspect memory allocation within your app process. You can use this information to understand how your app uses memory overall. For example, you can force a garbage collection event and then view the types of objects that remain in memory. You can use this information to identify operations or actions within your app that allocate or leave excessive amounts of objects in memory. 
2. The Memory Monitor in Android Studio shows you how your app allocates memory over the course of a single session. The tool shows a graph of available and allocated Java memory over time, including garbage collection events. You can also initiate garbage collection events and take a snapshot of the Java heap while your app runs. The output from the Memory Monitor tool can help you identify points when your app experiences excessive garbage collection events, leading to app slowness.
3. Garbage collection events also show up in the Traceview viewer. Traceview allows you to view trace log files as both a timeline and as a profile of what happened within a method. You can use this tool to determine what code was executing when a garbage collection event occurred. 
4. The Allocation Tracker tool in Android Studio gives you a detailed look at how your app allocates memory. The Allocation Tracker records an app's memory allocations and lists all allocated objects within the profiling snapshot. You can use this tool to track down parts of your code that allocate too many objects.