Github user jerrypeng commented on a diff in the pull request:
https://github.com/apache/storm/pull/921#discussion_r47680553
--- Diff: docs/documentation/Resource_Aware_Scheduler_overview.md ---
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+# Introduction
+
+The purpose of this document is to provide a description of the Resource
Aware Scheduler for the Storm distributed real-time computation system. This
document will provide you with both a high level description of the resource
aware scheduler in Storm
+
+## Using Resource Aware Scheduler
+
+The user can switch to using the Resource Aware Scheduler by setting the
following in *conf/storm.yaml*
+
+ storm.scheduler:
âbacktype.storm.scheduler.resource.ResourceAwareSchedulerâ
+
+
+## API Overview
+
+For a Storm Topology, the user can now specify the amount of resources a
topology component (i.e. Spout or Bolt) is required to run a single instance of
the component. The user can specify the resource requirement for a topology
component by using the following API calls.
+
+### Setting Memory Requirement
+
+API to set component memory requirement:
+
+ public T setMemoryLoad(Number onHeap, Number offHeap)
+
+Parameters:
+* Number onHeap â The amount of on heap memory an instance of this
component will consume in megabytes
+* Number offHeap â The amount of off heap memory an instance of this
component will consume in megabytes
+
+The user also has to option to just specify the on heap memory requirement
if the component does not have an off heap memory need.
+
+ public T setMemoryLoad(Number onHeap)
+
+Parameters:
+* Number onHeap â The amount of on heap memory an instance of this
component will consume
+
+If no value is provided for offHeap, 0.0 will be used. If no value is
provided for onHeap, or if the API is never called for a component, the default
value will be used.
+
+Example of Usage:
+
+ SpoutDeclarer s1 = builder.setSpout("word", new TestWordSpout(), 10);
+ s1.setMemoryLoad(1024.0, 512.0);
+ builder.setBolt("exclaim1", new ExclamationBolt(), 3)
+ .shuffleGrouping("word").setMemoryLoad(512.0);
+
+The entire memory requested for this topology is 16.5 GB. That is from 10
spouts with 1GB on heap memory and 0.5 GB off heap memory each and 3 bolts with
0.5 GB on heap memory each.
+
+### Setting CPU Requirement
+
+
+API to set component CPU requirement:
+
+ public T setCPULoad(Double amount)
+
+Parameters:
+* Number amount â The amount of on CPU an instance of this component
will consume.
+
+Currently, the amount of CPU resources a component requires or is
available on a node is represented by a point system. CPU usage is a difficult
concept to define. Different CPU architectures perform differently depending on
the task at hand. They are so complex that expressing all of that in a single
precise portable number is impossible. Instead we take a convention over
configuration approach and are primarily concerned with rough level of CPU
usage while still providing the possibility to specify amounts more fine
grained.
--- End diff --
This paragraph describes the reasoning behind why we did this while the
next paragraph describes how to use it
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