My comments are inlined.


On 12/28/11 11:48 PM, Gavan Hood wrote:

Thanks Avery,


I am asking questions up front ahead of jumping into the code.

I am looking  at embedded up to cloud scalability.


The  map slot approach hints that performance would be good on multi core machines compared to alternative graph approaches, is that a reasonable assumption.


This type of approach will work to utilize multiple cores, but there is probably some overhead form the Task Tracker and Job Tracker that could be avoided with some optimizations.

Do you have any idea of the performance trade off on a single core machine / laptop?


A single machine avoids the network I/O.  This is a good thing.  But it's limited to the speed/memory of the single machine rather that utilizing lots of machines.

Is the single machine support just for debug or could you build an application upon it.


You could do this, but remember that we have not optimized for this case.  That being said, there is no reason we can't tweak a couple of things to improve this.

Could you consider the above question for embedded systems (android  devices , iphone etc)

Is it PC and up technology or is it able to be configured for reasonable support on these devices.


I realise this applies to Hadoop as much as Giraph.

Yes, a lot of what I said would apply to Hadoop as well.

Perhaps the answer is in your response of not requiring Hadoop to run, does this mean there is an alternative or generic persistence model?

Giraph is a graph processing framework, not a persistent storage system.  You can store your data anyway you like (i.e. hard drive, flash drive, etc.)

If the embedded implementation is a problem, what is required to generate a back end for this size of device, has there been any thought on this side.


I haven't thought much about using Giraph on embedded devices.  I certainly wouldn't want to run graph processing applications on my phone.  Think about what that would do to my battery life =).





From: Avery Ching []
Sent: Thursday, 29 December 2011 1:07 AM
Subject: Re: stand alone implementation


Hi Gavan,

Giraph can run on a single machine as well as multiple machines, just like Hadoop.  Our test suite can be run with or without a running Hadoop instance as an example.

If you want to take advantage of multiple cores though, you might want to try running Hadoop with multiple map slots on the single node and then using the appropriate number of workers.

Hope that helps,


On 12/28/11 2:41 PM, Gavan Hood wrote:

Hi all,

I know the focus of giraph is multiple machines etc….

What if I want to scale down to single pc/ multiple cpu’s and even down to embedded systems.

Is this project and hadoop able to scale down as well as up ?