Re: alto pids

Y. Richard Yang

Good discussions. I have reported it as a bug in In addition to reporting as a bug, which helps us to get priority, let's start some specific discussions.

What we need is a mechanism so that an admin can define the partition of hosts into PIDs. Let me give a try to start a strawman.

We can consider the hosts in the network as leaves in a graph. Each host also has a set of attributes (e.g., geolocation) beyond the graph properties. Hence, I assume that we need a mechanism to use these properties to group the hosts. A first idea coming to mind is cluster analysis ( 

Let me start with an anchor based approach. Assume that we allow the admin to define a set of anchors, where each anchor is a switch. 
   "netmap-grouping-alg": "nearest-anchor",

   "alg-metric": "hopcount",     // it could be "nearest geo-location", if we know

   "anchors": [ "sw1", sw3", "sw4"],

   "cost-map-cal-alg": "avg"   // cost from pid1 (sw1 cluster) to pid2 (sw2 cluster) is the average of host pairs
Then we can see that it defines three PIDs, where each PID is defined by an anchor in anchors. When an host is added, we can automatically compute which anchor is the nearest and hence assign it to it. We can prove that each PID is a connected component, if we assume the full graph is connected, when we consider graph hopcount. 

How to define a more general mechanism?


On Tue, Oct 20, 2015 at 12:51 PM, Gao Kai <gaok12@...> wrote:
Hi there,

Unfortunately current implementation doesn't support this.  My guess is that the developers of alto-hosttracker wrote this module mainly to support the Endpoint Cost Service instead of the Network Map/Cost Map so they didn't implement PID partition.  I'll forward your e-mail to confirm that.

However, in an internal meeting this July we did discuss about PID partition using hosttracker so I think there might be some progress on that.

Besides, you can report it as a bug by visiting  Since there are some major changes in the latest release and we have limited manpower, I can't really guarantee that this issue can be fixed soon enough. :(

We really appreciate your participation and we look forward to getting more feedbacks from you.  Thanks very much!


On 20/10/15 22:46, adenisiewicz@... wrote:
Is it possibility to define pids for the network created in mininet that is read by hosttracker-network-map? 
When I try, all hosts are grouped into one pid. 
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| Y. Richard Yang <yry@...>   |
| Professor of Computer Science       |

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