Changes between Version 14 and Version 15 of GENIEducation/SampleAssignments/CCNAssignment/ForInstructors


Ignore:
Timestamp:
06/04/13 16:21:34 (6 years ago)
Author:
shuang@bbn.com
Comment:

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  • GENIEducation/SampleAssignments/CCNAssignment/ForInstructors

    v14 v15  
    180180   It seems that researcher2 got the data from datasource1 and datasource2 through router. Since there is some overlap in the time range (from 1902/01/28 until 1902/01/31), in theory, researcher2 should get the non-overlap data from datasource and the overlap data from router's cache. We can not really see the details from the GEMINI generated graphs.
    181181
    182  - '''3.2 Choosing Content Names'''  -- Files to download: [http://www.gpolab.bbn.com/experiment-support/CCNExampleExperiment/naming.rspec naming.rspec], [http://www.gpolab.bbn.com/experiment-support/CCNExampleExperiment/ccnx-atmos.tar.gz ccnx-atmos.tar.gz] [[BR]]
     182 - '''3.2 Choosing Content Names'''  -- Files to download: [http://www.gpolab.bbn.com/experiment-support/CCNExampleExperiment/ccn-naming-pc.rspec ccn-naming-pc.rspec], [http://www.gpolab.bbn.com/experiment-support/CCNExampleExperiment/ccnx-atmos.tar.gz ccnx-atmos.tar.gz] [[BR]]
    183183 This exercise will demonstrate the importance of naming in named data networking. As the term suggests, and as you saw in Task 1.1, routing in named data networking is performed based on content names. This means that content naming has a large impact on how consumers fetch the data they require, and naming structure can heavily influence how simple and efficient data requests may be. [[BR]]
    184184 The ''Atmos'' package uses content names in the namespace ''/ndn/colostate.edu/netsec'' to serve NetCDF data. The data is sliced by time, with the suffix pr_<year>/<month>/<day>/00 added to represent data for the specified date. Thus, clients can request precipitation data for a given day in history, or a range of days, by issuing an interest for the dates in question. The complete path for data relating to January 3, 1902 would be: ''/ndn/colostate.edu/netsec/pr_1902/01/03/00''
    185185  - '''Task 2.1: Granularity of naming''' [[BR]]
    186186  ''This task will require you to change granularity of content names used by the Atmos client and server for different use cases, and measure the resulting traffic changes.'' [[BR]]
    187   Create an experimental network using the ''naming.rspec'' RSpec [http://www.gpolab.bbn.com/experiment-support/CCNExampleExperiment/naming.rspec HERE] (Note: this experiment does not require using GEMINI to monitor the network). This RSpec creates a network of the same topology as the network used in Exercise 3.1, but does not start or install the Atmos server or client. You will be modifying and installing this software yourself. [[BR]]
     187  Create an experimental network using the ''ccn-naming-pc.rspec'' RSpec [http://www.gpolab.bbn.com/experiment-support/CCNExampleExperiment/ccn-naming-pc.rspec HERE] (Note: this experiment does not require using GEMINI to monitor the network). This RSpec creates a network of the same topology as the network used in Exercise 3.1, but does not start or install the Atmos server or client. You will be modifying and installing this software yourself. [[BR]]
    188188  Fetch the Atmos source from http://www.gpolab.bbn.com/experiment-support/CCNExampleExperiment/ccnx-atmos.tar.gz. You may fetch it directly to the testbed nodes you will be using, or to a local machine, as you prefer. You will have to copy the source code to the GENI nodes to build and run it in your experiment. [[BR]]
    189189  Build the Atmos source on hosts ''datasource1'' and ''datasource2'', as well as a collaborator or researcher node of your choice by entering the source directory and running ''make''. On ''datasource1'' and ''datasource2'', you will find a NetCDF data file in /tmp, named ''pr_19020101_060000.nc'' and ''pr_19020201_060000.nc'', respectively. On each of these hosts run the command ''ccninitkeystore'' and start the Atmos server with the following commands:
     
    559559   Under month-granularity, it took about 20 seconds to get data for one day as well as one month (since the granularity is one month, user needs to at least get one month worth of data even if he/she only needs one day). Under one-day granularity, it took about 4.5 seconds to get 1 day of data and 130 seconds to get one month of data.
    560560
    561  - '''3.3 Exploring the Impact of Caching''' -- Files to download: [http://www.gpolab.bbn.com/experiment-support/CCNExampleExperiment/cache.rspec cache.rspec]  [[BR]]
     561 - '''3.3 Exploring the Impact of Caching''' -- Files to download: [http://www.gpolab.bbn.com/experiment-support/CCNExampleExperiment/ccn-cache-pc.rspec ccn-cache-pc.rspec]  [[BR]]
    562562 For this exercise you will manipulate various caching parameters for the ccnd daemon and observe the effects on network efficiency. [[BR]]
    563563 A property of named data networking is that multiple requests for the same names may return the same data. This allows intermediate nodes to cache data from one request for a given name and return it for future requests of the same name, from the same client or even a different client. When multiple clients located near each other but far from the server in the network want the same data, a node near the clients may be able to service some clients without contacting the server. [[BR]]
     
    565565  - ''' Task 3.1: Opportunistic caching''' [[BR]]
    566566  ''This task will demonstrate the benefit of opportunistic caching for static data used repeatedly.'' [[BR]]
    567   Create a GENI slice using ''cache.rspec'' from [http://www.gpolab.bbn.com/experiment-support/CCNExampleExperiment/cache.rspec Here] (Note: this experiment does not require using GEMINI to monitor the network). This slice has only two hosts, a data source and a data consumer. The data source serves historical precipitation data using the Atmos server, which is static information. It has a long cache timeout for this reason — five minutes. The data consumer uses a shorter cache timeout of 60 seconds, and the link between the two emulates a moderate consumer broadband link. [[BR]]
     567  Create a GENI slice using ''ccn-cache-pc.rspec'' from [http://www.gpolab.bbn.com/experiment-support/CCNExampleExperiment/ccn-cache-pc.rspec Here] (Note: this experiment does not require using GEMINI to monitor the network). This slice has only two hosts, a data source and a data consumer. The data source serves historical precipitation data using the Atmos server, which is static information. It has a long cache timeout for this reason — five minutes. The data consumer uses a shorter cache timeout of 60 seconds, and the link between the two emulates a moderate consumer broadband link. [[BR]]
    568568   - '''Question 3.1 A''': [[BR]]
    569569   From the host consumer run ''/opt/ccnx-atmos/client.py'' to fetch data from 1902/01/21 through 1902/01/24, and time the total transaction. Within 60 seconds, fetch the same data again, and time it. After 60 seconds (but before 300 seconds have passed), fetch it a third time, and time that. What is the benefit of local caching (the second fetch)? Is there perceptible benefit from server-side caching (the third fetch) when data takes some time to generate? [[BR]]