Changes between Version 2 and Version 3 of GENIEducation/SampleAssignments/CCNAssignment/ForInstructors


Ignore:
Timestamp:
05/29/13 14:35:16 (7 years ago)
Author:
shuang@bbn.com
Comment:

--

Legend:

Unmodified
Added
Removed
Modified
  • GENIEducation/SampleAssignments/CCNAssignment/ForInstructors

    v2 v3  
    113113  - '''Question 1.1 A: ''' [[BR]]
    114114  From ''researcher2'', fetch the same data again (from 1902/01/01 to 1902/01/02), and record the fetch times reported by ''client.py''. It prints out the time take to pull each temporary file along with the concatenation and write time. Then fetch 1902/02/03 to 1902/02/04, and record those fetch times. Fetch 1902/02/03 to 1902/02/04 a second time, and record the new times. Which transfer was longest, and which was shortest? Knowing that each ccnd caches data for a short period of time, can you explain this behavior?
     115  Outputs:
     116{{{
     117[shufeng@researcher2 ~]$ /opt/ccnx-atmos/client.py
     118Start Date in YYYY/MM/DD? 1902/01/01
     119End Date in YYYY/MM/DD? 1902/01/02
     120Asking for /ndn/colostate.edu/netsec/pr_1902/01/01/00, Saving to pr_1902_01_01.tmp.nc
     121Time for pr_1902_01_01.tmp.nc 0.228802204132=
     122Asking for /ndn/colostate.edu/netsec/pr_1902/01/02/00, Saving to pr_1902_01_02.tmp.nc
     123Time for pr_1902_01_02.tmp.nc 0.226236820221=
     124Joining files..
     125Concat + write time 0.0258860588074
     126Wrote to pr_1902_1_1_1902_1_2.nc
     127
     128
     129[shufeng@researcher2 ~]$ /opt/ccnx-atmos/client.py
     130Start Date in YYYY/MM/DD? 1902/02/03
     131End Date in YYYY/MM/DD? 1902/02/04
     132Asking for /ndn/colostate.edu/netsec/pr_1902/02/03/00, Saving to pr_1902_02_03.tmp.nc
     133Time for pr_1902_02_03.tmp.nc 0.661566972733=
     134Asking for /ndn/colostate.edu/netsec/pr_1902/02/04/00, Saving to pr_1902_02_04.tmp.nc
     135Time for pr_1902_02_04.tmp.nc 4.66726303101=
     136Joining files..
     137Concat + write time 0.0256381034851
     138Wrote to pr_1902_2_3_1902_2_4.nc
     139
     140
     141
     142[shufeng@researcher2 ~]$ /opt/ccnx-atmos/client.py
     143Start Date in YYYY/MM/DD? 1902/02/03
     144End Date in YYYY/MM/DD? 1902/02/04
     145Asking for /ndn/colostate.edu/netsec/pr_1902/02/03/00, Saving to pr_1902_02_03.tmp.nc
     146Time for pr_1902_02_03.tmp.nc 0.0416989326477=
     147Asking for /ndn/colostate.edu/netsec/pr_1902/02/04/00, Saving to pr_1902_02_04.tmp.nc
     148Time for pr_1902_02_04.tmp.nc 0.0415050983429=
     149Joining files..
     150Concat + write time 0.0257289409637
     151Wrote to pr_1902_2_3_1902_2_4.nc
     152}}}
     153  '''Answer:''' The first time fetching data from 2/3 to 2/4 took the longest, the 2nd time fetching data from 2/3 to 2/4 took the shortest time. [[BR]]
     154  Since ccnd caches data for a short period of time, the 2nd time researcher2 fetches data from 2/3 to 2/4, it fetches the data from local cache. Since researcher1 already caches data from 1/1 to 1/2, the `router` caches that data. As a result, researcher2 got the data from 1/1 to 1/2 from router cache.
    115155  - '''Question 1.1 B:''' [[BR]]
    116   Browse the content caches and interests seen on various hosts in the network by loading their ccnd status page on TCP port 9695 in your browser (see Section 5, Hints, below). Which hosts have seen interests and have content cached, and why?
     156  Browse the content caches and interests seen on various hosts in the network by loading their ccnd status page on TCP port 9695 in your browser (see Section 5, Hints, below). Which hosts have seen interests and have content cached, and why? [[BR]]
     157  '''Answer:''' datasource1, datasource2, router, researcher1 and researcher2 have seen interests and content cached. Since the data has passed them.
    117158
    118159