Changes between Initial Version and Version 1 of GENIExperimenter/Tutorials/iMinds/GettingStarted_PartII_ccn/Procedure/Execute

07/06/14 14:44:39 (8 years ago)
Vic Thomas



  • GENIExperimenter/Tutorials/iMinds/GettingStarted_PartII_ccn/Procedure/Execute

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     1= [wiki:GENIExperimenter/Tutorials/iMinds/GettingStarted_PartII_ccn/Procedure/Setup  Understanding the AM API using Content Centric Networking] =
     6<div style="text-align:center; width:495px; margin-left:auto; margin-right:auto;">
     7<img id="Image-Maps_5201305222028436" src="" usemap="#Image-Maps_5201305222028436" border="0" width="495" height="138" alt="" />
     8<map id="_Image-Maps_5201305222028436" name="Image-Maps_5201305222028436">
     9<area shape="rect" coords="18,18,135,110" href="./Setup" alt="" title=""    />
     10<area shape="rect" coords="180,18,297,111" href="./Execute" alt="" title=""    />
     11<area shape="rect" coords="344,17,460,110" href="./Finish" alt="" title=""    />
     12<area shape="rect" coords="493,136,495,138" href="" alt="Image Map" title="Image Map" />
     14<!-- Image map text links - End - -->
     19== 4 Wait for resources to be ready ==
     21You can tell whether your nodes are ''ready'' by using a script built on `omni` called `readyToLogin`.
     25<ol type='a'>
     26  <li>
     27    Please use the command:
     29readyToLogin -a AM_NICKNAME SLICENAME
     31where (as before) <tt>AM_NICKNAME</tt> and <tt>SLICENAME</tt> are your aggregate
     32manager nickname and your slice name (both found on your worksheet).
     33  </li>
     34  <li>If it reports that the sliver is not yet ready (for example, it might say that the status is "changing"), then wait a minute
     35or two and try again.  Once everything is complete, <tt>readyToLogin</tt>
     36will give output that should look something like this:
     39rschr's geni_status is: ready (am_status:ready)
     40User example logs in to rschr using:
     41        ssh  -p 32768 -i /Users/example/.ssh/geni_key_portal
     42User example logs in to collar using:
     43        ssh -p 32769 -i /Users/example/.ssh/geni_key_portal
     47  </li>
     51== 5 Trying out the CCN protocol ==
     53The `install` and `execute` services requested in our RSpec have
     54already started, and nodes in our experiment should be running the CCN (Content Centric Networking) protocol.  Our experiment consists of:
     55   * A data source (node {{{dsrc1}}} that holds precipitation data from the US National Oceanic and Atmospheric Administration (NOAA).
     56   * A researcher node {{{rsrchr}}} that gets data from the data source
     57   * A collaborator node {{{collab}}} that gets data from the researcher
     59Key features of the CCN protocol include:
     60   * Data is accessed by name.  In our case we use a program called client to get precipitation data by date range (e.g. precipitation between 1901/01/01 and 1901/01/02).
     61   * All nodes cache data for a certain period of time.   When a node receives a request for data, it checks its local cache.  If the data is in it's cache, it returns that data.  Otherwise, it forwards it on to its neighbor.
     63We verify this caching behavior by:
     64   * Logging into the researcher node and using the client program to get precipitation data for a certain date range.  The client displays how long it took to get the data.
     65   * Retrieving the same data again and noting how we get it much faster since it comes out of a cache.
     66   * Requesting data for different date range and see how long it took to retrieve the data.
     67   * Requesting the data again and noting it is retrieved much faster.
     69If you have time, you can repeat the above steps on the collaborator node.
     71Note: There is an [wiki:GENIExperimenter/Tutorials/GettingStarted_PartII_ccn/Procedure/Execute/GEMINI optional part] to this exercise that uses the GENI Desktop to visualize traffic on the links in our network.  There you can visualize which data requests went all the way to the data source (node {{{dsrc1}}}) and which data requests were fulfilled from a node's cache.
     73=== 5.1 Run the CCN application ===
     74 1. Log into the node {{{rsrchr}}} using the {{{ssh}}} command returned by {{{readyToLogin}}}.
     75 2. Once you are logged in, ask for precipitation data from 1 Jan 1902 to 2 Jan 1902:
     76     {{{
     77     $ /opt/ccnx-atmos/
     78     Start Date in YYYY/MM/DD? 1902/01/01
     79     End Date in YYYY/MM/DD? 1902/01/02
     80     }}}
     81 3. You should see output that looks like:
     82     {{{
     83     Asking for /ndn/, Saving to
     84     Time for 1.09802699089=
     85     Asking for /ndn/, Saving to
     86     Time for 4.65998315811=
     87     Joining files..
     88     Concat + write time 0.0735998153687
     89     Wrote to
     90     }}}
     91     Note that it took about 1.1 and 4.7 seconds respectively to retrieve data for Jan 1 and Jan 2
     92 4. Run the client again and request the same data.  This time your output should look like:
     93     {{{
     94     Asking for /ndn/, Saving to
     95     Time for 0.0423700809479=
     96     Asking for /ndn/, Saving to
     97     Time for 0.0388598442078=
     98     Joining files..
     99     Concat + write time 0.0237510204315
     100     Wrote to
     101     }}}
     102    Notice how much faster the data was retrieved this time.
     103 5. If time permits, log into the collaborator node {{{collab}}} and run queries from there.  (Pick dates in 1901 or 1902.) Notice different data retrieval times depending on whether the data came from the datasource, the cache at {{{rsrchr}}}, or the local cache.
     106=== 5.2 (Optional) Visualize experiment data flows ===
     107    To use the GENI Desktop to visualize the data flows in your network, continue with the instructions [wiki:GENIExperimenter/Tutorials/GettingStarted_PartII_ccn/Procedure/Execute/GEMINI here].
     112= [wiki:GENIExperimenter/Tutorials/iMinds/GettingStarted_PartII_ccn/Procedure/Setup Setup] =
     113= [wiki:GENIExperimenter/Tutorials/iMinds/GettingStarted_PartII_ccn/Procedure/Finish Next:  Finish] =