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Stephen Eichler's blog

18

Nov

2014

The run on the event based Doubletree simulator is still underway. This run is set to 20 traces per autonomous system. This is up from the standard setting of one and makes the runs much longer.

Some runs on the non event based Doubletree simulator are also underway. This includes the window 500 setting which runs 500 traces simultaneously at each vantage point, then sends control information before repeating this process.

I have started work on my thesis. This included work on the Introduction and Background. I think I now need to say more about existing topology and black hole discovery systems.

11

Nov

2014

The event based simulator ran successfully using 20 traces per autonomous system, rather than one. It took quite a bit longer to run with this change. I have now set up a script to run the rest of the simulations at this setting. That has now been running for four days. There should only be one memory map build necessary as the Doubletree one it generated in the test was good and it only needs one more for Traceroute. The previous simulations took two minutes once built, so these might take something like 20 times longer or a bit more.

I have started to work out the structure of the thesis, and writing the introduction and background. The references automatically cite the authors and year in the text which I find much more cumbersome than numbered references. Adding so much extra text breaks up the flow of the document to the reader, so I hope that I can change the style.

I think that the students PhD conference went quite well, but I will have to wait and see what feedback I get.

04

Nov

2014

The non event based simulator runs of Doubletree completed and the results were converted into graphs. These were added to the PhD conference slides. These results are sensible and suggest that Doubletree may be useful in the many sources to few destinations case.

While this simulator was running it wasn't clear if further efficiency was required, so I borrowed the hash processing code from IS0 and ran it in a test program in preparation to replace the arrays used for stop set information in my current analysis. I may not need to do this now as the simulator runs finished on time.

The event based simulator IS0 runs that used 19000 ASes with one trace per AS also had their results graphed and added to the PhD conference slides. An initial investigation into whether IS0 can process 180000 traces using the same resources is also being carried out, with an initial run underway.

A new run of the black hole detector was initiated and the latest results were processed.

28

Oct

2014

Version control was added to the latest configuration of the event based Doubletree simulator. This simulator then had a sources windows mode added. This is when traces are executed in blocks and the up and coming block has control information sent to it just before it starts probing. This creates an economy of probe and control packets. This was achieved in the simulator, as huge savings over the basic mode of operation were achieved.

A bug in the non event based Doubletree simulator was corrected. It is now necessary to rerun these simulations. Information about where the program is up to is now printed out in the std error stream allowing one to know where it is up to. The simulations are taking a bit longer than before but seem to be running correctly.

The PhD conference talk was shortened to only include Megatree, as Doubletree is being rerun, and there is only room for one analysis in the time allocated.

21

Oct

2014

I found a bug in the non event based Doubletree simulator. I had noticed that the packet counts for the local stop set only case were lower than expected. After fixing the code I set several reruns going. This will affect the design of my PhD student conference slides depending on when the new results are ready. If it takes too long I can present the Megatree results instead of Doubletree.

I processed some more black hole detector results.

I designed a structural layout for my thesis. This included chapter titles and the problem addressed.

14

Oct

2014

My conference slides were updated to include a many sources to many destinations diagram of the situation that we wish to find out about. Also a stages count blurb was included to describe the stage information in the graphs. In particular, that there is no control information sent on the final stage as it would serve no purpose.

The event based simulator has been updated to use source windows to give it a more realistic approach to the many sources to few destinations scenario. Source windows involve dividing traces into equal sized blocks and only forwarding control information to the next block to be run. The traces in each block or window run simultaneously. Initially the changes did not compile easily, until a few type handling related bugs were ironed out. The first run is underway, so I will soon see if the results are sensible.

07

Oct

2014

One graph in the slides for the internal PhD conference has less categories than the others, so I updated the Megatree simulator and started a rerun to gather the extra data. The data required are the packet counts including control packets for the use of global information without local.

Further black hole data was downloaded from Planetlab and analysed. The analysis was upgraded to fix a minor problem with dealing with asymmetric load balancers. The counts of these will now be more accurate. The issue is that some nodes may occur at more than one TTL or hop count. If these multiple hop counts are determined then the simplified algorithm I use to determine if a Paris Traceroute stop point node is in a load balancer, will function better.

Keywords were added to the PAM paper, and then the paper was resubmitted.

01

Oct

2014

Results from the last non event based simulator run have been analysed and the graphs added to the PhD conference slide set. The graphs show simulation of many sources to few destination using the Traceroute multipath detection algorithm (load balancer) data. It contains effects of both the global inter-monitor data and the local intra-monitor data.

The churn paper has been further refined for PAM and submitted. This involved adjusting headings, adding keywords, moving table captions, setting letter paper and adding some address data.

Another run of the black hole detector has been finished and the results downloaded.

23

Sep

2014

Some simulator runs finished on Wraith and I downloaded the results. There are some problems with Wraith currently, but my results were unaffected. The simulator runs on Spectre are not quite finished. These will be included in the slides for the internal university PhD conference.

I have done more work on the slides for the university conference. This included reworking the introduction to Doubletree to make it briefer. It also included adding more results from the Doubletree and Megatree simulators.

I registered an abstract for PAM and am continuing to refine the paper that will be submitted soon.

17

Sep

2014

A new round of data collection has been kicked off in the black hole in load balancers detector. The data from the previous round has been processed.

Data from the Doubletree simulator that uses MDA data has been collected and made into graphs along with some of the Megatree data. Four of these graphs have been included in the slide set for the internal PhD conference.

A draft slide set for the PhD conference has been completed. The proposed title is “Doubletree and Megatree simulations with control packet cost analysis".