OOTI Talks 22-11-2006 18-Apr-19 Johan J. Lukkien, j.j.lukkien@tue.nl TU/e Informatica, System Architecture and Networking

Questions Where are failure models for? Relationships: (reliable) multicast vs TCP vs. general multicast problem (spanning tree approach) atomic/reliable multicast / reliable RPC vs. transactions 18-Apr-19 Johan J. Lukkien, j.j.lukkien@tue.nl TU/e Informatica, System Architecture and Networking

Advice Clear difference between assumptions, problem and solutions Prepare for time-problems 18-Apr-19 Johan J. Lukkien, j.j.lukkien@tue.nl TU/e Informatica, System Architecture and Networking

Comment The topics were well-prepared, but more than fits in an hour 18-Apr-19 Johan J. Lukkien, j.j.lukkien@tue.nl TU/e Informatica, System Architecture and Networking

Questions What do they (=google) do? (rather than how) abstract problem Where is the gain? i.e., why and how does the GFS system solve the suggested issues avoidance of single hotspot – file manager dispatches request asap Is GFS an overlay filesystem relying on local filesystems? “a chunk is a file”... 2 levels of files? 18-Apr-19 Johan J. Lukkien, j.j.lukkien@tue.nl TU/e Informatica, System Architecture and Networking

Advice Indicate the separate concerns ranking, storage, retrieval, crawling, name-space management, load balancing Explicitly name the problems, or picture them e.g., which typical operations are supported by a data structure Listeners read the slides less text, or slowly coming in or give enough time Give an operational idea of the problems, how many reads, writes etc., Semantics/terminology: file, chunk, block, .... ? 18-Apr-19 Johan J. Lukkien, j.j.lukkien@tue.nl TU/e Informatica, System Architecture and Networking

Comments I find the choice of topic very interesting; relationship between presented facts and underlying problems unclear I would have given the numbers first 18-Apr-19 Johan J. Lukkien, j.j.lukkien@tue.nl TU/e Informatica, System Architecture and Networking