It would seem that a new file is readable (sort of) before the tree is flushed, no ?
https://gist.github.com/1160026 -Drew ...deleted... > The simple answer is *new* Luwak files cannot be read while being >> written. This has to do with the fact that the HTTP interface does >> not expose a way to flush the file's tree to Riak before finishing the >> upload. The data for the file is being persisted, but the root >> pointer is not modified until the end. >> >> This also means that *existing* Luwak file *can* be read while being >> modified, but modifications made after the root pointer is found will >> be invisible. >> >> 4) Are there any latency numbers available, I am specifically looking at >>> the >>> time difference between the first byte read and the last byte write for >>> an >>> object. >>> >> I'm interpreting this question as, "After I finish writing, how long >> will it be before I can begin reading what I just wrote?" because of >> the tree-flushing behavior I described above. >> >> The answer depends on the backlog to the Luwak writer process (on the >> Riak/server side), and the depth of the resulting file tree. Once the >> writer has written the final block to an object, it must then flush >> the tree pointing to that object. Flushing the tree requires writing, >> at least, the root node and the "tld" object (where the metadata about >> the file is stored). The block_size and tree_order parameters >> (1,000,000 bytes and 250, by default) determine how many other nodes >> must be written between the root and the block. Each node is an >> additional Riak object write. >> >> I hope that helps, >> Bryan >> > > ______________________________**_________________ > riak-users mailing list > riak-users@lists.basho.com > http://lists.basho.com/**mailman/listinfo/riak-users_**lists.basho.com<http://lists.basho.com/mailman/listinfo/riak-users_lists.basho.com> > -- Drew Whitehouse ANU Supercomputer Facility Vizlab
_______________________________________________ riak-users mailing list riak-users@lists.basho.com http://lists.basho.com/mailman/listinfo/riak-users_lists.basho.com
