2011/5/24 Sturla Molden <stu...@molden.no>: > Den 24.05.2011 11:55, skrev Artur Siekielski: >> >> PYRO/multiprocessing proxies isn't a comparable solution because of >> ORDERS OF MAGNITUDE worser performance. You compare here direct memory >> access vs serialization/message passing through sockets/pipes. > The bottleneck is likely the serialization, but only if you serialize large > objects. IPC is always very fast, at least on localhost .
It cannot be "fast" compared to direct memory access. Here is a benchmark: summing numbers in a small list in a child process using multiprocessing "manager": http://dpaste.org/QzKr/ , and using implicit copy of the structure after fork(): http://dpaste.org/q3eh/. The first is 200 TIMES SLOWER. It means if the work finishes in 20 seconds using fork(), the same work will require more than one hour using multiprocessing manager. > If a database is too slow, I am rather sure you need > something else than Python as well. Disk access is about 1000x slower than memory access in C, and Python in a worst case is 50x slower than C, so there is still a huge win (not to mention that in a common case Python is only a few times slower). Artur _______________________________________________ Python-Dev mailing list Python-Dev@python.org http://mail.python.org/mailman/listinfo/python-dev Unsubscribe: http://mail.python.org/mailman/options/python-dev/archive%40mail-archive.com
