-----BEGIN PGP SIGNED MESSAGE----- Hash: SHA1 On Sep 26, 2006, at 2:12 PM, Brad Knowles wrote:
> At 8:51 AM -0400 9/26/06, Elizabeth Schwartz wrote: > >> Another question: is there any parallelism of processing files >> in the out >> queue or are they done sequentially? > > By default, it's single-threaded -- but not really "sequential". It > has more to do with how the directory entries are written, and not > what you or I would think of as "sequential". > > There are ways to get more than one Outgoing queue runner working, > but that's a very non-standard configuration, and takes more work to > maintain. I would like to see Mailman move towards a hashed queue > mechanism (like postfix), so that it would be a lot easier to have > multiple Outgoing queue runners working at the same time. Actually, Mailman does implement a hashed queue of sorts for its queue runners. Every queue file is assigned a hash and a timestamp, encoded in the file name. The timestamp is so that qrunners can handle the files in FIFO order. The hash creates a "hash space" for when multiple qrunners are used per queue. In that case, each qrunner is responsible for a slice of the hash space, so that they can run concurrently without having to deal with expensive and tricky locks. Multiple qrunners are a supported configuration, although I believe their use is rare. In fact, qrunners can contend for list locks which can reduce their concurrency, but the OutgoingRunner is one place where write access to the list data isn't necessary and care was taken so that multiple OutgoingRunners could maximize their concurrency. (fyi: there is an end-case bug in the hash space algorithm in Mailman pre-2.1.9. I don't think anyone's ever hit it, but Mark found it through visual inspection of the code. Fixed in 2.1.9.) Cheers, - -Barry -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.4.5 (Darwin) iQCVAwUBRRl1X3EjvBPtnXfVAQIhmQP/cPjTBDgfrYn4slRBDh2GQP/V9asulO3W 3Mgy/v3VORA5LoLddZnpqZj9xA7OakkVtK8Z59IW38PUaeMphAL8fP9CcFxbIa9B 9GkCOgJBiavKCkzn9WqVAIIRrJSLgG+DIf8uhfDGRaSy6Wzp5xkb3YfdFDH/BNRM 4rNRnL2Hg+A= =Dksf -----END PGP SIGNATURE----- ------------------------------------------------------ Mailman-Users mailing list [email protected] http://mail.python.org/mailman/listinfo/mailman-users Mailman FAQ: http://www.python.org/cgi-bin/faqw-mm.py Searchable Archives: http://www.mail-archive.com/mailman-users%40python.org/ Unsubscribe: http://mail.python.org/mailman/options/mailman-users/archive%40jab.org Security Policy: http://www.python.org/cgi-bin/faqw-mm.py?req=show&file=faq01.027.htp
