Hi folks, given that I started this interesting thread :-) I'll add a few considerations:
1\ Priority of passive port sharing ehnancement: Niklas survey shows that we are indeed in good company here, but it's problably worth having a better look at this anyway, there might be good technical reasons that led all the other teams not to support this or it may turn up that it's "simply" because it's somewhat hard to develop and test. 2\ Quick fix for 1.0.x codebase: pushing a 40x to the client when no passive port is available (or probably better: no passive port is available within X seconds) it's probably something we need to do anyway. 3\ Suspect race condition: the problem description for the originally reported http://issues.apache.org/jira/browse/FTPSERVER-359 (see also repro code attached to the jira) actually hints also to something different as well, in fact we state that a few (say 20) parallel threads issuing LISTs in passive mode are able to "lock-up" the server forever. Questions: 3.1\ Is this interely explained by this thread discussion? (I don't think so: the server should *always* be able to recover) 3.2\ Would this be fixed by a quick fix as per 2\? (likely, but it's sort of like using nukes to for mowing the lawn) In short my current position can be stated as follows: I think that FTPSERVER-359 has a different root cause from what we discussed, the problem impact is not completely known at the moment but it appears to *severely* affect the server availabily... having just one port is an easy way of reproducing it (but not the cause of it). What do you guys think? Cheers, F. On Thu, Mar 25, 2010 at 8:09 PM, Sai Pullabhotla < [email protected]> wrote: > Hmmm, if that's the case, it should be a low priority task for sure. > > Regards, > Sai Pullabhotla > > > > > > On Thu, Mar 25, 2010 at 2:06 PM, Niklas Gustavsson <[email protected]> > wrote: > > On Thu, Mar 25, 2010 at 7:42 PM, Sai Pullabhotla > > <[email protected]> wrote: > >> I think so. Overall, the idea is pretty cool, but too scary. You > >> mentioned that most FTP servers support this feature, but I could find > >> any servers highlighting this feature. > > > > I should not have said "most" since I have not investigated this > > myself. The report mentions "some commercial FTP-servers" whatever > > that means. > > > > A quick survey: > > IIS: one client per port, recommends using a large enoug range (Sai) > > FileZilla: one client per port, recommends using a large enough range > > proftpd: one client per port, recommends using a large enough range > > WS_FTP: seems to only support one client per port > > > > So, as mentioned in the issue, open source servers does seem to > > support this. Makes me think it might not be such high priority for > > us. > > > > /niklas > > >
