Thank you both for the help. I really appreciate it. Graham, I'll try to be aware of that as a potential source of problems, thanks for the heads-up! I'm not sure if I'll go the Apache route, but if I do I'll let you now if I run into the problem.
Justin, what setup are you using on linode? Regards, -dougal On Oct 24, 8:49 pm, Graham Dumpleton <[EMAIL PROTECTED]> wrote: > On Oct 25, 5:31 am, "[EMAIL PROTECTED]" <[EMAIL PROTECTED]> wrote: > > > Yet another hosting query. > > > I've been looking for a hosting provider for a few days, looked > > through the old threads and the recommended hosts at webpy.org/hosts > > and have tentatively settled on grokthis with one of their VPS > > packages. Does anyone have any experience with them? Was it good, easy > > to set up? Does anyone particularly recommend a different host? > > I am still yet to get my head around how these VPS systems are > configured, but one thing to be a bit mindful of when selecting a VPS, > is how your memory usage limit is determined. > > If one has a standalone UNIX system, in general one looks at resident > private memory (RSS) and resident shared memory (SHR) and as a gauge > of how much memory processes are taking. The amount of overall virtual > memory that a process could use isn't really an issue until the > application actually uses it. > > For example, on Linux the OS by default sets asides 8MB as stack > memory for the main process thread as well as each subsequent thread > created by the application. Thus if you have 10 additional threads, > then that is 88MB virtual memory set aside. Note that this doesn't > mean your RSS will be that value as it will only allocate real memory > for that if actually required. > > Problem is that some VPS systems appear to work out your actual memory > limit based on what is the theoretical amount that a process could > use, which means the amount of virtual memory set aside for stacks is > an issue as the virtual memory will be counted towards your memory > limit in some way. > > Have seen this come up a few times lately where Apache was used to > host web applications and worker MPM especially was used. Since Apache > would by default create two child process each with 25 threads, the > virtual memory usage can be quite high. Because of this, these people > were finding very quickly that Apache would die through reaching their > memory limit even though the real amount of memory it was using hadn't > reached the limit. > > So, be careful not to get a VPS with too small a memory limit if you > want to use Apache with lots of threads and/or processes. Same may > apply for other applications as well to various degrees. > > Since 8MB for stack size for additional threads is probably a lot more > than required, non Linux systems often use only 512KB (MacOS X), you > can also use configuration to override the excessive default of Linux. > For some background on this general problem and configuring Apache in > particular to avoid problems see links in: > > http://groups.google.com/group/modwsgi/browse_frm/thread/5ace4e1c7721... > > Anyway, this is one oddity I have been paying attention to lately and > you have given me a great opportunity for brain dumping my > understanding of it so far. I may not truly understand it yet as don't > have access to VPS systems to play with, but getting there. Even so, > above may not be totally accurate picture just yet. :-) > > Graham --~--~---------~--~----~------------~-------~--~----~ You received this message because you are subscribed to the Google Groups "web.py" group. To post to this group, send email to [email protected] To unsubscribe from this group, send email to [EMAIL PROTECTED] For more options, visit this group at http://groups.google.com/group/webpy?hl=en -~----------~----~----~----~------~----~------~--~---
