Re: 500.000+ users mailserver
Hello.. As i can see my post provoked few interesting answers. At the moment everything looks like that hypotetical 500.000+ mailserver could be implemented. There are just few remaining questions. If someone knows the answers then please share them :) a) how one can organize an independent quota system on OS with 16 bit uids. How to do it fast (as it'll be checked and modified on every delivery/download b) a lot of you is proposing netapp as a filesystem sharing solution. My question is : does it support 32 bit uids? if it does then does it implements any quota system on its own? How will it interoperate with an OS with 16 bit uids then etc. c) if we are using something like netapp then what network speed is necesary to make that 500k mailserver running smoothly (i assume netapp uses nfs). that's it. Kris
Re: 500.000+ users mailserver
listy-dyskusyjne Krzysztof Dabrowski wrote: Hello.. As i can see my post provoked few interesting answers. At the moment everything looks like that hypotetical 500.000+ mailserver could be implemented. There are just few remaining questions. If someone knows the answers then please share them :) a) how one can organize an independent quota system on OS with 16 bit uids. How to do it fast (as it'll be checked and modified on every delivery/download qmail-ldap checks user quotas indepently from the operating systems quota. b) a lot of you is proposing netapp as a filesystem sharing solution. My question is : does it support 32 bit uids? if it does then does it implements any quota system on its own? How will it interoperate with an OS with 16 bit uids then etc. Forget about using the OS' user management and go with an 'virtual user' system. c) if we are using something like netapp then what network speed is necesary to make that 500k mailserver running smoothly (i assume netapp uses nfs). Switched 100Mbit Ethernet. You can't make more traffic in the backend than you have in the front (= speed of your Internet connection). -- Andre Oppermann CEO / Geschaeftsfuehrer Internet Business Solutions Ltd. (AG) Hardstrasse 235, 8005 Zurich, Switzerland Fon +41 1 277 75 75 / Fax +41 1 277 75 77 http://www.pipeline.ch[EMAIL PROTECTED]
Re: 500.000+ users mailserver
Hi, Quoting listy-dyskusyjne Krzysztof Dabrowski ([EMAIL PROTECTED]): Hello.. As i can see my post provoked few interesting answers. At the moment everything looks like that hypotetical 500.000+ mailserver could be implemented. There are just few remaining questions. If someone knows the answers then please share them :) a) how one can organize an independent quota system on OS with 16 bit uids. How to do it fast (as it'll be checked and modified on every delivery/download No idea. I would use some homegrown script which checks the size of the pop mailboxes. I wouldn't want to depend on some flaky OS limitations. You'll never know which system call will bite you. b) a lot of you is proposing netapp as a filesystem sharing solution. My question is : does it support 32 bit uids? if it does then does it implements any quota system on its own? How will it interoperate with an OS with 16 bit uids then etc. A 740 supports 32767 in the local passwd. I would go with a different authentification service though. We have good experiences with LDAP. Replication is easy. c) if we are using something like netapp then what network speed is necesary to make that 500k mailserver running smoothly (i assume netapp uses nfs). Yes NFS. Depends. With multiple ethernet devices 100mbit full duplex should be enough if the pop3 servers are properly distributed. A NetApp supports gigabit ethernet if needed. Dirk
Re: 500.000+ users mailserver
Peter van Dijk [EMAIL PROTECTED] writes: On Wed, Mar 03, 1999 at 07:19:06PM +, Peter Gradwell wrote: Or is there a 32K+ limit on NIS user ids as well? ofcourse there is. NIS is just a way to manage your /etc/passwd centrally (no, don't start flaming now :) There is not a 32K limit on NIS user IDs. We currently have UIDs up to the 53000s in our NIS maps. -- Russ Allbery ([EMAIL PROTECTED]) URL:http://www.eyrie.org/~eagle/
Re: 500.000+ users mailserver
On Thu, Mar 04, 1999 at 03:10:36AM -0800, Russ Allbery wrote: Peter van Dijk [EMAIL PROTECTED] writes: On Wed, Mar 03, 1999 at 07:19:06PM +, Peter Gradwell wrote: Or is there a 32K+ limit on NIS user ids as well? ofcourse there is. NIS is just a way to manage your /etc/passwd centrally (no, don't start flaming now :) There is not a 32K limit on NIS user IDs. We currently have UIDs up to the 53000s in our NIS maps. You're right. What I meant to say was: NIS has the same limitations as your OS. If your OS limits uids at 64K, NIS won't limit you any further, neither will it help you break that barrier. Greetz, Peter. -- .| Peter van Dijk | mo|VERWEG stoned worden of coden .| [EMAIL PROTECTED] | mo|VERWEG dat is de levensvraag | mo|VERWEG coden of stoned worden | mo|VERWEG stonend worden En coden | mo|VERWEG hmm | mo|VERWEG dan maar stoned worden en slashdot lezen:)
Re: 500.000+ users mailserver
Peter van Dijk [EMAIL PROTECTED] writes: What I meant to say was: NIS has the same limitations as your OS. If your OS limits uids at 64K, NIS won't limit you any further, neither will it help you break that barrier. Right. If you're running SunOS, you do have to worry about 32K UIDs. And you still have to worry about 64K UIDs in most operating systems; support for larger things is pretty spotty. -- Russ Allbery ([EMAIL PROTECTED]) URL:http://www.eyrie.org/~eagle/
Re: 500.000+ users mailserver
On Wed, 03 Mar 1999 17:44:47 +0100, Krzysztof Dabrowski [EMAIL PROTECTED] said: K Hello. We are in the planing stage of a 500.000+ users mailserver (pop K smtp only, no shell's or anything). During our brainstorm we've came K to few questions: K We assume that every account will run on the same UID (to break 65k K uid's limit). If you're looking to handle this many mail accounts, I'd strongly recommend you use multiple servers. PCs aren't that expensive, especially since you don't need super-fast CPUs; you do need multiple fast drives and a decent network connection. If you had a "server farm" with (say) 10 PCs, you don't have to worry about UID limits, even with versions of Unix that don't support 32-bit UIDs. You also don't have to worry about putting all of your users out of business if one server goes down, and chores like backups become much easier. I don't know much about proxies; is there some nifty way for a user to connect to a large mail-server, have the server tell the user's machine "your mail is actually on server03", and then redirect the POP/SMTP requests to the correct PC without having all of the resulting traffic pass through one machine? This would allow you to load-balance by moving mail accounts around without inconveniencing the user. -- Karl Vogel ASC/YCOA, Wright-Patterson AFB, OH 45433, USA [EMAIL PROTECTED] or [EMAIL PROTECTED]
Re: 500.000+ users mailserver
At 2:13 pm -0500 3/3/99, [EMAIL PROTECTED] wrote: I don't know much about proxies; is there some nifty way for a user to connect to a large mail-server, have the server tell the user's machine "your mail is actually on server03", and then redirect the POP/SMTP requests to the correct PC without having all of the resulting traffic pass through one machine? This would allow you to load-balance by moving mail accounts around without inconveniencing the user. surely, if your user accounts are dealt with by NIS, and their home directories mounted via NFS, then it doesn't matter which of the cluster they connect to? Or is there a 32K+ limit on NIS user ids as well? Peter. -- peter at gradwell dot com; online @ http://www.gradwell.com/ "To look back all the time is boring. Excitement lies in tomorrow"
Re: 500.000+ users mailserver
On Wed, Mar 03, 1999 at 07:19:06PM +, Peter Gradwell wrote: At 2:13 pm -0500 3/3/99, [EMAIL PROTECTED] wrote: I don't know much about proxies; is there some nifty way for a user to connect to a large mail-server, have the server tell the user's machine "your mail is actually on server03", and then redirect the POP/SMTP requests to the correct PC without having all of the resulting traffic pass through one machine? This would allow you to load-balance by moving mail accounts around without inconveniencing the user. surely, if your user accounts are dealt with by NIS, and their home directories mounted via NFS, then it doesn't matter which of the cluster they connect to? Or is there a 32K+ limit on NIS user ids as well? ofcourse there is. NIS is just a way to manage your /etc/passwd centrally (no, don't start flaming now :) Greetz, Peter. -- .| Peter van Dijk | mo|VERWEG stoned worden of coden .| [EMAIL PROTECTED] | mo|VERWEG dat is de levensvraag | mo|VERWEG coden of stoned worden | mo|VERWEG stonend worden En coden | mo|VERWEG hmm | mo|VERWEG dan maar stoned worden en slashdot lezen:)
Re: 500.000+ users mailserver
At 20:13 +0100 03-03-99, [EMAIL PROTECTED] wrote: If you had a "server farm" with (say) 10 PCs, you don't have to worry about UID limits, even with versions of Unix that don't support 32-bit UIDs. You also don't have to worry about putting all of your users out of business if one server goes down, and chores like backups become much easier. Sun Solaris supports 32-bit uids. I don't know much about proxies; is there some nifty way for a user to connect to a large mail-server, have the server tell the user's machine "your mail is actually on server03", and then redirect the POP/SMTP requests to the correct PC without having all of the resulting traffic pass through one machine? This would allow you to load-balance by moving mail accounts around without inconveniencing the user. Yes, there is. There is a software package that can redirect users to different servers based on the database of your choice. It's called deligate if I'm not mistaken. (It can be used to redirect many protocols, such as POP, IMAP, HTTP, SMTP, etc.) You can achieve much of the same functionality by just using qmail. This has been discussed before on this list. One thing's for sure though, do not trust NFS-delivery in such a large enviroment. -frode-
Re: 500.000+ users mailserver
Or is there a 32K+ limit on NIS user ids as well? ofcourse there is. NIS is just a way to manage your /etc/passwd centrally (no, don't start flaming now :) Somewhere within the Sun NIS+ doco it talks about optimal sizes of around 10K objects. I've never been able to confirm what sort of degradation happens when you exceed that number by over an order of magnitude. I don't know whether this limitation applies to independent implementations (of which there is one I know of). The "large server" syndrome has been discussed on this list a number of times and the archives will show that you really only have two readily available solutions. One is to use one heck of a mother NFS server (a NetAPP or similar) and a fleet of front-end boxes that handle POP via layer 4 switching (eg Cisco Local Director or similar). The other is to allocate people on different physical servers - this is a lot cheaper, but suffers from failure modes and administrative pains. Regards.
