Also, there is another issue: 1 million users could be a lot to lose, and a few files aren't as resilient as a DB, which gives you things like replication and redundancy.
Since you stated that only a few users will connect at a time, then sure, performance isn't an issue. Maintainability, like Shachar stated is definitely an issue at that scale. I just wanted to add that data reliability is a factor when dealing with such a large data set (even just using the 'passwd' command can bork a shadow file on occasion). Anyhow - interesting question! Tom On Wed, Jun 29, 2011 at 2:02 PM, Nadav Har'El <n...@math.technion.ac.il>wrote: > On Wed, Jun 29, 2011, Shachar Shemesh wrote about "Re: practical limit on > the number of UIDs": > > When you reach so many users, the problems relating to questions such as > > "how long does it take nss to parse /etc/passwd" start to be dwarfed by > > the human cost of maintaining a megaline text file. If for that reason > > alone, you will need to switch to a DB back end. > > I don't know what scenario Muli had in mind, but I can imagine one: > > There's a generation-old debate on whether the file system is enough for > keeping data, big or small, (this is clearly "the Unix way") or whether > things like separate database software are needed. > > Now, imagine that you are hosting, say, a blog site with a million users, > and > are one of the big believers of the capabilities of the Unix filesystem. > Certainly, you say to yourself, you can keep each blog post as a separate > file and you don't need a database. But to help maintain fool-proof > security, > you'd want each of the site's users to have his own uid, and his blog posts > are writable only to him, so that other users couldn't edit his posts even > if there was a bug in your web UI. So, can this be done - can you have a > million different UIDs? > > I'd guess there should be no reason why not - the kernel nevers sees a list > of uids anyway (as far as I know), and just sees a 32-bit integer uid. > By the way, if you don't intend these users to use the "ordinary" login > programs (like ssh), there's no reason to actually list them in > /etc/passwd: > Nothing prevents you from working with numeric user ids, and if you want > to convert your site's login names into numeric user ids, you'd most likely > use some sort of hash table - or even a file system directory ;-) - and not > a stupid linear file like /etc/passwd. > > -- > Nadav Har'El | Wednesday, Jun 29 2011, 27 Sivan > 5771 > n...@math.technion.ac.il > |----------------------------------------- > Phone +972-523-790466, ICQ 13349191 |Always remember you're unique, just > like > http://nadav.harel.org.il |everyone else. > > _______________________________________________ > Linux-il mailing list > Linux-il@cs.huji.ac.il > http://mailman.cs.huji.ac.il/mailman/listinfo/linux-il >
_______________________________________________ Linux-il mailing list Linux-il@cs.huji.ac.il http://mailman.cs.huji.ac.il/mailman/listinfo/linux-il
