Re: [HACKERS] Resource management in 7.4
Personally I think that configuring things like that is definitely beyond the scope of an average administrator. However, there is one thing which would be useful for many applications: It would be nice if there was a way to renice a connection. When it comes to reporting it would be nice to have a handle for slowing a backend down. A patch for Linux would be quite easy (SELECT nice_backend(int)) but I don't know how this fits into the Windows port and PostgreSQL on other platforms. I think this would be a straight forward approach fixing most of the problems people might have with CPU usage. Is this the right way to go? Regards, Hans -- *Cybertec Geschwinde u Schoenig* Ludo-Hartmannplatz 1/14, A-1160 Vienna, Austria Tel: +43/1/913 68 09; +43/664/233 90 75 www.postgresql.at http://www.postgresql.at, cluster.postgresql.at http://cluster.postgresql.at, www.cybertec.at http://www.cybertec.at, kernel.cybertec.at http://kernel.cybertec.at ---(end of broadcast)--- TIP 3: if posting/reading through Usenet, please send an appropriate subscribe-nomail command to [EMAIL PROTECTED] so that your message can get through to the mailing list cleanly
Re: [HACKERS] Resource management in 7.4
Tom Lane [EMAIL PROTECTED] wrote: Gavin Sherry [EMAIL PROTECTED] writes: I've been thinking about resource management and postgres. I want to develop a user profile system (a-la oracle) which allows a DBA to restrict/configure access to system resources. This would allow a DBA to configure how much CPU time can be used per query/session for any user, the number blocks that can be read/written by a user per query, and perhaps some other things (see below). I've got really serious reservations about this whole idea. I don't like expending even one CPU cycle on it, and I don't like introducing a potential cause of unnecessary query failure, and I don't believe that the average DBA would be capable of configuring it intelligently. [snip] Another example is that the cost of verifying transaction completion is actually paid by the first transaction to visit a tuple after the tuple's authoring transaction completes. Should a transaction be penalized if it's foolish enough to do a seqscan shortly after someone else does a mass insert or update? Just want to give my $0.02. I believe the whole resource restriction idea is only interessting when different people share the same data e.g. several departments have access to a company-wide database for analysis purposes. In such a case it could be useful to restrict the resource usage of some users. On the other hand, in a shared hosting environment, I don't think anyone would really like to have resource limits. What does it help if your online shop stops working because too many people are ordering stuff? IMHO it would be much more useful to have resource usage accounting in that case, so that users can be charged for added database usage. That would probably also be easier to implement because each user would have their own database and only pg_xlog shared -- that part seems tricky as you said before. Best Regards, Michael Paesold ---(end of broadcast)--- TIP 6: Have you searched our list archives? http://archives.postgresql.org
Re: [HACKERS] Resource management in 7.4
On Sat, 21 Dec 2002, Sander Steffann wrote: Hi, On the other hand, in a shared hosting environment, I don't think anyone would really like to have resource limits. What does it help if your online shop stops working because too many people are ordering stuff? IMHO it would be much more useful to have resource usage accounting in that case, so that users can be charged for added database usage. I work for an ISP offering shared hosting, and I don't like the idea of resource limits at all. Probably two things will happen: - Applications/websites will break for no good reason - Customers will be complaining about how unreliable PostgreSQL is The system I would design would resemble that in Oracle. That is, by default a user has unlimited access to resources. If the admin chooses to limit resources, then so be it. The reason I've been thinking about it is some people I've been working with at universities have a problem with students effectively DoSing shared installations to affect assessment. This was something they had control over when they used Oracle :-(. Gavin ---(end of broadcast)--- TIP 6: Have you searched our list archives? http://archives.postgresql.org
Re: [HACKERS] Resource management in 7.4
On Sat, 21 Dec 2002, Tom Lane wrote: Gavin Sherry [EMAIL PROTECTED] writes: ... The reason I've been thinking about it is some people I've been working with at universities have a problem with students effectively DoSing shared installations to affect assessment. This was something they had control over when they used Oracle :-(. And the students have access to the administrative installation exactly why? Should have made this clearer. Students had a shared system to prepare assessments. Some students were DoSing Postgres so that other students could not finish assignments. Yes: the students should run their own installations, they should not need to have 100% uptime. But it didn't happen like that. It got me thinking... Gavin ---(end of broadcast)--- TIP 5: Have you checked our extensive FAQ? http://www.postgresql.org/users-lounge/docs/faq.html
