Re: Sessio variables and Load Balancing

From: Date: Fri, 30 Jun 2000 20:24:13 +0000
Subject: Re: Sessio variables and Load Balancing
References: 1 2 3 4  Groups: php.dev 
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> > How do we all know that NFS is unreliable under Linux? Why is it > > unreliable and were do I find documentation to support this? I've heard > > people say this, but never with any information to back that up.. seems > > more of a "feeling". > > Search around if you want to see reports of unreliability and performance > problems with NFS. There've been a couple Ask Slashdots about it, with the > general conclusion that recent kernels are much better than the old ones. > feeling? i doubt that, i've used NFS for linux, most people know that NFS is an invention is Sun, which is not as of this day open source, and does not have very good support in linux, read the NFS-howto and read yourself that NFS linux-client linux-server interactions are VERY slow and VERY upstable. 2.4.x should have much better support for this, and there is talk of Sun going opensource with NFS, but until either of those happen it would not be a very good idea to use NFS for thousands of sessions. > > It might be an *easier*solution to use the database to store sessions, but > > if you have thousands of visitors per day.. you will begin to drag your > > database server to the pits of hell with the number of queries you will be > > making just to retrieve session data, not counting the queries you would > > already be making to serve various dynamic content. Not recommended for a > > If you're using MySQL or a well-tuned Oracle install, this won't be a big > deal at all. Retrieving a record on an indexed column is extremely fast. If > the single query necessary to retrieve a session's data measurably affects > your site performance, your database is either severely underspeced or your > DBA should be fired for gross incompetence. > agreed, however if the programmer is writing to sessions 4-5 times per page that could have very detrimental effects on the database server. everyone needs to be informed whats going on and write things suitable for it.

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