Solved

What's the recommended max # of open files in my situation?

Posted on 2004-04-20
5
333 Views
Last Modified: 2013-12-16
I run a very busy web server with 4000+ domains of which about 10% of them are very active. The tech specs:

1. RH 7.1 + Apache 1.3
2. Dual 1 GHz PIII
3. 4 GB ECC RAM
4. Dual 74 GB SCSI

May I know what's the recommended max # of open files (file-max) in MY SITUATION? In addition, should I increase the max # of open inodes (inode-max)? Please point me to the reference you used to formulate your conclusion. Please don't preach about Apache tuning or anything off topic. Thank you.



0
Comment
Question by:topwiz
[X]
Welcome to Experts Exchange

Add your voice to the tech community where 5M+ people just like you are talking about what matters.

  • Help others & share knowledge
  • Earn cash & points
  • Learn & ask questions
5 Comments
 
LVL 40

Expert Comment

by:jlevie
ID: 10872324
The "recommended max # of open files" is whatever is necessary for your server to operate without encountering application failures as a result of too many open files. If you aren't having problem in that respect now the current number is adequate.

Fiddling with the file-max or inode-max isn't something you do to improve performance. However, gratuitiously increasing those values far above what the server really needs can negatively affect performance by increasing the amount of memory allocated for the data structures to kernel needs.
0
 
LVL 9

Expert Comment

by:Alf666
ID: 10872793
For the inodes part, I suggest using another filesystem like reiserfs in which you don't have to bother about inode limits.
Though you should be carefull. No directory with too many files.
0
 
LVL 15

Accepted Solution

by:
DonConsolio earned 500 total points
ID: 10944804
for our servers i wrote a perl script to periodically check open files and stuff and send reports in case of error.

basically i do this:

...
open PSTAT, '/proc/sys/fs/file-nr' or warn $!;
my ($filealloc,$filenr,$filemax) = split(/\s+/,<PSTAT>);
close PSTAT;
                                                                                               
my $PCTFULL = int($filenr * 100 / $filemax);

...
if PCTFULL reaches 95% i send mail to the admin mailbox and have it increased in the init scripts as soon as possible.

0
 
LVL 22

Expert Comment

by:pjedmond
ID: 11766082
Just a thought, but I suspect that the spec that you have given us will not be the bottleneck. The bottleneck on this setup will mostlinkely be the ethernet connection. This will apply if the majority of files being accessed are over about 5-10K.

The next area that I would expect the bottleneck to be if you upgrade your ethernet card to a 1000/100/10 card would be the SCSI.

Issues here depend on spindle, and hence access/latency timings for the hard drive. Also the RAID array (if used) could vastly increase access speed, especially if you have a fairly high performance setup with a caching RAID array.

Therefore, the first thing that I'd be monitoring would be the ethernet bandwidth usage. If it gets above about 30% of the rated bandwith...i.e. 30Mb for a 100Mb link, then I would start to get concerned. Above that, the number of collisions start to cause problems with service. However, I expect, that the banwith that connects this server to the internet might be more limiting than that?

HTH:)
0
 
LVL 22

Expert Comment

by:pjedmond
ID: 11766116
Now you know where to look for the first singn of any problems:).....use ratios to multiply bandwidth up to 30% of that available, and I'd guess that would match up proportionally to a number of the other factors that you've mentioned monitoring tools for. Use that as the threshold for you to start thinking about taking action:)
0

Featured Post

Free Tool: IP Lookup

Get more info about an IP address or domain name, such as organization, abuse contacts and geolocation.

One of a set of tools we are providing to everyone as a way of saying thank you for being a part of the community.

Question has a verified solution.

If you are experiencing a similar issue, please ask a related question

Introduction We as admins face situation where we need to redirect websites to another. This may be required as a part of an upgrade keeping the old URL but website should be served from new URL. This document would brief you on different ways ca…
Google Drive is extremely cheap offsite storage, and it's even possible to get extra storage for free for two years.  You can use the free account 15GB, and if you have an Android device..when you install Google Drive for the first time it will give…
Learn several ways to interact with files and get file information from the bash shell. ls lists the contents of a directory: Using the -a flag displays hidden files: Using the -l flag formats the output in a long list: The file command gives us mor…
This demo shows you how to set up the containerized NetScaler CPX with NetScaler Management and Analytics System in a non-routable Mesos/Marathon environment for use with Micro-Services applications.

717 members asked questions and received personalized solutions in the past 7 days.

Join the community of 500,000 technology professionals and ask your questions.

Join & Ask a Question