Performance tips for heavily loaded servers

[Rob Naccarato]

> Nathan Neulinger wrote:
> 
> > I have a server that routinely has 45-90 connections and just runs really
> > poorly. We've thrown more memory at it w/ some benefit, but not
> > significant.
> 
> We serve ~350-500 clients with userdata and applications from a single server
> (Sun E4000, 4 nics, 4 scsi cards).
> 

For the record: 330 Win95 clients being served from 2 DEC 2100A's and 1
DEC 1000A (applications only)..

> The biggest bottlenecks usually are disks and memory.
> 

This is definiately the *not* the case at my site.  CPU appears to be the
biggest problem.  Memory gets chewed, but never gets exhausted.  Discs are
fairly idle as the UBC (Unified Buffer Cache) that the OS provides get
upwards of 95% hits.

> At compile time put in -DUSE_MMAP if you can spare some extra memory.
> This gave a boost of ~40% for us.
> 

Done this.

Any other tips, especially for serving applications?


Rob Naccarato           "Civilized men are more discourteous than savages
Sys Admin               because they know they can be impolite without
Sheridan College        having their skulls split, as a general thing."
Oakville, Ont. Canada                      - Robert E. Howard