At 03:33 PM 2/3/00 +1100, Peter Skipworth wrote:
>Does anyone have any experience in using IPC shared memory or similar in
>caching data amongst multiple httpd daemons ? We run a large-ish database
>dependent site, with a mysql daemon serving many hundreds of requests a
>minute. While we are currently caching SQL query results on a per-process
>basis, it would be nice to share this ability across the server as a
>whole.
>
>I've played with IPC::Shareable and IPC::ShareLite, but both seem to be a
>little unreliable - unsurprising as both modules are currently still under
>development. Our platform is a combination of FreeBSD and Solaris servers
>- speaking of which, has anyone taken this one step further again and
>cached SQL results amongst multiple web servers ?
We looked at this, as we have a busy multiple web server environment and
are planning to use Apache::Session + Mysql to manage session state.
Although per-host caching in shared memory or whatever seemed desirable on
paper, the complexities of ensuring that cache entries are not invalid due
to an update on another server are major.
When we set up a testbed to benchmark Mysql for this project, the
time taken to retrieve or update a session state record across the
network over an established connection to our Mysql host (Sparc 333 mhz
Ultra 5/Solaris 2.6 with lots of memory) was so small (5-7 ms including
LOCK/UNLOCK TABLE commands where needed) that we didn't pursue per host
caches any further.
Clearly, YMMV depending on the hardware you have available.
- Simon
>Thanks in advance,
>
>Peter Skipworth
>
>--
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>| Peter Skipworth Ph: 03 9897 1121 |
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Simon Rosenthal ([EMAIL PROTECTED])
Web Systems Architect
Northern Light Technology 222 Third Street, Cambridge MA 02142
Phone: (617)577-2796 : URL: http://www.northernlight.com
"Northern Light - Just what you've been searching for"
