Re: [gentoo-server] Apache with SSL scaling

[Josh Wyatt]

Sven Vermeulen wrote:
> Hi all,
>
> We're trying to deploy an environment on a two 1.5Ghz PIV with 4Gb of
> memory. However, we're noticing that we quickly reach a maximum load for
> SSL-requests on the webserver alone.
>
> We maxed out on around 1800 active HTTPS sessions who generated around 130
> requests (GET/POST) per second. Is this to be expected for this
> configuration? A higher load drops connections (the SSL cache can't handle
> more load), our number of Apache clients/threads scales well - we have an
> average of 320 threads (13 processes, each 25 threads) at any point of
> time.
>
> We are using the plain Apache (2.0) with the built-in SSL support.
>
> Wkr,
>     Sven Vermeulen

At high load, are you experiencing high load average?  Are you seeing high I/O on the partition with Apache?

Although you mentioned SSL cache, you didn't mention the value of SSLSessionCache in your config.

You will find that with high-concurrency hosting, 'dbm' or 'none' won't cut it - switch to shm instead, and give it some healthy space:
SSLSessionCache shm:/path/to/session/file(2048000)

Also consider disabling logging to minimize I/O.

Thanks,
Josh

-- 
gentoo-server@g.o mailing list