Tuning upstream keepalive parameter
mdounin at mdounin.ru
Thu Nov 5 13:19:09 UTC 2015
On Thu, Nov 05, 2015 at 12:55:36AM -0500, CJ Ess wrote:
> So I'm looking for some advice on determining an appropriate number for the
> keepalive parameter within an upstream stanza.
> They server processes ~3000 requests per second, and haproxy is the single
> upstream destination. Dividing by the request rate by the number of
> processors (workers) I'm thinking that maybe 256 is a good starting number
> for the max keepalives.
> Is that realistic? Or should I be looking at a fraction of that number?
Number of requests per second processed is mostly irrelevant. Two
important numbers are:
- How many connections your upstream servers can handle. It's a good
idea to don't exhaust all available connections with keepalive
- How many connections are used under normal load and/or during
load spikes. That is, how many simultaneous requests are
executed on upstream servers. It make sense to keep comparable
number of connections alive to handle load fluctuations.
More information about the nginx