On Jul 18, 2019, at 4:21 AM, Winfield, Alister via Freeradius-Users <freeradius-users@lists.freeradius.org> wrote:
If what you are really seeing is short bursts of high rates and the server can easily keep up feel free to make the buffer HUGE. Latency might go up when the burst arrives but assuming it's all processed before timeouts start occurring you are good. If you are really starved for resource then increasing the buffers is bad news and might mean you process nothing before timeout essentially creating a total service failure rather than handling some percentage of requests. (This is especially true for DHCP, so much so that random drops to keep the queue short actually works better than answering everything when overloaded).
Agreed. As a side note, we're using v4 for DHCP with Redis Cluster. An *out of the box* configuration gets 8K DHCP DORAs per second. With a bit of tuning and more CPU, we're getting higher rates than that. The new ISC DHCP server gets less than that with its *in-memory* database! When SQL is used, ISC is getting ~500/s, where we're getting sustained 2K+ to PostgreSQL. I'm not aware of any other DHCP server with this level of performance. :) Alan DeKok.