Hello, So here's patch, which includes all functionalities I think about. It propagates the response for every tracking server without changing it and without intercepting it. In my opinion we should propagate relative and absolute weights, because if you use weight=0 server's to offload checks then you can send relative weight change and 0 will stay where it is.
Regards, Michał 2017-01-20 10:54 GMT+01:00 Willy Tarreau <w...@1wt.eu>: > Hi Michal, > > On Thu, Jan 19, 2017 at 11:45:57PM +0100, Micha?? wrote: > > Hello, > > > > We use track's in haproxy to minimize check traffic in some situations > and > > after my last patch we are probably going to switch to agent-checks for > > live management of weights and statuses. One problem I see now - track > > don't propagate weight setting to trackers, so if we set agent-check on > > track we can manage status only. > > > > My first PoC solution works good, so I thought about introducing > something > > like agent-track or track-agent directive set on backends (or maybe it > > should be default, non-configurable behaviour) to propagate agent-check > > responses from main check to all tracking backends. Both default > behaviour > > and directive approach are small changes in code, but a little bigger in > > functionality. > > > > In my opinion if we set agent-check on backend which is tracked by > others - > > it should propagate agent-check weight response to those tracking backend > > and set weight on them too. Configurable or not - it will be good > feature. > > I think we at least propagate the DRAIN state which is equivalent to > weight == 0. If so I too think we should propagate *relative* weights. > Agent-checks can return a relative weight (eg: 50%, 100%, 150%) or an > absolute weight (eg: 10, 20). If you have two farms configured like this : > > backend farm1 > server new1 1.1.1.1:8000 weight 10 agent-check > server new2 1.1.1.2:8000 weight 10 agent-check > > backend farm2 > server new1 1.1.1.1:8000 weight 20 track farm1/new1 > server new2 1.1.1.2:8000 weight 20 track farm1/new2 > server old1 1.1.1.3:8000 weight 10 check > server old2 1.1.1.4:8000 weight 10 check > > Then you want the weight changes on farm1 to be applied proportionally > to farm2 (ie: a ratio of the configured absolute weight, which is iweight > IIRC). > > Otherwise that sounds quite reasonable to me given that the agent-check's > purpose is to provide a more accurate vision of the server's health, and > that tracking is made to share the same vision across multiple farms. > > Regards, > Willy >
0001-MINOR-checks-propagate-agent-check-weight-to-tracker.patch
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