Hi, On Tue, Apr 10, 2018 at 08:38:32PM +0800, ??? wrote: > Hi, all, > haproxy still have the thundering herd problem in the multi-process > mode, the EPOLLEXCLUSIVE flag has been added since linux 4.5, which can > solve this problem
Well I disagree with this approach, it will instead degrade the situation. Let me explain. Right now when working in multi-process mode, it is strongly suggested to use multiple "bind" lines each with its own process. When this is done, the sockets are bound with SO_REUSEPORT, where the kernel performs some round-robin load balancing between all the sockets, and each process receiving connections will be woken up and will be able to accept at once *all* pending connections for its listener. With your approach what will happen is that a single process will be woken up for multiple pending requests at once, it will suck them all in a loop without leaving a chance to the other processes to take their share. This creates a huge imbalance that is already visible when using nbproc without the "process" directive on the bind lines. With SSL this has an even worse impact since a process can steal a lot of traffic and spend a lot of time in handshakes while the other ones are twidling thumbs. Regards, Willy
