Yes. OS doesn't pre-allocate the full buffer.
Yes. Memcached should easily handle million concurrent idle connections (given enough memory). Except, if user has only allocated 512MB/1GB RAM for TCP, it is "possible" at runtime only four connections have eaten up all the memory, which could lead to connection refused or some other errors. Lets revisit the question. Is memcached unable to handle large no of concurrent connection? Usually no. Under some circumstances. Yes. And yes, don't guess. Just try it. Open <server_tcp_mem/256MB> connections with large multi-get request (response > 256MB) and don't read them at client side. And then try opening more connections. thanks! rohitk On Sun, Jul 28, 2013 at 11:04 PM, dormando <[email protected]> wrote: > No. > > That does not pre-allocate the full buffer. Otherwise memcached servers > wouldn't be able to hold more than 100-200 connections open at once. I've > seen servers run 80,000+ just fine. > > Don't guess. > > On Sun, 28 Jul 2013, Rohit Karlupia wrote: > > > It might have something to do with MAX_SENDBUF_SIZE in memcached.h > Memcached tries to set this value to about 256 MB per socket and if that > > succeeds, it obviously limits the number of concurrent connections you > can have. On the other side, it helps in processing large multi-get > > requests. I am sure if you decrease this value, memcached would not have > much problem handling large concurrent connections, except multi-gets will > > become slightly slower. > > > > thanks, > > rohitk > > > > > > > > > > On Fri, Jul 26, 2013 at 11:31 AM, Ryan Chan <[email protected]> > wrote: > > Actually have been using memcached for years and didn't have any > problem, but find a new memcached proxy called "twemproxy" and it > > said: > > > > - Maintains persistent server connections. > > - Keeps connection count on the backend caching servers low. > > > > Actually what wrong with memcached on the above two points? > > Anyone have experience to share? > > > > Thanks. > > > > -- > > > > --- > > You received this message because you are subscribed to the Google > Groups "memcached" group. > > To unsubscribe from this group and stop receiving emails from it, send > an email to [email protected]. > > For more options, visit https://groups.google.com/groups/opt_out. > > > > > > > > > > -- > > > > --- > > You received this message because you are subscribed to the Google > Groups "memcached" group. > > To unsubscribe from this group and stop receiving emails from it, send > an email to [email protected]. > > For more options, visit https://groups.google.com/groups/opt_out. > > > > > > > > > > -- > > --- > You received this message because you are subscribed to the Google Groups > "memcached" group. > To unsubscribe from this group and stop receiving emails from it, send an > email to [email protected]. > For more options, visit https://groups.google.com/groups/opt_out. > > > -- --- You received this message because you are subscribed to the Google Groups "memcached" group. To unsubscribe from this group and stop receiving emails from it, send an email to [email protected]. For more options, visit https://groups.google.com/groups/opt_out.
