+1. On Mon, 27 Jun 2016, 'Jay Grizzard' via memcached wrote:
> This is really heavily dependent on the exact hashing algorithm your library. > Some are (relatively) good about losing a server, others are complete trash > about it. I don’t > know what the perl lib does off the top of my head. > I’m assuming new-memcache01 is the mcrouter box? If so, you might consider > listing it multiple times (assuming the lib doesn’t try to prevent that). > > e.g. at first, do: > > memcache_servers => ['new-memcache01','memcache02', 'memcache03', > 'memcache04’] > > …and then… > > memcache_servers => ['new-memcache01’,’new-memcache01', 'memcache03', > 'memcache04’] > > …and then once all four (or howevermany) servers all all new-memcache01, you > can just collapse it to [ ‘new-memcache01’ ] and call it done. The keys are > all the same > regardless of where they hash to, so this will let you get away from the old > servers without worrying about your keys getting rehashed strangely and > completely destroying your > hit rate. > > -j > > On Mon, Jun 27, 2016 at 2:53 PM, Geoff Galitz <ggal...@shutterstock.com> > wrote: > Hi... > We're working on a project to migrate from one set of memcache servers to > newer largers ones which are behind a mcrouter. > > One option on the table is to take the current memcache_servers array in our > perl app and replace a single instance with the larger new memcache > server/cluster. Once > the new larger server(s) is warmed up we'd start popping servers off the end > of the array to shrink it. Would this a problem? My concern is that the > index would become > invalid and we'd invalidate the entire memcache pool. > > As an example: > > Starting config: > memcache_servers => ['memcache01', 'memcache02', 'memcache03', 'memcache04'] > > Next: > memcache_servers => ['new-memcache01','memcache02', 'memcache03', > 'memcache04'] > > Next: > memcache_servers => ['new-memcache01','memcache02', 'memcache03'] > > and so on. > > Any thoughts? > > > -- > > --- > 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 memcached+unsubscr...@googlegroups.com. > For more options, visit https://groups.google.com/d/optout. > > > -- > > --- > 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 memcached+unsubscr...@googlegroups.com. > For more options, visit https://groups.google.com/d/optout. > > -- --- 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 memcached+unsubscr...@googlegroups.com. For more options, visit https://groups.google.com/d/optout.
