There's nothing like what you're asking about built into memcached (i.e. key rebalancing). You can use a proxy like mcrouter to create a new pool of servers and then migrate your data by copying it over whenever a key is looked up (look up WarmUpRoute). You won't necessarily have confidence that all of the keys have been moved unless you know that they have all been accessed during your warmup period. If your constraints for data loss are too high for this to be viable, you might want to consider a data store with persistence built in.
On Sat, Feb 17, 2018 at 10:59 PM, praveen kumar <[email protected]> wrote: > I am just curious to know how the below situation is handled at > architecture level of Memcached: > > Assume we have configured 4 server to hold our key-value pairs that are > cached and we have dedicated equal amount of memory for this purpose, say > 1GB per server. > During the course of our dynamic web page we cached many results into our > memcache system by following good hashing function that is likely to > distribute all the keys to all the server. At a given point in time, lets > assume we have .5GB of data cached in each of the four server. For some > reason, say we want to remove the fourth server from the system but still > want to retain the key-value pairs stored in it to be accessible at high > speed? How do we re-distribute it among other 3 servers (which still has > 0.5GB of storage each)? > > I am new to memcached. Please let me know if my thinking in terms of > system architecture, or scenario is incorrect... > > Will be waiting for the feedback from the mailing list :) > > -- > > --- > 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/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 [email protected]. For more options, visit https://groups.google.com/d/optout.
