Howdy, Thank you for the quick response. From what you said, I believe extstore is almost perfect for our usecase.
I had extensively read the wiki and I will read the blog posts now. Thanks again! Cheers, Jacob On Friday, December 4, 2020 at 2:30:18 PM UTC-5 thar...@gmail.com wrote: > For the extstore, it doesn't matter whether your data set is sharded or > not as the scope is a single Memcached process. Note that data is not > durable, if the Memcached process crashes, data can not be recovered. > > Yes, ext_item_age=0 will write data to the disk quickly, leaving only keys > + meta data in memory. It's using FS cache as it does > read/readv/pread/preadv. > > If the probability of reading an item is high after it's written, you can > increase the ext_item_age to keep it in memory. A possible downside of this > is if your write rate is high, memory is full and the disk writes are slow, > it will evict items before getting a chance to flush to the disk. > > Extstore will work with both write-once or with updates. > > More details are here: > https://github.com/memcached/memcached/wiki/Extstore#tuning-guide. The > original blog is here: https://memcached.org/blog/extstore-cloud/ > > On Friday, 4 December 2020 at 08:45:36 UTC-8 Jacob Eisinger wrote: > >> Oh, and, one more important aspect. Our data is mostly write-once, >> read-many times. There are no updates today. And, in the future, there >> will be very few updates. >> >> On Friday, December 4, 2020 at 11:05:18 AM UTC-5 Jacob Eisinger wrote: >> >>> >>> Howdy, >>> >>> We are investigating using Memcached's extstore as a >>> single/non-sharded/non-clustered application cache of data larger than >>> memory. From my reading, it sounds like this is not the typical use case. >>> Due to that, I wanted to see if there were any unintended consequences of >>> our configuration. >>> >>> Specifically, we are looking to configure extstore with ext_item_age=0. >>> From our initial testing, it looks like this means that this effectively >>> turns Memcached into a mostly disk-based cache of values. In particular, >>> Memcached will attempt to write out pages as soon as they fill to disk. >>> Then, when accessing values, the disk cache -> disk will be used. Is that >>> correct? >>> >>> We noticed the extstore file grows and the memcache memory stays >>> relatively low. If we wanted to keep more of the recent values in memory, >>> should we just increase the ext_item_age to a couple of hours? Are there >>> unintended consequences of this setup? Any other configuration that we >>> should be looking at? >>> >>> Cheers, >>> Jacob >>> >> -- --- 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. To view this discussion on the web visit https://groups.google.com/d/msgid/memcached/a5241775-44a1-4cb4-839a-48763efd86cfn%40googlegroups.com.
