Hello Andy, Thank you for your email. For the caching layer in addition to in-memory local cache option, I am considering to build provision to use couchbase or memcache as an option to use remote cache instances from Fuseki server.
Please let me know your feedback. Regards Saikat On Fri, Jan 9, 2015 at 7:08 PM, Andy Seaborne <[email protected]> wrote: > Hi Saikat, > > Comments inline > > On 08/01/15 12:27, Saikat Maitra wrote: > >> Hi Andy >> >> Thank you for your email and sharing the external cache implementation. It >> certainly helped me to understand some of the usecases better. >> >> I am thinking to implement the caching layer with a provision to use any >> of >> the options below. >> > > Good - I think the key is to get the right abstractions in the code with > different implementations. > > 1. We can use in-memory operation using Guava library and have regular >> schedule for execution of task to persist the data in disk. >> >> 2. The second option is to provide capabilities to use couchbase buckets >> to >> store the cache results and have a separate couchbase cluster instance. >> > > Realisically, for most deployments, in-memory is more important. > Especially as the cost-effective size of servers RAM these days seems to be > going up so quickly. > > I don't know enough about couchbase buckets -- which features do you see > as most relevant here? As a pratical matter - can they be used separately > from couchbase? > > I am still reading the Fuseki2 server code to understand the server work >> area. >> > > Andy > > > >> Regards >> Saikat >> >> >> >> On Thu, Jan 8, 2015 at 2:09 AM, Andy Seaborne <[email protected]> wrote: >> >> On 07/01/15 15:43, Saikat Maitra wrote: >>> >>> Hi >>>> >>>> I am Saikat, I am new to Apache Jena and I would like to contribute to >>>> SPARQL Query Caching (https://issues.apache.org/jira/browse/JENA-626). >>>> >>>> I would like to know if someone has already taken up the issue and >>>> currently working on it. I have reviewed the old messages in developers >>>> mail list and I suppose this issue is currently still Unassigned. >>>> >>>> Regards >>>> Saikat >>>> >>>> >>>> Hi Saikat, >>> >>> Good to check - no one seems have mentioned it any time recently. >>> >>> There is some code: >>> >>> https://svn.apache.org/repos/asf/jena/Experimental/sparql- >>> cache/README.markdown >>> >>> which is an external cache and has some issues: >>> >>> 1/ Updates don't invalidate the cache >>> >>> 2/ It's a rough prototype in scala I knocked together, not production >>> tested >>> >>> 3/ Claims of "rate control" are overstated (there isn't any). >>> (seems strange to have it in the cache code at all) >>> >>> In Fuseki2, there is a server work area on disk so putting results >>> somewhere on disk now makes more sense. Or memcached. >>> >>> Andy >>> >>> >>> >> >
