Seems pretty overengineered, imo, given you can just save the pagination state as Andy Tolbert pointed out.
> On Oct 4, 2017, at 8:38 AM, Daniel Hölbling-Inzko > <daniel.hoelbling-in...@bitmovin.com> wrote: > > Thanks for pointing me to Elassandra. > Have you had any experience running this in production at scale? Not sure if > I > > I think ES will enter the picture at some point since some things just don't > work efficiently with Cassandra and so it's inevitable in the end. > But I'd rather delay that step for as long as possible since it would add a > lot of complexity and another layer of eventual consistency I'd rather not > deal with at the moment :) > > greetings Daniel > > On Wed, 4 Oct 2017 at 08:36 Greg Saylor <gr...@net-virtual.com > <mailto:gr...@net-virtual.com>> wrote: > Without knowing other details, of course, have you considered using something > like Elassandra? That is a pretty tightly integrated Cassandra + Elastic > Search solution. You’d insert data into Cassandra like you do normally, > then query it with Elastic Search. Of course this would increase the size of > your storage requirements. > > - Greg > > >> On Oct 3, 2017, at 11:10 PM, Daniel Hölbling-Inzko >> <daniel.hoelbling-in...@bitmovin.com >> <mailto:daniel.hoelbling-in...@bitmovin.com>> wrote: >> >> Thanks Kurt, >> I thought about that but one issue is that we are doing limit/offset not >> pages. So one customer can choose to page through the list in 10 Item >> increments, another might want to page through with 100 elements per page. >> So I can't have a clustering key that represents a page range. >> >> What I was thinking about doing was saving the paginationState in a separate >> table along with limit/offset info of the last query the paginationState >> originated from so I can use the last paginationState to continue the >> iteration from if the customer requests the next page with the same limit >> but a different offset. >> This breaks down if the customer does a cold offset=1000 request but that's >> something I can throw error messages for at, what I do need to support is a >> customer doing >> Request 1: offset=0 + limit=100 >> Request 2: offset=100 + limit=100 >> Request 3: offset=200 + limit=100 >> >> So next question would be: How long is the paginationState from the driver >> current? I was thinking about inserting the paginationState with a TTL into >> another Cassandra table - not sure if that's smart though. >> >> greetings Daniel >> >> On Tue, 3 Oct 2017 at 12:20 kurt greaves <k...@instaclustr.com >> <mailto:k...@instaclustr.com>> wrote: >> I get the impression that you are paging through a single partition in >> Cassandra? If so you should probably use bounds on clustering keys to get >> your "next page". You could use LIMIT as well here but it's mostly >> unnecessary. Probably just use the pagesize that you intend for the API. >> >> Yes you'll need a table for each sort order, which ties into how you would >> use clustering keys for LIMIT/OFFSET. Essentially just do range slices on >> the clustering keys for each table to get your "pages". >> >> Also I'm assuming there's a lot of data per partition if in-mem sorting >> isn't an option, if this is true you will want to be wary of creating large >> partitions and reading them all at once. Although this depends on your data >> model and compaction strategy choices. >> >> On 3 October 2017 at 08:36, Daniel Hölbling-Inzko >> <daniel.hoelbling-in...@bitmovin.com >> <mailto:daniel.hoelbling-in...@bitmovin.com>> wrote: >> Hi, >> I am currently working on migrating a service that so far was MySQL based to >> Cassandra. >> Everything seems to work fine so far, but a few things in the old services >> API Spec is posing some interesting data modeling challenges: >> >> The old service was doing Limit/Offset pagination which is obviously >> something Cassandra can't really do. I understand how paginationState works >> - but so far I haven't figured out a good way to make Limit/Offset work on >> top of paginationState (as I need to be 100% backwards compatible). >> The only ways which I could think of to make Limit/Offset work would create >> scalability issues down the road. >> >> The old service allowed sorting by any field. If I understood correctly that >> would require a table for each sort order right? (In-Mem sorting is not an >> option unfortunately) >> In doing so, how can I make the Java Datastax mapper save to another table >> (I really don't want to be writing a Subclass of the Entity for each Table >> to add the @Table annotation. >> >> greetings Daniel >> >
