Have you had a chance to try this technique out in Java ? I've not been able to get back to my original experiments for the last week.
If it works you should be able to put together a non blocking client that still used thrift. Aaron On 30 Jul 2010, at 16:57, Ryan Daum wrote: > An asynchronous thrift client in Java would be something that we could really > use; I'm trying to get a sense of whether this async client is usable with > Cassandra at this point -- given that Cassandra typically bundles a specific > older Thrift version, would the technique described here work at all with a > 0.6.x or 0.7 distribution? Has anybody tried this? > > Barring this we (place where I work, Chango) will probably eventually fork > Cassandra to have a RESTful interface and use the Jetty async HTTP client to > connect to it. It's just ridiculous for us to have threads and associated > resources tied up on I/O-blocked operations. > > R > > On Tue, Jul 27, 2010 at 11:51 AM, Dave Viner <davevi...@pobox.com> wrote: > FWIW - I think this is actually more of a question about Thrift than about > Cassandra. If I understand you correctly, you're looking for a async client. > Cassandra "lives" on the other side of the thrift service. So, you need a > client that can speak Thrift asynchronously. > > You might check out the new async Thrift client in Java for inspiration: > > http://blog.rapleaf.com/dev/2010/06/23/fully-async-thrift-client-in-java/ > > Or, even better, port the Thrift async client to work for python and other > languages. > > Dave Viner > > > On Tue, Jul 27, 2010 at 8:44 AM, Peter Schuller <peter.schul...@infidyne.com> > wrote: > > The idea is rather than calling a cassandra client function like > > get_slice(), call the send_get_slice() then have a non blocking wait on the > > socket thrift is using, then call recv_get_slice(). > > (disclaimer: I've never used tornado) > > Without looking at the generated thrift code, this sounds dangerous. > What happens if send_get_slice() blocks? What happens if > recv_get_slice() has to block because you didn't happen to receive the > response in one packet? > > Normally you're either doing blocking code or callback oriented > reactive code. It sounds like you're trying to use blocking calls in a > non-blocking context under the assumption that readable data on the > socket means the entire response is readable, and that the socket > being writable means that the entire request can be written without > blocking. This might seems to work and you may not block, or block > only briefly. Until, for example, a TCP connection stalls and your > entire event loop hangs due to a blocking read. > > Apologies if I'm misunderstanding what you're trying to do. > > -- > / Peter Schuller > >
