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 >> > >
