If you must free up the thread, I think you could use continuations. I haven't tried it but there seems to be a library for java continuations (http://rifers.org/downloads/#rifecontinuations). You would have to save the continuation somewhere and then resume it once the batch job is done. This is pretty much equivalent to putting the thread to sleep until the job is done though.
-----Original Message----- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On Behalf Of Benjamin Reed Sent: Wednesday, May 28, 2008 1:47 PM To: Philip Fung Cc: [email protected]; [EMAIL PROTECTED] Subject: Re: [thrift] RPC with completion functions Yes, I really need a success code. (The client is going to be waiting for it.) I want to do exactly what you are proposing except that I want to queue a completion function into dataToInsert as well, so that the insertWorker can send back the response to the rpc to the client when the commit completes. thanx ben On Wednesday 28 May 2008 12:01:49 Philip Fung wrote: > Does your calling function really need to know if the insert was > successful? If you can do without this extra overhead, then I think > the best way to do this is to place the insert request on a queue and > free up the RPC request immediately rather than wait for the inserts > to batch up and complete. > > So some skeleton code would be: > > static LinkedBlockingQueue<dataType> dataToInsert = new > LinkedBlockingQueue<dataType>(); //java.util.concurrent > static int INSERT_TIME_THRESHOLD = 3600; > static int INSERT_SIZE_THRESHOLD = 1000; > > // thrift-accessible function > public void insert(dataType data) { > this.dataToInsert.add(data); //thread-safe > } > > // worker threads > private static class insertWorker extends Thread { > > public void run() { > > ArrayList<dataType> dataToInsertWorker = new > ArrayList<dataType>(); > while (true) { > > dataToInsertWorker.add(this.dataToInsert.take()); //blocks > > if ((dataToInsertWorker.size() > INSERT_SIZE_THRESHOLD) || > (dataToInsertWorker.size() > 1 && > (System.currentTimeMillis() - > lastInsertTime) > INSERT_TIME_THRESHOLD)) { > > // insert into DB here > > lastInsertTime = > System.currentTimeMillis(); > } > } > > } > } > > > > > -------------------------- > Philip Fung > Engineering > Facebook, Inc. > [EMAIL PROTECTED] > > On May 28, 2008, at 11:46 AM, Ben Maurer wrote: > > Hey, > > > > Usually, when writing stuff for thrift, I've found it's best to > > create an > > object that takes parameters: > > > > FooReturn doFoo(1: FooArgs args); > > > > For the return value, this is pretty critical because thrift doesn't > > allow > > you to return multiple values. For the arguments, I've found that even > > though thrift can support multiple arguments, doing this makes it > > easier > > (eg, you can serialize args and log it). > > > > So for this kind of API I'd just take the args value insert it into a > > queue. It does require a bit of work for each function, however, you > > can > > also do stuff like validate the request and raise an exception if > > you know > > the insert will fail. > > > > -b > > > > On Wed, 28 May 2008, Benjamin Reed wrote: > >> Could I get a pointer to how to deal with the following scenario: > >> > >> I have a Java server using thrift. There are potentially hundreds > >> of clients > >> sending hundreds of requests at a time. The server receives a > >> request, > >> batches it up with other pending requests, processes a batch at a > >> time, and > >> then generates the responses when the batch finishes. > >> > >> For example, clients A, B, and C, are each sending up records to be > >> inserted > >> into a database. The clients are sending up 1000 requests per > >> second. The > >> server will grab some number, lets say 100 requests at a time, > >> insert them > >> into the database, issue a commit, and send back successful > >> responses. Doing > >> batch commits of 100 requests at a time allows the server to keep > >> up with the > >> clients. Committing each request individually would be too slow. > >> > >> So, in my Java server, how do I get an RPC request and then put it > >> on a > >> completion list so that I can free up the thread for the next RPC > >> call and > >> complete the RPC when I do the batch processing? > >> > >> thanx > >> ben > >> _______________________________________________ > >> thrift mailing list > >> [EMAIL PROTECTED] > >> http://publists.facebook.com/mailman/listinfo/thrift > > > > _______________________________________________ > > thrift mailing list > > [EMAIL PROTECTED] > > http://publists.facebook.com/mailman/listinfo/thrift _______________________________________________ thrift mailing list [EMAIL PROTECTED] http://publists.facebook.com/mailman/listinfo/thrift
