K, in that case try using synchronized statements.
skeleton:
private Object lock = new Object();
static Queue<dataType> dataToInsert = new Queue<dataType>();
static long TIMEOUT = 30;
// thrift function
public bool insert(dataType data) {
long timeBegin = System.currentTimeMillis();
bool timedOut = false;
synchronized(lock) {
dataToInsert.add(data);
while (dataToInsert.size() <= INSERT_SIZE_THRESHOLD &&
((timedOut = ((System.currentTimeMillis() - timeBegin()) >
this.TIMEOUT)))) {
wait(this.TIMEOUT);
}
if (dataToInsert.size() > 0) {
// clear out dataToInsert and dump to DB HERE
notifyAll();
}
}
return (!timedOut && !someDBErrorOccurred) ;
}
--------------------------
Philip Fung
Engineering
Facebook, Inc.
[EMAIL PROTECTED]
On May 28, 2008, at 1:46 PM, Benjamin Reed wrote:
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
