Alex Karasulu wrote:
Hi Johan,
On Tue, May 27, 2008 at 3:47 PM, Johan Haleby <[EMAIL PROTECTED]> wrote:
Hi,
I'm using Apache Mina to parse continuous XML streams. I.e. a client
connects to Mina and holds a connection for its entire life-cycle. During
this time the client may send and receive a lot of (small) XML messages. I
wonder how I should implement this is in a good way? Right now my protocol
decoder is a singleton that make use of cached thread pool because each
client creates a new custom made inputstream implementation that is read in
a separate thread by XStream. When new data arrives to the decode method it
just pushes this data to the inputstream. The inputstream itself uses a
blocking queue, so the read method waits until it has data or that an "end
of stream marker" has been found, e.g. until </request> has been found.
I presume the read from the InputStream is using threads from this shared
thread pool? This is a tough problem to deal with when you have some
blocking IO primitives between MINA and your application.
First of all thanks for your reply, and yes the inputstream is of course
using threads from the shared thread-pool.
Although not optimal, I would use a decoder per session and start collecting
a request buffer in the MINA session until you detect the completion of a
request. This way there is minimal processing except for request
termination detection. Also you don't have to have this thread cache (pool)
to contend with in a singleton. When you detect the arrival of a complete
request you can trigger XStream deserialization of the buffer to produce the
object and forward the object up to higher layers.
HTH,
Alex
This is exactly what I was thinking as an alternative. And since the XML
messages are small I don't really need to worry too much about the cost
of double data holding which will occur in this case. I just have one
follow-up question, how do you configure Mina to use one ProtocolDecoder
instance per session?
/Johan
