On 8/22/07, Jeroen Brattinga <[EMAIL PROTECTED]> wrote:
> Well, I just use the (Mina) ByteBuffer (see
> http://mina.apache.org/report/1.1/apidocs/org/apache/mina/common/ByteBuffer.html)
> methods to get each field (e.g. getUnsignedInt, getString, getChar). I
> have one class that does the basic unpacking (header, CRC, payload size
> etc.), and some more specific classes that worry about the payload. I didn't
> find it cumbersome, although a struct would have been easier.
>
> But now that it's implemented, I only deal with nice and easy message
> objects that contain the processed data (using the
> DemuxingProtocolCodecFactory).
>
> Could you give a more detailed specification of one of your packets? It
> would give us some more insight into the problem.
>
Thanks. Jeroen
My protocol is something like:
byte(type of message) + byte(length of body-little-endian) + head + body
head:
#define Length 450
typedef struct _tagHeader
{
char cServiceName[6];
char cCompress[1];
char cComprLevel[1];
unsigned int A;
unsigned int B;
...
}Header
body:
typedef struct _tagBody
{
unsigned int iLength;
char cMsg[MaxBodyLength];
}Body;
What bothered me is:
1) convert each integer field from little-endian to big-endian
2) use system.arraycopy in order to get each byte array and convert a byte
array to string
It takes really a lot of CPU time and memory for decode and encode.
> Jeroen Brattinga
>
>
> mat wrote:
>
> The reason why I raised this thread is: recently I am really bothered with
> following issue.
>
> My mina component has to connect to a legacy server written in C++. C++
> server just simply sends out the struct as a message. I think for a C++
> program it is just simple return the struct pointer and use each field.
> However, to my java program that is a disaster(also really lower the
> performance). I have to use all the system.arraycopy to make up each
> field.(Actually it causes OOM). I don't know if you guys ever faced this
> kind of problem. How to solve it?
>
>
> On 8/11/07, Emmanuel Lecharny <[EMAIL PROTECTED]> <[EMAIL PROTECTED]> wrote:
>
>
> Hi guys,
>
> when guessing relative performances of Java/C++ on a network
> environment, please keep in mind that data processing will be
> processed orders or magnitude faster than simple network handling by
> the underlying layer. Thinking that Java is slower than C++ to handle
> messages on a network based application because it does not have
> pointers is out of base.
>
> FYI, I have tested our LDAP server on my laptop, sending Search
> requests through MINA (Apache Directory Server is based on MINA, 1.0.3
> version), and I got something like 5000 req/s (a request is around
> 1kb), assuming that almost all the time is spent internally to the
> server itself, not in the MINA layer. Btw, LDAP messages are binary,
> but that does not mean it's easier to decode them in C/C++ than in
> Java (I would say that the complexity is exactly the same for both
> languages).
>
> I don't want to start a flame war, but I encourage anyone who want to
> compare Java and C++ to compare things that are comparable, and not
> blind guess what can be slow or fast in both languages.
>
> My 2cts
> Emmanuel
>
> On 8/11/07, mat <[EMAIL PROTECTED]> <[EMAIL PROTECTED]> wrote:
>
>
> Actually the windows IOCP server is written in C++ and it is running on
>
>
> a pc
>
>
> server. I believe the reasons why Java can't reach that performance
> sometimes due to lack of structure(pointer). I find it is really
>
>
> cumbersome
>
>
> job to decode a binary message in Java. I don't know if you guys have
>
>
> better
>
>
> solution to decode the binary format and manipulate the each field in
>
>
> the
>
>
> binary message.
>
> On 8/11/07, Michael Grundvig <[EMAIL PROTECTED]> <[EMAIL PROTECTED]> wrote:
>
>
> I don't have the exact numbers but I know on a big Linux box (8
> processors,
> 8 gb ram) with a switched gigabit backbone we have seen greater then
> 45,000 - 50,000 messages per second sustained. Ultimately the problem
> becomes a matter of garbage collector churn rather then IO overhead.
>
>
> On
>
>
> Windows machines we could get only to a fraction of that. We believe
>
>
> the
>
>
> underlying I/O differences between Windows and *nix become really
>
>
> obvious
>
>
> when you get to higher message counts.
>
> Michael
>
> ----- Original Message -----
> From: "mat" <[EMAIL PROTECTED]> <[EMAIL PROTECTED]>
> To: "dev" <[email protected]> <[email protected]>
> Sent: Friday, August 10, 2007 11:24 AM
> Subject: Mina throughput
>
>
>
>
> Does anyone have the throughput test by raw socket communication
> (keep-alive
> mode)? My colleague wrote a windows IOCP server whose throughput
>
>
> could
>
>
> reach1.8m/sec. (5000message/sec in intranet).
>
>
>
> --
> Regards,
> Cordialement,
> Emmanuel Lécharnywww.iktek.com
>
>
