Hi Joe,
I saw that max message size is set to 128k from branch rev. 863.
But, I think that BlockingIOMulticastSender.java's DEFAULT_MULTICAST_PACKET_SIZE(16k bytes) should also be increased.
For example,
Now user can broadcast a large multicast packet(over 16k) to the group by GroupHandle#sendMessage(), then the packet won't be able to be parsed correctly because BlockingIOMulticastSender.java's multicast socket will read incomplete DatagramPacket(max 16k bytes) once.
What do you think?
Regards,
Bongjae Chang
----- Original Message -----
From: "Bongjae Chang" <bongjae.chang_at_gmail.com>
To: <joe.fialli_at_oracle.com>
Cc: <dev_at_shoal.dev.java.net>
Sent: Wednesday, March 10, 2010 1:53 PM
Subject: Re: question concerning abstract transport branch MessageImpl.MAX_TOTAL_MESSAGE_LENGTH
> Hi Joe,
>
> I agree that the size is small.
>
> Actually, I couldn't determine the default size(8k was maybe temporary size). :-)
>
> So I just set the default to Socket's send(receive) buffer size.
>
> i.g. Socket#getSendBufferSize(), Socket#getReceiveBufferSize(), DatagramSocket#getReceiveBufferSize(), DatagramSocket#getSendBufferSize() and ServerSocket#getReceiveBufferSize() were 8k.
>
> So I also think that you had better change the current constant value.
>
> But you should consider the default allocation size of DatagramPacket in BlockingIOMulticastSender.java. The default allocation size is about 16k.
>
> So I think that maybe you should also change the default allocation size in BlockingIOMulticastSender.java if you will change MessageImpl.MAX_TOTAL_MESSAGE_LENGTH.
>
> In addition, I think that it is also better that BlockingIOMulticastSender.java considers MulticastSocket#setSendBufferSize() or #setReceiveBufferSize() APIs.(But I don't know how it has the advantage of efficiency because I didn't have tests of those APIs).
>
> Thanks.
>
>
> Regards,
> Bongjae Chang
>
>
> ----- Original Message -----
> From: "Joseph Fialli" <joe.fialli_at_oracle.com>
> To: <bongjae.chang_at_gmail.com>
> Cc: <dev_at_shoal.dev.java.net>
> Sent: Wednesday, March 10, 2010 1:10 AM
> Subject: question concerning abstract transport branch MessageImpl.MAX_TOTAL_MESSAGE_LENGTH
>
>
> > Bongjae,
> >
> > We have found that the default MessageImpl.MAX_TOTAL_MESSAGE_LENGTH is
> > set to a rather modest size of 8K.
> > This size is small for a particular use case we have in mind. I was
> > looking to seek your advice on the advantages
> > of having the default size so small.
> >
> > I was considering the following options:
> >
> > 1. Change the current constant value from 8192 to 64K. // requiring
> > the least amount of change by potentially having a negative unforeseen
> > impact.
> >
> > 2. Leave the default as is but make this constant configurable via a
> > Shoal property that is specified when gms client joins group.
> >
> > Before I started working on this change, I wanted to understand the
> > motivation behind the current value.
> >
> > Thanks in advance for your comments.
> >
> > -Joe
> >
> >