some 'weird' observation regarding HA

[seanx]

I have seen some behaviors with clustering and hope to get some explanation.

I have two server instances running on one server. Client program on another machine invokes Stateful session bean deployed to this two server cluster.

First, I have both servers defined in client side jndi.properties. Server1 listens on 2100 and Server2 listens on 1100 for HAJNDI. I start Server1 and then Server2.

Then I start my client. From the log, I can tell it went to Server1. But from the network trace, I find the client first talks to Server1 on 2100 and then Server1 and client keep on talking on some high ports. What puzzles me is then the client talks to server2 on 1100 and have some conversation with Server2 on some high ports. Although the final result is from Server1, client still talks to Server2. Why?

Below the part of the network trace.

thanks,

-SeanX

nmcpdc117.ny.fw.gs.com -> nhcpdsw35.inz.test.gs.com TCP D=2100 S=46229 Syn Seq=3
095983683 Len=0 Win=8760
nhcpdsw35.inz.test.gs.com -> nmcpdc117.ny.fw.gs.com TCP D=46229 S=2100 Syn Ack=3
095983684 Seq=3817123930 Len=0 Win=8760
nmcpdc117.ny.fw.gs.com -> nhcpdsw35.inz.test.gs.com TCP D=2100 S=46229 Ack=3
817123931 Seq=3095983684 Len=0 Win=8760
nhcpdsw35.inz.test.gs.com -> nmcpdc117.ny.fw.gs.com TCP D=46229 S=2100 Ack=3
095983684 Seq=3817123931 Len=4 Win=8760
nmcpdc117.ny.fw.gs.com -> nhcpdsw35.inz.test.gs.com TCP D=2100 S=46229 Ack=3
817123935 Seq=3095983684 Len=0 Win=8760
nhcpdsw35.inz.test.gs.com -> nmcpdc117.ny.fw.gs.com TCP D=46229 S=2100 Ack=3
095983684 Seq=3817123935 Len=79 Win=8760
nmcpdc117.ny.fw.gs.com -> nhcpdsw35.inz.test.gs.com TCP D=2100 S=46229 Ack=3
817124014 Seq=3095983684 Len=0 Win=8760
nhcpdsw35.inz.test.gs.com -> nmcpdc117.ny.fw.gs.com TCP D=46229 S=2100 Fin Ack=3
095983684 Seq=3817124014 Len=901 Win=8760
nmcpdc117.ny.fw.gs.com -> nhcpdsw35.inz.test.gs.com TCP D=2100 S=46229 Ack=3
817124916 Seq=3095983684 Len=0 Win=8760
nmcpdc117.ny.fw.gs.com -> nhcpdsw35.inz.test.gs.com TCP D=49152 S=46230 Syn Seq=
3096088654 Len=0 Win=8760
nhcpdsw35.inz.test.gs.com -> nmcpdc117.ny.fw.gs.com TCP D=46230 S=49152 Syn Ack=
3096088655 Seq=3817216774 Len=0 Win=8760
nmcpdc117.ny.fw.gs.com -> nhcpdsw35.inz.test.gs.com TCP D=49152 S=46230 Ack=
3817216775 Seq=3096088655 Len=0 Win=8760
nmcpdc117.ny.fw.gs.com -> nhcpdsw35.inz.test.gs.com TCP D=49152 S=46230 Ack=
3817216775 Seq=3096088655 Len=7 Win=8760
nhcpdsw35.inz.test.gs.com -> nmcpdc117.ny.fw.gs.com TCP D=46230 S=49152 Ack=
3096088662 Seq=3817216775 Len=0 Win=8760
nhcpdsw35.inz.test.gs.com -> nmcpdc117.ny.fw.gs.com TCP D=46230 S=49152 Ack=
3096088662 Seq=3817216775 Len=21 Win=8760
nmcpdc117.ny.fw.gs.com -> nhcpdsw35.inz.test.gs.com TCP D=49152 S=46230 Ack=
3817216796 Seq=3096088662 Len=0 Win=8760
nmcpdc117.ny.fw.gs.com -> nhcpdsw35.inz.test.gs.com TCP D=49152 S=46230 Ack=
3817216796 Seq=3096088662 Len=20 Win=8760
nmcpdc117.ny.fw.gs.com -> nhcpdsw35.inz.test.gs.com TCP D=49152 S=46230 Ack=
3817216796 Seq=3096088682 Len=451 Win=8760
nhcpdsw35.inz.test.gs.com -> nmcpdc117.ny.fw.gs.com TCP D=46230 S=49152 Ack=
3096089133 Seq=3817216796 Len=0 Win=8760
nhcpdsw35.inz.test.gs.com -> nmcpdc117.ny.fw.gs.com TCP D=46230 S=49152 Ack=
3096089133 Seq=3817216796 Len=335 Win=8760
nmcpdc117.ny.fw.gs.com -> nhcpdsw35.inz.test.gs.com TCP D=51024 S=46231 Syn Seq=
3096134608 Len=0 Win=8760
nhcpdsw35.inz.test.gs.com -> nmcpdc117.ny.fw.gs.com TCP D=46231 S=51024 Syn Ack=
3096134609 Seq=3817348647 Len=0 Win=8760
nmcpdc117.ny.fw.gs.com -> nhcpdsw35.inz.test.gs.com TCP D=51024 S=46231 Ack=
3817348648 Seq=3096134609 Len=0 Win=8760
nmcpdc117.ny.fw.gs.com -> nhcpdsw35.inz.test.gs.com TCP D=51024 S=46231 Ack=
3817348648 Seq=3096134609 Len=7 Win=8760
nhcpdsw35.inz.test.gs.com -> nmcpdc117.ny.fw.gs.com TCP D=46231 S=51024 Ack=
3096134616 Seq=3817348648 Len=0 Win=8760
nhcpdsw35.inz.test.gs.com -> nmcpdc117.ny.fw.gs.com TCP D=46231 S=51024 Ack=
3096134616 Seq=3817348648 Len=21 Win=8760
nmcpdc117.ny.fw.gs.com -> nhcpdsw35.inz.test.gs.com TCP D=51024 S=46231 Ack=
3817348669 Seq=3096134616 Len=0 Win=8760
nmcpdc117.ny.fw.gs.com -> nhcpdsw35.inz.test.gs.com TCP D=51024 S=46231 Ack=
3817348669 Seq=3096134616 Len=20 Win=8760
nmcpdc117.ny.fw.gs.com -> nhcpdsw35.inz.test.gs.com TCP D=51024 S=46231 Ack=
3817348669 Seq=3096134636 Len=451 Win=8760
nhcpdsw35.inz.test.gs.com -> nmcpdc117.ny.fw.gs.com TCP D=46231 S=51024 Ack=
3096135087 Seq=3817348669 Len=0 Win=8760
nhcpdsw35.inz.test.gs.com -> nmcpdc117.ny.fw.gs.com TCP D=46231 S=51024 Ack=
3096135087 Seq=3817348669 Len=335 Win=8760
nmcpdc117.ny.fw.gs.com -> nhcpdsw35.inz.test.gs.com TCP D=49152 S=46230 Ack=
3817217131 Seq=3096089133 Len=0 Win=8760
nmcpdc117.ny.fw.gs.com -> nhcpdsw35.inz.test.gs.com TCP D=2100 S=46229 Fin Ack=3
817124916 Seq=3095983684 Len=0 Win=8760
nhcpdsw35.inz.test.gs.com -> nmcpdc117.ny.fw.gs.com TCP D=46229 S=2100 Ack=3
095983685 Seq=3817124916 Len=0 Win=8760
nmcpdc117.ny.fw.gs.com -> nhcpdsw35.inz.test.gs.com TCP D=1100 S=46232 Syn Seq=3
096239768 Len=0 Win=8760
nhcpdsw35.inz.test.gs.com -> nmcpdc117.ny.fw.gs.com TCP D=46232 S=1100 Syn Ack=3
096239769 Seq=3817397800 Len=0 Win=8760
nmcpdc117.ny.fw.gs.com -> nhcpdsw35.inz.test.gs.com TCP D=1100 S=46232 Ack=3
817397801 Seq=3096239769 Len=0 Win=8760
nhcpdsw35.inz.test.gs.com -> nmcpdc117.ny.fw.gs.com TCP D=46232 S=1100 Ack=3
096239769 Seq=3817397801 Len=4 Win=8760
nmcpdc117.ny.fw.gs.com -> nhcpdsw35.inz.test.gs.com TCP D=1100 S=46232 Ack=3
817397805 Seq=3096239769 Len=0 Win=8760
nmcpdc117.ny.fw.gs.com -> nhcpdsw35.inz.test.gs.com TCP D=51024 S=46231 Ack=
3817349004 Seq=3096135087 Len=0 Win=8760
nhcpdsw35.inz.test.gs.com -> nmcpdc117.ny.fw.gs.com TCP D=46232 S=1100 Ack=3
096239769 Seq=3817397805 Len=79 Win=8760
nmcpdc117.ny.fw.gs.com -> nhcpdsw35.inz.test.gs.com TCP D=1100 S=46232 Ack=3
817397884 Seq=3096239769 Len=0 Win=8760
nhcpdsw35.inz.test.gs.com -> nmcpdc117.ny.fw.gs.com TCP D=46232 S=1100 Fin Ack=3
096239769 Seq=3817397884 Len=901 Win=8760
nmcpdc117.ny.fw.gs.com -> nhcpdsw35.inz.test.gs.com TCP D=1100 S=46232 Ack=3
817398786 Seq=3096239769 Len=0 Win=8760
nmcpdc117.ny.fw.gs.com -> nhcpdsw35.inz.test.gs.com TCP D=1100 S=46232 Fin Ack=3
817398786 Seq=3096239769 Len=0 Win=8760
nhcpdsw35.inz.test.gs.com -> nmcpdc117.ny.fw.gs.com TCP D=46232 S=1100 Ack=3
096239770 Seq=3817398786 Len=0 Win=8760
nmcpdc117.ny.fw.gs.com -> nhcpdsw35.inz.test.gs.com TCP D=49152 S=46230 Ack=
3817217131 Seq=3096089133 Len=1 Win=8760
nhcpdsw35.inz.test.gs.com -> nmcpdc117.ny.fw.gs.com TCP D=46230 S=49152 Ack=
3096089134 Seq=3817217131 Len=1 Win=8760
nmcpdc117.ny.fw.gs.com -> nhcpdsw35.inz.test.gs.com TCP D=49152 S=46230 Ack=
3817217132 Seq=3096089134 Len=0 Win=8760
nmcpdc117.ny.fw.gs.com -> nhcpdsw35.inz.test.gs.com TCP D=49152 S=46230 Ack=
3817217132 Seq=3096089134 Len=318 Win=8760
nmcpdc117.ny.fw.gs.com -> nhcpdsw35.inz.test.gs.com TCP D=49152 S=46230

[slaboure]

Well, at first sight, I would say that it is logical.

When you start a JNDI server on a give port, this port is *only* used to download the stub necessary to access the JNDI server, that's all. The port is *not* used for the actual communication between the client and the server.

The port that is used for the actual communication is dynamically attributed (you can set it in the MBEAN property though), which is why I think it is a "high" port.

In 4.0, the JNDI port used for communications will be the same as the one used for accessing your containers, ... in 3.0, all containers and almost all services already share a single port but some services, like JNDI, don't use it yet.

cheers,



Sacha

[seanx]

Sacha,
Thank you for the reply.
I am sorry if I was not clear. My confusion is not the high port but the fact that client program talks to server2 on HAJNDI port(1100) after it talks to server1 on HAJNDI port(2100).
Why does the client need to talk to server2 when server1 is responding?

Also you mention all the ports will the same in 4.0. Do you know when 4.0 will be released? thanks.

[slaboure]

> I am sorry if I was not clear. My confusion is not
> the high port but the fact that client program talks
> to server2 on HAJNDI port(1100) after it talks to
> server1 on HAJNDI port(2100).

I don't have an idea just like this. I agree, I would also think that only one connection is done.

> Also you mention all the ports will the same in 4.0.
> Do you know when 4.0 will be released? thanks.

No ;) Saying 4.0 is like saying "the future". But real work for 4.0 will start soon and I am pretty sure that the delay between 3 and 4 will be shorter than the one between 2 and 3.

Cheers,