[Gluster-users] TCP connection incresement when reconfigure and question about multi-graph

[HU Zhong]

Hi, all.

I set up a dht system, and sent a HUP signal to client  to trigger the reconfiguration.
But i found that the TCP connection established increased by the number
of bricks(the number of glusterfsd progress). 

$ ps -ef | grep glusterfs
root      8579     1  0 11:28 ?        00:00:00 glusterfsd -f /home/huz/dht/server.vol -l /home/huz/dht/server.log -L TRACE
root      8583     1  0 11:28 ?        00:00:00 glusterfsd -f /home/huz/dht/server2.vol -l /home/huz/dht/server2.log -L TRACE
root      8587     1  0 11:28 ?        00:00:00 glusterfsd -f /home/huz/dht/server3.vol -l /home/huz/dht/server3.log -L TRACE
root      8595     1  1 11:28 ?        00:00:00 glusterfs -f /home/huz/dht/client.vol -l /home/huz/dht/client.log -L TRACE /home/huz/mnt

$ sudo netstat -ntp | grep glusterfs
tcp        0      0 127.0.0.1:6998          127.0.0.1:1023          ESTABLISHED 8579/glusterfsd 
tcp        0      0 127.0.0.1:1021          127.0.0.1:7000          ESTABLISHED 8595/glusterfs  
tcp        0      0 127.0.0.1:7000          127.0.0.1:1021          ESTABLISHED 8587/glusterfsd 
tcp        0      0 127.0.0.1:1023          127.0.0.1:6998          ESTABLISHED 8595/glusterfs  
tcp        0      0 127.0.0.1:6999          127.0.0.1:1022          ESTABLISHED 8583/glusterfsd 
tcp        0      0 127.0.0.1:1022          127.0.0.1:6999          ESTABLISHED 8595/glusterfs  

huz at furutuki:~/dht$ sudo kill -s HUP 8595

huz at furutuki:~/dht$ sudo netstat -ntp | grep glusterfs
tcp        0      0 127.0.0.1:6998          127.0.0.1:1023          ESTABLISHED 8579/glusterfsd 
tcp        0      0 127.0.0.1:1021          127.0.0.1:7000          ESTABLISHED 8595/glusterfs  
tcp        0      0 127.0.0.1:6999          127.0.0.1:1019          ESTABLISHED 8583/glusterfsd 
tcp        0      0 127.0.0.1:7000          127.0.0.1:1021          ESTABLISHED 8587/glusterfsd 
tcp        0      0 127.0.0.1:1018          127.0.0.1:7000          ESTABLISHED 8595/glusterfs  
tcp        0      0 127.0.0.1:6998          127.0.0.1:1020          ESTABLISHED 8579/glusterfsd 
tcp        0      0 127.0.0.1:1023          127.0.0.1:6998          ESTABLISHED 8595/glusterfs  
tcp        0      0 127.0.0.1:7000          127.0.0.1:1018          ESTABLISHED 8587/glusterfsd 
tcp        0      0 127.0.0.1:1019          127.0.0.1:6999          ESTABLISHED 8595/glusterfs  
tcp        0      0 127.0.0.1:6999          127.0.0.1:1022          ESTABLISHED 8583/glusterfsd 
tcp        0      0 127.0.0.1:1022          127.0.0.1:6999          ESTABLISHED 8595/glusterfs  
tcp        0      0 127.0.0.1:1020          127.0.0.1:6998          ESTABLISHED 8595/glusterfs 

lookup at the example above, the TCP connection increased by 3. I wonder if this is the normal? 

Further, I checked the log of client, and found something like this:
 [2011-04-07 11:28:06.92451] T [rpc-clnt.c:405:rpc_clnt_reconnect] 0-client0: breaking reconnect chain
 [2011-04-07 11:28:06.92596] T [rpc-clnt.c:405:rpc_clnt_reconnect] 0-client1: breaking reconnect chain
 [2011-04-07 11:28:06.92648] T [rpc-clnt.c:405:rpc_clnt_reconnect] 0-client2: breaking reconnect chain

 [2011-04-07 11:29:05.101120] T [rpc-clnt.c:405:rpc_clnt_reconnect] 1-client0: breaking reconnect chain
 [2011-04-07 11:29:05.101254] T [rpc-clnt.c:405:rpc_clnt_reconnect] 1-client1: breaking reconnect chain
 [2011-04-07 11:29:05.101307] T [rpc-clnt.c:405:rpc_clnt_reconnect] 1-client2: breaking reconnect chain

Apparently, there are two graphs in the system.(glusterFS 3.1.3 output graph id in gf_log function).
My understanding is that there should only be 1 graph which is consist of xlators configured in the .vol file.
Due to the HUP signal, the GlusterFS set up a new graph and initialize new TCP connections, so that i got
the result above. My question is why there need to be two graphs or more?