Re: [HACKERS] RE: [QUESTIONS] Identity Crisis

Len Morgan writes:
>> My question is this: Is there a way to identify on the line
>> which starts up the backends, which host is starting it?  In other
>> words, if I do ps -ax on the server, can I have an ip address or host
>> name show up to let me know which host is connected to which backend?

Hackers, if anyone does something with setting the backend process title,
this seems like a good idea to me.

However, a feature that may or may not show up in 6.4 is not going to
help Len with his immediate problem.  Len, I'd suggest a couple of
things you can do today:

1. netstat on your server will show open TCP connections.  Look for
   connections to port 5432 at your end.  If you have a lot of users
   it might be hard to spot the culprit --- but I suspect that looking
   for the machine that shows a number of open connections, not just
   one, will do it.

2. If that doesn't work, but you can identify a backend process that's
   been laying around for awhile, you can use "lsof" to find out
   which network connection leads to that process.  For example,
   I use ps to find that process 21309 is a backend, then:

$ lsof -p 21309
COMMAND    PID     USER   FD   TYPE     DEVICE SIZE/OFF  INODE NAME
postgres 21309 postgres    3u  inet 0x0d2d1b00      0t0    TCP *:5432 (LISTEN)
postgres 21309 postgres    5u  inet 0x0d749000    0t302    TCP localhost:5432->localhost:2325 (ESTABLISHED)
postgres 21309 postgres    6u  inet 0x0d749000    0t302    TCP localhost:5432->localhost:2325 (ESTABLISHED)
(lots of non-inet open files for this process snipped)

So I see the client connected to this server is at port 2325 on
localhost.

lsof (list open files) might already be installed on your machine,
if not see http://www-rcd.cc.purdue.edu/abe/.  It's an invaluable
tool for debugging all sorts of Unix problems, well worth having
in your sysadmin kit.

            regards, tom lane