Forcing diagmond to use a specific IP address

[Bruno Gallant (Domtar)]

Hello,

we run a lot of SAP instances on our servers, running on Oracle databases, in ServiceGuard packages with different IP addresses. We have a logical system with our IP port numbers across the business, so that we have an idea of what is running on what port. One of the Oracle listeners is using port 1508 on a particular server, which is also the port that diagmond wants to use.

Now, IP ports are binded to a specific IP address. The oracle listener is only using the port connected to the ServiceGuard IP address of the specific Oracle package that contains it.

diagmond, on the other hand, is greedy, and wants to use port 1508 on any IP address on the server.

Here are some lsof outputs on two different machines. I will only list the IPv4 type, to make things clearer:

Machine not running the Oracle listener
diagmond 15305 root 4u IPv4 0xe00000019f340740 0t0 TCP *:58094 (LISTEN)
diagmond 15305 root 5u IPv4 0xe00000019eb7c3c0 0t0 TCP *:diagmond (LISTEN)


machine running the Oracle listener on port 1508:

diagmond 22425 root 4u IPv4 0xe0000001d39a9040 0t0 TCP *:53885 (LISTEN)

Here is the netstat output on the server not running the listener:

netstat -a | grep diagmond
tcp 0 0 *.diagmond *.* LISTEN



My question is: can diagmond be forced to use the port only on the host IP, instead of trying to grab all of them?

Thank you.

[Sameer_Nirmal]

I think you need to disable remote access of STM running on the local host.

Refer the release notes of STM available at http://docs.hp.com/en/diag/archive/str_0112_11i.htm where you will find the required configuration details to achieve this.

I hope this will help in this scenario.

[Bruno Gallant (Domtar)]

I enabled LOCAL_ONLY_ENABLE 1 in the file /var/stm/config/sys/diagmond.cfg, and when I restart diagmond, it does not bind to port 1508 at all, which is not the behavior I am looking for.

I would like the daemon to bind only on the server's address and port 1508, instead of *:1508.

If it cannot be forced to do that, I know I'll have to change the Oracle listener's port, but I don't want to do that if it can be avoided.

Thank you.

[rick jones]

A couple things - IP does not have ports. TCP and UDP have ports. IP has addresses and a protocol field (which specifies TCP, UDP, etc)

When you set the "local only" option I'd guess that told diagmond to only open a Unix Domain socket so that only things running on the local system could reach it.

I take it that port 1508 is derived from the logical system for picking port numbers? Any particular reason why it is using a port number below 5000? Or below 16384? I think you will find that using port numbers between 16384 and tcp_smallest_anon_port (ndd /dev/tcp tcp_smallest_anon_port) will be less likely to encounter conflicts with other services. Perhaps even 5000 to tcp_smallest_anon_port.

So, while it would be goodness to ring-up the response center (no sense letting those support contracts sit idle :) and ask for an enhancement to diagmond to allow the IP address to which it binds to be configured somehow, it would also be goodness to take a look at the process you are using to pick port numbers and see if it can be a bit more robust as well.