hi everybody,

i try to user dynamic mode with configless mode with slurm 24.11.3 and upgrade to 24.11.4

with slurmd and i found a problem.

slurmctld is a container with docker, and my node is outside the container network .

slurmctld register my ip with a function getpeeraddr on the slurmctld socket.
but my ip connected to the socket come from the docker nat/bridge so slurmctld register my ip bridged ( not my real ip ) that is to say the docker gateway (172.20.0.1)

scontrol show node

-------------------------

NodeName=ltlsbubble1 Arch=x86_64 CoresPerSocket=4
..
NodeAddr=172.20.0.1 NodeHostName=ltlsbubble1 Version=24.11.4

so the node go down after the "not pinging it" timeout

i try to update the config

scontrol uupdate NodeName=ltlsbubble1 NodeAddr=xx.xx.xx.xx

but a the first

scontrol reconfigure

it comes back to : NodeAddr=172.20.0.1

in normal mode

-------------------

scontrol show node
NodeName=ltlsbubble1 Arch=x86_64 CoresPerSocket=4
..
NodeAddr=ltlsbubble1 NodeHostName=ltlsbubble1 Version=24.11.4

in normal mode NodeAddr is the same than NodeName , so it use DNS resolution for communication.

to verify my hypothesis, i go to the c code of slurm, identify the register function and replace it with the same mechanism than normal node

in src/slurmctld/node_mgr.c

i replace :

set_node_comm_name(node_ptr, comm_name, reg_msg->hostname);

set_node_comm_name(node_ptr, NULL, reg_msg->hostname);

i rebuild slutmctld with this patch and try it with dynamic mode , it works like expected

scontrol show node
NodeName=ltlsbubble1 Arch=x86_64 CoresPerSocket=4
..
NodeAddr=ltlsbubble1 NodeHostName=ltlsbubble1 Version=24.1

no ip in nodeAddr , but only the nodename, so it use DNS resolution . the node works fine and no goes down for timeout ping

so my question :

can we have an option to force DNS resolution instead ip discover in Dynamic mode ?

( i try the option cloud_dns, but it not seems the purpose of this option)

best regard,

Stephane