[BUG] - SIGHUP causes full re-validation

[grim-i-am]

Internal/External
External

Area
Other

Summary
Sending a SIGHUP signal to the cardano-node process as per understanding-your-configuration-files-and-how-to-use-them:

You can tell the node that the topology configuration file changed by sending a SIGHUP signal to the cardano-node process, e.g. pkill -HUP cardano-node. After receiving the signal, cardano-node will re-read the file and restart all dns resolution. Please note that this only applies to the topology configuration file!

results in a full re-validation.

Steps to reproduce
go to a terminal on a machine running a node instance.
issue command pkill -HUP cardano-node

Expected behavior
The node should just continue synchronising with its new list of peers after re-reading the topology config file and not perform a re-validation.

System info (please complete the following information):

• OS Name: Linux Mint
• OS Version 20.3
• Node version 1.34.1 - linux-x86_64 - ghc-8.10
• CLI version 1.34.1 - linux-x86_64 - ghc-8.10

[coot]

First of all thanks for reporting the problem. SIGHUP is only supported for p2p node, for non-p2p mode the node will exit, possibly leaving it in a dirty state. The PR #3896, will ignore SIGHUP for non-p2p mode (just log a warning message which says that reloading topology is not supported in non-p2p mode).