Setting a non-default retries value for any module affects all modules

[lukeyeager]

Host operating system: output of uname -a

$ uname -srmo
Linux 6.6.7-arch1-1 x86_64 GNU/Linux

snmp_exporter version: output of snmp_exporter -version

$ ./snmp_exporter --version
snmp_exporter, version 0.25.0 (branch: HEAD, revision: 9c42d6c874d479314e612bca69558c81f8e26287)
  build user:       root@880115266f70
  build date:       20231210-10:05:18
  go version:       go1.21.5
  platform:         linux/amd64
  tags:             netgo

What device/snmpwalk OID are you using?

Anything. I picked the first two modules in the default snmp.yml to prove the point.

If this is a new device, please link to the MIB(s).

n/a

What did you do that produced an error?

With an unmodified snmp.yml, trying to query a non-functional SNMP server retries 3x (the default). This is good:

$ sudo nc -l -u -p 161
$ ./snmp_exporter --config.file=snmp.yml
$ curl 'localhost:9116/snmp?target=localhost&module=apcups'
An error has occurred while serving metrics:

error collecting metric Desc{fqName: "snmp_error", help: "Error scraping target", constLabels: {module="apcups"}, variableLabels: {}}: error getting target localhost: request timeout (after 3 retries)

Now, look what happens when I edit "retries" for a different module (arista_sw). The retries value for the apcups module has changed, too!

$ git diff
diff --git a/snmp.yml b/snmp.yml
index ce625d3..c296394 100644
--- a/snmp.yml
+++ b/snmp.yml
@@ -2372,6 +2372,7 @@ modules:
       - labelname: rPDU2BankStatusIndex
         type: gauge
   arista_sw:
+    retries: 0
     walk:
     - 1.3.6.1.4.1.30065.3.1.1
     metrics:

$ curl 'localhost:9116/snmp?target=localhost&module=apcups'
An error has occurred while serving metrics:

error collecting metric Desc{fqName: "snmp_error", help: "Error scraping target", constLabels: {module="apcups"}, variableLabels: {}}: error getting target localhost: request timeout (after 0 retries)

What did you expect to see?

I expected that editing "retries" for one module would not affect the retries for another module.