Trouble with extremely long running SNMP tasks with Rittal PDU

Troubleshooting
1

Hello, I have trouble with a Rittal PDU managed 7979.440 (pdu1 is the primary one and I have a second pdu2 in “secondary” mode connected to the “primary” one). The SNMP walk/scan takes a very long time when done manually and I run into timeouts. I have already tried limiting the plugins for the host to the plugins with prefix cmciii but that does not help.

Does anyone have experience with getting these long-running SNMP tasks on Rittal PDUs to work with Checkmk?

CMK version: Checkmk raw 2.4.0-2025.11.17
OS version: Docker on Ubuntu 24.04

Error message:

Output of “cmk --debug -vvn hostname”: (If it is a problem with checks or plugins)

full output.txt (174.3 KB)

2

The important question here is where in the whole process it takes the time.

I think you only need the “cmciii” section of data or?
Most times, with such devices, i look at runtime where the time is spent and decide then if i need the data or not.

What you can do for a test is

  • disable all SNMP section for this device and leave only the “cmciii” section active
  • do the same as with your output and look for the time spent
  • if already the cmciii takes this long then you have bad luck with this device

With Rittal devices you have only SNMP and Modbus as connection options and nothing else :frowning:

3

Actually, my Rittal PDU has a RedFish interface. However, I have no luck with this either.

With Rittal devices you have only SNMP and Modbus as connection options and nothing else 

Actually, my Rittal PDU has a RedFish interface. However, I have no luck with this either.

OMD[mgm]:~$ cmk --debug -vvn pdu1
value store: loading from disk
Checkmk version 2.4.0-2025.11.17
+ FETCHING DATA
  Source: SourceInfo(hostname='pdu1', ipaddress='10.200.53.3', ident='special_redfish', fetcher_type=<FetcherType.SPECIAL_AGENT: 6>, source_type=<SourceType.HOST: 1>)
[cpu_tracking] Start [7c7409d1e600]
Read from cache: AgentFileCache(path_template=/omd/sites/mgm/tmp/check_mk/data_source_cache/special_redfish/pdu1, max_age=MaxAge(checking=0, discovery=90.0, inventory=90.0), simulation=False, use_only_cache=False, file_cache_mode=6)
Not using cache (does not exist)
Calling: /omd/sites/mgm/lib/python3/cmk/plugins/redfish/libexec/agent_redfish -u redfish --password-id uuidec941aec-dd80-4d2b-893d-da043582eac2:/omd/sites/mgm/var/check_mk/passwords_merged -p 443 -P https -m '' -n Memory,Power,Processors,Thermal,FirmwareInventory,NetworkAdapters,NetworkInterfaces,EthernetInterfaces,Storage,ArrayControllers,SmartStorage,HostBusAdapters,PhysicalDrives,LogicalDrives,Drives,Volumes,SimpleStorage -c '' --timeout 10 --retries 2 10.200.53.3
Get data from program
[cpu_tracking] Stop [7c7409d1e600 - Snapshot(process=posix.times_result(user=0.0, system=0.0, children_user=0.27, children_system=0.1, elapsed=1.4100000001490116))]
  Source: SourceInfo(hostname='pdu1', ipaddress='10.200.53.3', ident='piggyback', fetcher_type=<FetcherType.PIGGYBACK: 4>, source_type=<SourceType.HOST: 1>)
[cpu_tracking] Start [7c74093ada60]
Read from cache: NoCache(path_template=/dev/null, max_age=MaxAge(checking=0.0, discovery=0.0, inventory=0.0), simulation=False, use_only_cache=False, file_cache_mode=1)
0 piggyback files for 'pdu1'.
0 piggyback files for '10.200.53.3'.
Get piggybacked data
[cpu_tracking] Stop [7c74093ada60 - Snapshot(process=posix.times_result(user=0.0, system=0.0, children_user=0.0, children_system=0.0, elapsed=0.0))]
[cpu_tracking] Start [7c7409f77e60]
+ PARSE FETCHER RESULTS
  HostKey(hostname='pdu1', source_type=<SourceType.HOST: 1>)  -> Add sections: []
Received no piggyback data
0 piggyback files for 'pdu1'.
[cpu_tracking] Stop [7c7409f77e60 - Snapshot(process=posix.times_result(user=0.0, system=0.0, children_user=0.0, children_system=0.0, elapsed=0.0))]
[special_redfish] AttributeError: 'NoneType' object has no attribute 'replace'(!!), [piggyback] Success (but no data found for this host), execution time 1.4 sec | execution_time=1.410 user_time=0.000 system_time=0.000 children_user_time=0.270 children_system_time=0.100 cmk_time_ds=1.040 cmk_time_agent=0.000
Agent exited with code 1: Agent failed - please submit a crash report! (Crash-ID: 2252c692-d03d-11f0-881c-f2efcc654044)

Traceback (most recent call last):
  File "/omd/sites/mgm/lib/python3/cmk/special_agents/v0_unstable/agent_common.py", line 151, in _special_agent_main_core
    return main_fn(args)
           ^^^^^^^^^^^^^
  File "/omd/sites/mgm/lib/python3/cmk/plugins/redfish/special_agents/agent_redfish.py", line 800, in agent_redfish_main
    get_information(redfishobj)
  File "/omd/sites/mgm/lib/python3/cmk/plugins/redfish/special_agents/agent_redfish.py", line 545, in get_information
    systems_col = fetch_data(redfishobj.redfish_connection, systems_url, "System")
                  ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/omd/sites/mgm/lib/python3/cmk/plugins/redfish/special_agents/agent_redfish.py", line 263, in fetch_data
    response_url = client.get(url, None)
                   ^^^^^^^^^^^^^^^^^^^^^
  File "/omd/sites/mgm/lib/python3/cmk/plugins/redfish/special_agents/agent_redfish.py", line 117, in get
    return self._client.get(url, timeout=timeout)
           ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/omd/sites/mgm/lib/python3.12/site-packages/redfish/rest/v1.py", line 651, in get
    return self._rest_request(path, method='GET', args=args,
           ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/omd/sites/mgm/lib/python3.12/site-packages/redfish/rest/v1.py", line 1140, in _rest_request
    return super(HttpClient, self)._rest_request(path=path, method=method,
           ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/omd/sites/mgm/lib/python3.12/site-packages/redfish/rest/v1.py", line 810, in _rest_request
    reqpath = path.replace('//', '/')
              ^^^^^^^^^^^^
AttributeError: 'NoneType' object has no attribute 'replace'(!!)


[cpu_tracking] Start [7c74093ada60]
Read from cache: NoCache(path_template=/dev/null, max_age=MaxAge(checking=0.0, discovery=0.0, inventory=0.0), simulation=False, use_only_cache=False, file_cache_mode=1)
0 piggyback files for 'slgmvzmz2-pdu1'.
0 piggyback files for '10.200.53.3'.
Get piggybacked data
[cpu_tracking] Stop [7c74093ada60 - Snapshot(process=posix.times_result(user=0.0, system=0.0, children_user=0.0, children_system=0.0, elapsed=0.0))]
[cpu_tracking] Start [7c7409f77e60]
+ PARSE FETCHER RESULTS
  HostKey(hostname='slgmvzmz2-pdu1', source_type=<SourceType.HOST: 1>)  -> Add sections: []
Received no piggyback data
0 piggyback files for 'slgmvzmz2-pdu1'.
[cpu_tracking] Stop [7c7409f77e60 - Snapshot(process=posix.times_result(user=0.0, system=0.0, children_user=0.0, children_system=0.0, elapsed=0.0))]
[special_redfish] AttributeError: 'NoneType' object has no attribute 'replace'(!!), [piggyback] Success (but no data found for this host), execution time 1.4 sec | execution_time=1.410 user_time=0.000 system_time=0.000 children_user_time=0.270 children_system_time=0.100 cmk_time_ds=1.040 cmk_time_agent=0.000
Agent exited with code 1: Agent failed - please submit a crash report! (Crash-ID: 2252c692-d03d-11f0-881c-f2efcc654044)

Traceback (most recent call last):
  File "/omd/sites/mgm/lib/python3/cmk/special_agents/v0_unstable/agent_common.py", line 151, in _special_agent_main_core
    return main_fn(args)
           ^^^^^^^^^^^^^
  File "/omd/sites/mgm/lib/python3/cmk/plugins/redfish/special_agents/agent_redfish.py", line 800, in agent_redfish_main
    get_information(redfishobj)
  File "/omd/sites/mgm/lib/python3/cmk/plugins/redfish/special_agents/agent_redfish.py", line 545, in get_information
    systems_col = fetch_data(redfishobj.redfish_connection, systems_url, "System")
                  ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/omd/sites/mgm/lib/python3/cmk/plugins/redfish/special_agents/agent_redfish.py", line 263, in fetch_data
    response_url = client.get(url, None)
                   ^^^^^^^^^^^^^^^^^^^^^
  File "/omd/sites/mgm/lib/python3/cmk/plugins/redfish/special_agents/agent_redfish.py", line 117, in get
    return self._client.get(url, timeout=timeout)
           ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/omd/sites/mgm/lib/python3.12/site-packages/redfish/rest/v1.py", line 651, in get
    return self._rest_request(path, method='GET', args=args,
           ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/omd/sites/mgm/lib/python3.12/site-packages/redfish/rest/v1.py", line 1140, in _rest_request
    return super(HttpClient, self)._rest_request(path=path, method=method,
           ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/omd/sites/mgm/lib/python3.12/site-packages/redfish/rest/v1.py", line 810, in _rest_request
    reqpath = path.replace('//', '/')
              ^^^^^^^^^^^^
AttributeError: 'NoneType' object has no attribute 'replace'(!!)
4

Is it possible to get the output from a curl https://your-device/redfish/v1 ?

If it is a PDU you can try to use the redfish agent for PDUs.

That is accessable with the second redfish rule inside the other integrations section.

5

Long running SNMP on Rittal PDU is what I would expect / experienced as well. For the Rittal PDU we therefor usually changed to an 5Min Interval and a 3Min Timeout setting in CheckMK.