Troubleshoot SMF Error Log "All Peers Are Dead"

Introduction

This document describes how to troubleshoot Session Management Function (SMF) log alert related to All Peers are Dead, Setting status code to 0.

Problem

The session impact was reported on the SMF.

Analysis

Log All Peers are Dead

The log indicates that all peers inside SelectedProfileName:CHF-OFF are dead.

The log covers all endpoints configured on SMF, and anytime you see all peers are dead inside the profile this always leads to session impact.

master-1 b26897bce81a[2516]: 
master-1 c77834f772f7[2516]: ************* TRANSACTION: 2475167152 *************
master-1 c77834f772f7[2516]: ************* TRANSACTION: 2475167152 *************
master-1 c77834f772f7[2516]: TRANSACTION SUCCESS:
master-1 c77834f772f7[2516]: TRANSACTION SUCCESS:
master-1 c77834f772f7[2516]: GR Instance ID : 1
master-1 c77834f772f7[2516]: GR Instance ID : 1
master-1 c77834f772f7[2516]: Txn Type : N40ChargingDataReq(3585)
master-1 c77834f772f7[2516]: Txn Type : N40ChargingDataReq(3585)
master-1 c77834f772f7[2516]: Priority : 1
master-1 c77834f772f7[2516]: Priority : 1
master-1 c77834f772f7[2516]: Session Namespace : smf(1)
master-1 c77834f772f7[2516]: Session Namespace : smf(1)
master-1 c77834f772f7[2516]: CDL Slice Name : smf
master-1 c77834f772f7[2516]: CDL Slice Name : smf
master-1 c77834f772f7[2516]: LOG MESSAGES:
master-1 c77834f772f7[2516]: LOG MESSAGES:
master-1 c77834f772f7[2516]: 2023/09/10 15:00:00.007 [ERROR] [nrfClient.Discovery.nrf] All Peers are Dead, Setting status code to 0 (timeout)
master-1 c77834f772f7[2516]: 2023/09/10 15:00:00.007 [ERROR] [nrfClient.Discovery.nrf] All Peers are Dead, Setting status code to 0 (timeout)
master-1 c77834f772f7[2516]: 2023/09/10 15:00:00.007 [ERROR] [nrfClient.Discovery.nrf] Message send failed, response [Type:CHF ServiceName:nchf-convergedcharging SelectedProfileName:"CHF-OFF" FailureProfile:"Fail-H-CHF-OFF" GroupID:"CHF-*" ]
master-1 c77834f772f7[2516]: 2023/09/10 15:00:00.007 [ERROR] [nrfClient.Discovery.nrf] Message send failed, response [Type:CHF ServiceName:nchf-convergedcharging SelectedProfileName:"CHF-OFF" FailureProfile:"Fail-H-CHF-OFF" GroupID:"CHF-*" ]
master-1 c77834f772f7[2516]: ***********************************************
master-1 c77834f772f7[2516]: ***********************************************

Based on the configuration, the SMF tries to reach to the primary server with higher priority in case there is an HTTP code 504 (timeout) system, and then the SMF tries to reach out to the secondary server. If that fails, as well in that case system also sets session in continue mode.

In the example, the secondary Charging function (CHF) for Offline is 10.10.10.2. The SMF received the 504 error and the action is FailureContinueAction.

master-2 42013075464a[2621]: 2023/09/10 15:00:00.063 rest-ep [ERROR] [RestClient.go:175] [infra.rest_client.core] Error in rest call err Post "http://10.10.10.2:1090/OFFLINE/nchf-convergedcharging/v2/chargingdata": context deadline exceeded
master-2 42013075464a[2621]: 2023/09/10 15:00:00.063 rest-ep [ERROR] [Config.go:1721] [nrfClient.Discovery.nrf] Send to NF rpcName[CHF], method:[DataRequest] EndPoint[http://10.10.10.2:1090/OFFLINE/nchf-convergedcharging/v2] failed
master-2 42013075464a[2621]: ************* TRANSACTION: 2252879781 *************
master-2 42013075464a[2621]: TRANSACTION SUCCESS:
master-2 42013075464a[2621]: GR Instance ID : 1
master-2 42013075464a[2621]: Txn Type : N40ChargingDataReq(3521)
master-2 42013075464a[2621]: Priority : 1
master-2 42013075464a[2621]: Session Namespace : smf(1)
master-2 42013075464a[2621]: CDL Slice Name : smf
master-2 42013075464a[2621]: LOG MESSAGES:
master-2 42013075464a[2621]: 2023/09/10 15:00:00.063 [ERROR] [rest_ep.app.ChargingIntf] {imsi-1234567891011121:21} Received Charging Data Response error with timediff 10001557123 - Request message {{"invocationSequenceNumber":1,"invocationTimeStamp":"2025-11-10T14:29:29Z","nfConsumerIdentification":{"nFIPv4Address":"10.10.10.12","nFName":"dce0c1d7-aa37-4f2c-870b-6f7c1be10af1","nFPLMNID":{"mcc":"123","mnc":"456"},"nodeFunctionality":"SMF"},"notifyUri":"http://10.10.10.12:8195/callbacks/v2/notifyUri/1909959397/chargingNotification","pDUSessionChargingInformation":{"chargingId":1909959397,"pduSessionInformation":{"authorizedQoSInformation":{"5qi":1,"arp":{"preemptCap":"NOT_PREEMPT","preemptVuln":"PREEMPTABLE","priorityLevel":1}},"authorizedSessionAMBR":{"downlink":"2048000 bps","uplink":"2048000 bps"},"chargingCharacteristicsSelectionMode":"VISITING_DEFAULT","dnnId":"data","hPlmnId":{"mcc":"123","mnc":"456"},"networkSlicingInfo":{"sNSSAI":{"sst":1}},"pduAddress":{"iPv6dynamicPrefixFlag":true,"pduIPv6AddresswithPrefix":"x:x:x:x::"},"pduSessionID":21,"pduType":"IPV6","ratType":"WLAN","servingCNPlmnId":{"mcc":"123","mnc":"456"},"sscMode":"SSC_MODE_1","startTime":"2025-11-10T14:29:29Z"},"userInformation":{"roamerInOut":"IN_BOUND","servedGPSI":"msisdn-12345678901"},"userLocationinfo":{"n3gaLocation":{"portNumber":4505,"ueIpv4Addr":"x.x.x.x"}}},"subscriberIdentifier":{"subscriberIdentityType":"SUPI","supi":"imsi-1234567891011121"}}} 
master-2 42013075464a[2621]: 2023/09/10 15:00:00.063 [ERROR] [nrfClient.SendMesg.NRF] FHI status 504 timediff 1000332537, Uri: http://10.10.10.2:1090/OFFLINE/nchf-convergedcharging/v2, retryCount = 0 loopMaxRetry = 0, maxRetry = 0 
master-2 42013075464a[2621]: 2023/09/10 15:00:00.063 [ERROR] [nrfClient.Discovery.nrf] Message send failed, response [Type:CHF Http2_Status:504 FailAction:FailureContinueAction MsgType:3587 ServiceName:nchf-convergedcharging SelectedProfileName:"CHF-OFF" FailureProfile:"Fail-H-CHF-OFF" GroupID:"CHF-*" ]
master-2 42013075464a[2621]: ***********************************************

SMF Checks

On SMF, check peers and their connected time regarding the endpoint that reported the issue.

smf# show peers    
GR                                                                                POD              CONNECTED              ADDITIONAL                          
INSTANCE  ENDPOINT        LOCAL ADDRESS         PEER ADDRESS           DIRECTION  INSTANCE   TYPE  TIME           RPC     DETAILS     INTERFACE NAME     VRF  
--------------------------------------------------------------------------------------------------------------------------------------------------------------
1         <none>          192.168.1.1       	10.10.10.2:1090      Outbound   rest-ep-0  Rest  4 hours        CHF     <none>      n40                NA   
1         <none>          192.168.1.2       	10.10.10.2:1090      Outbound   rest-ep-1  Rest  4 hours        CHF     <none>      n40                NA   
1         <none>          192.168.1.3       	10.10.10.1:1090     Outbound   rest-ep-2  Rest  4 hours        CHF     <none>      n40                NA   
1         <none>          192.168.1.3       	10.10.10.2:1090      Outbound   rest-ep-2  Rest  4 hours        CHF     <none>      n40                NA   
1         <none>          192.168.1.4       	10.10.10.1:1090     Outbound   rest-ep-3  Rest  4 hours        CHF     <none>      n40                NA
1         <none>          192.168.1.2       	10.10.10.1:1090     Outbound   rest-ep-1  Rest  4 hours        CHF     <none>      n40                NA   
1         <none>          192.168.1.4       	10.10.10.2:1090      Outbound   rest-ep-3  Rest  2 hours        CHF     <none>      n40                NA   
1         <none>          192.168.1.1       	10.10.10.1:1090     Outbound   rest-ep-0  Rest  4 hours        CHF     <none>      n40                NA    

// CHF related profiles

profile network-element chf CHF-OFFLINE
 nf-client-profile        CHF-OFF
 failure-handling-profile Fail-H-CHF-OFF
 discovery local
exit

// Here is configuration for CHF profile where all peers are dead

profile nf-client nf-type chf
 chf-profile CHF-OFF
  locality LOC1
   priority 1
   service name type nchf-convergedcharging
    responsetimeout 1000
    endpoint-profile epprof
     capacity   10
     api-root   OFFLINE
     uri-scheme http
     version
      uri-version v2
      exit
     exit
     endpoint-name ep1
      priority 1
      capacity 10
      primary ip-address ipv4 10.10.10.1
      primary ip-address port 1090
     exit
     endpoint-name ep2
      priority 2
      capacity 10
      primary ip-address ipv4 10.10.10.2
      primary ip-address port 1090
     exit
    exit
   exit
  exit
 exit

// Failure handling that in case of timeout (HTTP code 504) then try secondary server one time and then proceed with continuing the session

profile nf-client-failure nf-type chf
 profile failure-handling Fail-H-CHF-OFF
  service name type nchf-convergedcharging
   responsetimeout 1000
   message type ChfConvergedchargingCreate
    status-code httpv2 504
     retry  1
     action continue
    exit
   exit
   message type ChfConvergedchargingUpdate
    status-code httpv2 504
     retry  1
     action continue
    exit
   exit
   message type ChfConvergedchargingDelete
    status-code httpv2 504
     retry  1
     action continue
    exit
   exit
  exit

Grafana Checks

The direct correlation between HTTP 504 Timeout and the time of the issue was observed.

query: sum(increase(smf_restep_http_msg_total{nf_type="chf", namespace=~"$namespace"}[15m])) by (api_name, response_cause, response_status)

Nexus Checks

Check for any flaps that happened.

Nexus# show logging last 500 | include BFD

Solution

The solution to this problem varies in this case because SMF is the client and CHF is the server.

Loss of connection was not caused by SMF.