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  1. Core Server
  2. SERVER-6595

Improvement and clarification of errors/warnings that can arise when starting Enterprise Mongod with SNMP enabled

    • Type: Icon: Improvement Improvement
    • Resolution: Incomplete
    • Priority: Icon: Major - P3 Major - P3
    • None
    • Affects Version/s: None
    • Component/s: Admin, Networking
    • Labels:
      None
    • Environment:
      Any Supported O/S (i.e. variant of Linux) for Enterprise MongoDB -

      $ mongod --version
      db version v2.0.6, pdfile version 4.5
      Wed Jul 25 11:06:40 git version: e1c0cbc25863f6356aa4e31375add7bb49fb05bc modules: subscription

      The first two issues receive the same error in the logs but have a different cause whilst the third issue does not generate any information in the log file.

      Resolution of these issue will aide troubleshooting of problem with starting Enterprise mongod with SNMP enabled.

      Issue 1 - Start MongoD Enterprise without /etc/snmp/mongod.conf

      Check for files -

      $ ls /etc/snmp/mongo*
      ls: cannot access /etc/snmp/mongo*: No such file or directory
      
      $ ls /usr/share/snmp/mibs/MONGO*
      /usr/share/snmp/mibs/MONGO-MIB.txt
      

      Start mongod with snmp -

      $ mongod  --snmp-master --fork --logpath /var/tmp/snmp-master.log
      $ forked process: 6895
      all output going to: /var/tmp/snmp-master.log
      

      mongod does not start and "master err:1" error appears in the log file -

      $ egrep -i 'snmp|mib' /var/tmp/snmp-master.log
      Wed Jul 25 10:06:20 [initandlisten] options: { fork: true, logpath: "/var/tmp/snmp-master.log", snmp-master: true }
      Wed Jul 25 10:06:20 [SNMPAgent] warning: error starting SNMPAgent as master err:1
      
      $ sudo lsof -i :1161
      $
      

      Issue 2

      Check for files -

      $ ls -la /etc/snmp/mongod.conf 
      -rw-r--r--. 1 root root 1392 Jul  3 15:18 /etc/snmp/mongod.conf
      
      $ ls -la /usr/share/snmp/mibs/MONGO-MIB.txt 
      -rw-r--r--. 1 root root 3658 Jul  3 14:57 /usr/share/snmp/mibs/MONGO-MIB.txt
      

      Start netcat on udp port 1161 -

      $ nc -l -u 1161 &
      [1] 7461
      
      $ sudo lsof -i :1161
      COMMAND  PID     USER   FD   TYPE DEVICE SIZE/OFF NODE NAME
      nc      7461 sysadmin    3u  IPv4  35755      0t0  UDP *:health-polling 
      

      Start mongod with snmp -

      $ mongod  --snmp-master --fork --logpath /var/tmp/snmp-master.log
      $ forked process: 7468
      all output going to: /var/tmp/snmp-master.log
      

      and we are able to generate the same error as in the previous issue, however, the cause is different as the socket is not free -

      $ egrep -i 'snmp|mib' /var/tmp/snmp-master.log 
      Wed Jul 25 11:47:31 [initandlisten] options: { fork: true, logpath: "/var/tmp/snmp-master.log", snmp-master: true }
      Wed Jul 25 11:47:32 [SNMPAgent] warning: error starting SNMPAgent as master err:1
      
      $ sudo lsof -i :1161
      COMMAND  PID     USER   FD   TYPE DEVICE SIZE/OFF NODE NAME
      nc      7461 sysadmin    3u  IPv4  35755      0t0  UDP *:health-polling 
      

      Issue 3

      On this occasion no MIB file is present, however, no warning/notification is generated. This is not ideal for troubleshooting -

      Check for files -

      $ ls -la /usr/share/snmp/mibs/MONGO-MIB.txt 
      ls: cannot access /usr/share/snmp/mibs/MONGO-MIB.txt: No such file or directory
      
      $ ls -la /etc/snmp/mongod.conf 
      -rw-r--r--. 1 root root 1392 Jul  3 15:18 /etc/snmp/mongod.conf
      

      Start mongod with SNMP -

      $ mongod --snmp-master --dbpath /data/db/master/ --port 3001 --fork --logpath /var/tmp/snmp-master.log
      $ forked process: 7210
      all output going to: /var/tmp/master/1.log
      

      The log file shows that the service starts cleanly but there is no warning about a missing MIB file -

      $ egrep -i 'snmp|mib' /var/tmp/snmp-master.log 
      Wed Jul 25 11:22:01 [initandlisten] options: { dbpath: "/data/db/master/", fork: true, logpath: "/var/tmp/master/1.log", port: 3001, snmp-master: true }
      Wed Jul 25 11:22:01 [SNMPAgent] SNMPAgent running as master
      
      $ sudo lsof -i :1161
      [sudo] password for sysadmin: 
      COMMAND  PID     USER   FD   TYPE DEVICE SIZE/OFF NODE NAME
      mongod 7210 sysadmin    9u  IPv4  33996      0t0  UDP localhost:health-polling
      

            Assignee:
            mark Mark porter
            Reporter:
            mark Mark porter
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              Created:
              Updated:
              Resolved: