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  1. Core Server
  2. SERVER-26575

Unable to start mongod service when omiting pidfilepath in mongod.conf

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Details

    • Bug
    • Status: Closed
    • Major - P3
    • Resolution: Fixed
    • 3.2.10
    • 3.4.0-rc1
    • Packaging
    • Fully Compatible
    • ALL
    • v3.2
    • Hide

      1. Populate a file named test.conf with yaml that does not contain a reference to pidfilepath:

      > cat test.conf
      		 
      storage:
      		 
          dbPath: /mnt/data/mongo3
      		 
          directoryPerDB: true
      		 
          engine: wiredTiger
      		 
          journal:
      		 
              enabled: true
      		 
       
      		 
      systemLog:
      		 
          logAppend: true
      		 
          quiet: false
      		 
          destination: syslog
      		 
       
      		 
      processManagement:
      		 
          fork: true
      		 
       
      		 
      security:
      		 
          keyFile: /etc/mongo.key
      		 
       
      		 
      replication:
      		 
          replSetName: testrepl
      		 
       
      		 
      setParameter:
      		 
          logUserIds: 1

      2. Set the config file

      > CONFIGFILE="test.conf"

      3. Parse the pidfilepath

      > PIDFILEPATH=`awk -F'[:=]' -v IGNORECASE=1 '/^[[:blank:]]*(processManagement\.)?pidfilepath[[:blank:]]*[:=][[:blank:]]*/{print $2}' "$CONFIGFILE" | tr -d "[:blank:]\"'" | awk -F'#' '{print $1}'`

      4. Run the check

      if [ -f $PIDFILEPATH ]; 
           then echo "Error starting mongod. $PIDFILEPATH exists." 
           RETVAL=1 
           return 
      fi

      5. Observe that the statement erroneously evaluates to true.

      Show
      1. Populate a file named test.conf with yaml that does not contain a reference to pidfilepath: > cat test.conf storage: dbPath: /mnt/data/mongo3 directoryPerDB: true engine: wiredTiger journal: enabled: true   systemLog: logAppend: true quiet: false destination: syslog   processManagement: fork: true   security: keyFile: /etc/mongo.key   replication: replSetName: testrepl   setParameter: logUserIds: 1 2. Set the config file > CONFIGFILE="test.conf" 3. Parse the pidfilepath > PIDFILEPATH=`awk -F'[:=]' -v IGNORECASE=1 '/^[[:blank:]]*(processManagement\.)?pidfilepath[[:blank:]]*[:=][[:blank:]]*/{print $2}' "$CONFIGFILE" | tr -d "[:blank:]\"'" | awk -F'#' '{print $1}'` 4. Run the check if [ -f $PIDFILEPATH ]; then echo "Error starting mongod. $PIDFILEPATH exists." RETVAL=1 return fi 5. Observe that the statement erroneously evaluates to true.
    • Build 2016-10-31

    Description

      File: init.d-mongod

      The problem occurs when the contents of the $CONFIGFILE does not contain a reference to pidfilepath. In this case, the parsing results in a null string value for PIDFILEPATH. The if-statement that uses PIDFILEPATH does not quote the variable and so the if-statement will evaluate to true even though there is obviously no such 'null' file.

      This was observed when running 

      service mongod start

      resulting in the error

      Error starting mongod.  exists.

      Surrounding the PIDFILEPATH in quotes should fix the problem:

      if [ -f "$PIDFILEPATH" ];
      then echo "Error starting mongod. $PIDFILEPATH exists."
      RETVAL=1
      return
      fi

      The documentation states that the pidfilepath is not required: "Without a specified processManagement.pidFilePath option, the process creates no PID file."

      Appears to be resulting from the changes made in SERVER-12048

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        Issue Links

          related to

          Bug - A problem which impairs or prevents the functions of the product. SERVER-12048 Calling "service mongod start" with mongod running prevents "service mongod stop" from working

          • Major - P3 - Major loss of function.
          • Closed

          Activity

            People

              brian.samek@mongodb.com Brian Samek
              hpatel001 Harsh Patel
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                Created:
                Updated:
                Resolved: