Multicasting Issues

  • So we are trying to do a multicast deployment. The task is started, and the clients are booted. All the clients eventually show a progress screen of stars:

                  • … ad. infinitum …

    The server logs the same message over and over:

    Checking if I am the group manager
    I am the group manager

    And that’s it. These machines are all on the same VLAN, and multicasting is enabled on the switch. Yet nothing happens :(
    Our network admin has seen the clients connect to the mcast group - yet the server never picks up any of these clients … so where do I start looking. We are using alcatel switches …

  • I found another post from another site…can’t find it now to save my life…but it suggested that you go to /etc/hosts and edit the IP
    addresses from to whatever it was that you set as your IP address for the server. I changed them both and it worked like a charm. If I come across that post again I’ll add it in.

  • Developer

    Please, Todd, paste your mc_checkin.php code. I try to know where is the problem.

  • I have the same problem. MadX, did you get resolution from Fernando’s posts?

  • Developer


    I have located where is the problem. When the client runs the fog script, this script call to a web service: mc_checkin.php
    [CODE]fog: line 108

    echo -n " * Checking In…";
    queueinfo=wget -q -O - "http://${web}service/mc_checkin.php?mac=$mac" 2>/dev/null
    echo “Done”;
    while [ “$queueinfo” != “##” ]
    echo -n " * $queueinfo ";
    queueinfo=wget -q -O - "http://${web}service/mc_checkin.php?mac=$mac" 2>/dev/null
    sleep 5;

    In the line 110 calls to the web service:
    [I]queueinfo=wget -q -O - "[url]http://${web}service/mc_checkin.php?mac=$mac[/url]" 2>/dev/null[/I]
    Print “Done” in the screen, but queueinfo variable is empty. This is the problem.

    The mc_checkin.php web service doesn’t work fine. Put checkpoints in the code using “echo” to see where is the problem.
    The mc_checkin.php is in /var/www/fog/service directory

  • [ATTACH=full]44[/ATTACH]
    Okay, we have now set up the server and 3 clients in a controlled environment.
    They all get their images - and boot into the FOG kernel.
    The Screen gets to this point - ie: no “Please Wait” screen


  • The FOGMulticastManager is on - and logs every 10 seconds (Checking if I am the group Manager …)
    (checked with ps aux |grep Multicast)
    There is logging going on
    The udp sender command is being executed (see the udp-sender gzip -d …)
    The clients don’t ‘crash’ - they boot into their kernels and the stars appear.

    What I am planning on doing in the morning is connecting 5-6 clients on a dumb switch (ie: take vlan out the picture) We are currently running alcatel switches and all the clients are on the same switch - but are VLAN tagged. I will report the results

  • Developer

    Obviously if you make unicast tasks, the kernel shouldn’t be the problem.
    I use fog 0.30, probably fog .032 or your version works in the same way.
    Life cycle of a multicast task (short version ;) ):
    []You ask to the server to do a multicast tasks (in the web interface)
    ]In the fog database:
    []tasks table: one registry per client. tasksType=C, taskState=0
    ]MulticastSession: one registry. msSTate=0
    []MulticastSessionAssoc: this table links one MulticastSession with “M” client tasks. (1:M relation)
    ]FOGMulticastManager service. This service makes a query, every 5 seconds, to know if there are new multicast tasks. (you can see the FOGMulticastManager log in /opt/fog/log/multicast.log). If the tasks is new:
    []Update the MulticastSession.msState=1
    ]Create a udp-sender command (see the multicast.log). Create a multicast session in the server.
    []Send a WOL to the clients
    ]The client is awake
    []The client connects with the PXE server
    ]the client downloads the kernel
    []the client loads the kernel
    ]the client downloads the init.gz file
    []the client loads the init.gz file
    ]the client runs “fog” script. This script is in /bin
    []the script checks some parameters: OS, image file, …
    ]The client update DB, via webservice, and tasks.taskState=1
    []the script mount the /images directory in the server
    ]the script makes some thigs more
    []the script runs udp-receiver command
    ]Blue screen “Please Wait”
    []All clients links with the multicast session. The download process begins.
    ]The download process ends.
    []The client updates DB, via webservice, and tasks.taskState=2
    ]FOGMulticastManager service updates the DB, and now multicastSession.msState=2
    []Multicast task ends
    some questions:
    ]Is FOGMulticastManager ON?
    []FOGMulticastManager log?
    ]The udp-sender command, is running?
    [*]When crashs the client?

  • Yep … works a charm … obviously when doing 40+ machines at a time - the speed slows to about 40MB / min. This is why we are trying to get multicasting working … Thanks for the replies so far :)

  • Developer

    and you can deploy the image using unicast?

  • Everything starts up fine :( That’s the strange part - other than a vesafb error - but that’s just graphics & has never interfered before …

  • Developer

    [quote=“MadX, post: 1345, member: 456”]

                  • … ad. infinitum …
                    And the previous messages??

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