FAQ for diagnostic commands in Open Message Queue Cannot resolve external resource into attachment.

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• • What are the commands?*

    imqbrokerd - starts the broker
       imqadmin - starts a gui based admin tool (minimal functionality)
       imqdbmgr - used to set of the database
       imqcmd - primary admin tool (cheat you can use -pw instead of a passfile)
       imqobjmgr - used to set of the connection factory
       imqusermgr - manages the file based password directory

• • What are the arguments for each of these commands?*
  • All the commands will display their arguments if you invoke them with -help. You can also read the Command Line Reference chapter of the Administration Guide. (this link is for MQ 4.1)

• • Where are the log files?*
  • That depends on how it is installed and the name of the broker (usually imqbrokerd although that may change based on user or with the application server)
    • On Solaris (and Linux in a slightly different location) with a package based install it is in

      /var/imq/instances/<brokername>/logs

    • On Windows and with file based installs, it is in the var directory where mq is installed. e.g.

      <mq install>/var/instances/imqbrokerd/logs

• • How do I get command line arguments to the broker when I'm running with the GlassFish Application Server?*
  • Run in LOCAL mode and pass the arguments and configure the arguments in GlassFish
  • Run as REMOTE and start the broker with the arguments you want (before starting GlassFish)
  • See the GlassFish MQ Configuration Options page for details about Local and Remote

• • Where do I set the configuration options in Open MQ?*
  • MQ has configuration settings for both the client and for the broker.
  • On the client you can either:
    • create and set connection factory object using imqobjmgr
    • pass arguments in on the command line
  • On the broker, we have two types of data:
    • operational objects (e.g. destinations) which are created with imqcmd
    • configuration which is set in the config.properties file (and in some cases can also be set by imqcmd).
      • you can also pass those properties in with -D e.g.

        imqbrokerd -tty -Dmyprop=myvalue

    • config.properties is located in:

      var/instances/<brokername>/config

• How can I check to see that the broker is really running?
  • Use telnet to check the portmapper port:

    telnet localhost 7676

• How do I get more logging on the broker?
  • You can change the log level in the config.properties file OR use the loglevel command line argument (e.g.

    imqbrokerd -loglevel DEBUG

    ). The MQ broker supports several different log levels, the most commonly used ones are:

    ERROR
           WARNING
           INFO
           DEBUG

• How do I get information to show up in the window I start the broker?
  • You can set this up in config.properties
  • You can use the -tty option to start the broker

• • I keep seeing entries in the log like RED, ORANGE, YELLOW, GREEN in the log file, what does this mean?*
  • MQ has memory management. As the server gets low on memory producers are throttled back to attempt to keep the broker running.

• • How do I start a standard cluster of broker nodes?*
    This is described in the product manuals and also the on-line training, but the simplest way is to use the -cluster property on imqbrokerd. e.g.

    imqbrokerd -tty -cluster whippet:7676,whippet:7777
        imqbrokerd -tty -port 7777 -cluster whippet:7676,whippet:7777

• • How can I pass vm arguments (like -Xmx) into the broker?*
  • Use -vmarg, e.g.

    imqcmd -vmargs -Xmx=2G

• • I look in the code and I see "public" and "private" properties for the broker. What is this for?*
  • MQ property based configuration is broken up into three categories:
    • public (in the docs and supported)
    • private (not supported documented in an installed file called default.properties)
    • secret - hidden in various spots of the code
  • default.properties is in the lib directory in a file-based install

• • How can I see the protocol that is passing between the client/broker or brokers?*
  • On the client, you can turn on protocol level debugging with:

    -Dimq.debug -DReadOnlyPacket -DReadWritePacket

  • On the broker, you can use the private -debug command line argument (protocol is dumped to the log file). e.g.

    imqbrokerd -debug pkt

  • Options are:

pkt - all client/broker communication
   pktin - incoming client/broker communication
   pktout - outgoing client/broker communication
   cluster - all cluster communication
   lock - only cluster locking communication
   clscon - only cluster connection information
   clstxn - only cluster-wide transaction processing info
   clsmsg - protocol in the cluster
   clsha - only HA information

• • How can I read this protocol output?*
  • Send us e-mail to users@mq.java.net. We'll talk you through this. (It's a bit more complex than can be managed here in this FAQ)

• • The system is behaving weirdly, what can I do?*
  • Open MQ has a secret dump command which can be used to retrieve the state of most of the system (although its difficult to read). It is not documented, but generally looks something like:

    imqcmd dump bkr -debug -o file=/tmp/bkr.log

• • How do I read this dump file?*
  • Drop us a line users@mq.java.net. We'll talk you through this. (It's a bit more complex than can be managed here in this FAQ)

• • How can I get a stack trace with imqdbmgr command?*
  • Invoke imqdbmgr command with -debug option.

• • How do I know if brokers in Open MQ cluster are really communicating ?*
  • Open MQ has private imqcmd command line options which can be used to dynamically (only supported for Open MQ version >= 4.4u1) turn on/off the Open MQ cluster private debug property imq.cluster.debug.ping, like imqcmd update bkr -o imq.cluster.debug.ping=true -debug -nocheck, on each broker in the cluster, then you should see periodic ping packet dumps in the broker log like following. Alternatively you can also dynamically (only supported for Open MQ version >= 4.4u1) turn on/off the Open MQ cluster private debug property imq.cluster.debug.packet to see all packet dumps between brokers.

[......] SENDING PACKET : mq://...... <---> mq://......
Packet =     Packet: 33
......

[......] RECEIVING PACKET : mq://...... <---> mq://......
Packet =     Packet: 33
......