jmxsh

I recently discovered jmxsh, which provides TCL scripting facilities to interact with JMX. Its pretty impressive when compared to something like jconsole. For instance, I was able to write the following little script to query HornetQ for the amount of messages on a queue:

set host  [lindex $argv 0]
set port  [lindex $argv 1]
set queue [lindex $argv 2]

jmx_connect -h $host -p $port
set message_count [jmx_get  -m org.hornetq:module=JMS,name="$queue",type=Queue MessageCount]

puts "$message_count"

jmx_close

I can then run the script like this and it prints the amount of messages on the DLQ to stdout:

./jmxsh queue_count.tcl localhost 3000 DLQ

While the use of TCL might seem obtuse (ie, why not Groovy?), it makes sense from the standpoint of a sysadmin. The JMX agnostic language allows them to script against an app's MBeans with minimal exposure to Java or the JMX API's.