• Use visualvm [1]
• JConsole [2]
• JDK Monitoring Tools [3]
• JDK Troubleshooting Tools [4]
• JDK Profiling Tools [5]

[1] http://docs.oracle.com/javase/6/docs/technotes/guides/visualvm/

[2] https://community.jboss.org/wiki/UsingJconsoleToConnectToJMXOnAS7

[3] http://docs.oracle.com/javase/6/docs/technotes/tools/#monitor

[4] http://docs.oracle.com/javase/6/docs/technotes/tools/#troubleshoot

[5] http://docs.oracle.com/javase/6/docs/technotes/tools/#monitor

Also jstat is a tool provided by the standard java installation to use via command line with a small footprint, so I've used it in production.

http://docs.oracle.com/javase/1.5.0/docs/tooldocs/share/jstat.html

The AS also exposes the standard platform mbean data via the CLI:

[standalone@localhost:9999 /] /core-service=platform-mbean/type=
class-loading      compilation        garbage-collector  memory             memory-manager     memory-pool        operating-system   runtime            threading          
[standalone@localhost:9999 /] /core-service=platform-mbean/type=memory-pool/name=
CMS_Old_Gen         CMS_Perm_Gen        Code_Cache          Par_Eden_Space      Par_Survivor_Space  
[standalone@localhost:9999 /] /core-service=platform-mbean/type=memory-pool/name=Par_Eden_Space:read-resource
{
    "outcome" => "success",
    "result" => {
        "name" => "Par_Eden_Space",
        "type" => "HEAP",
        "valid" => true,
        "memory-manager-names" => [
            "ConcurrentMarkSweep",
            "ParNew"
        ],
        "usage-threshold-supported" => false,
        "collection-usage-threshold-supported" => true,
        "usage-threshold" => undefined,
        "collection-usage-threshold" => 0L,
        "usage" => {
            "init" => 13500416L,
            "used" => 6431648L,
            "committed" => 13500416L,
            "max" => 26869760L
        },
        "peak-usage" => {
            "init" => 13500416L,
            "used" => 13500416L,
            "committed" => 13500416L,
            "max" => 26869760L
        },
        "usage-threshold-exceeded" => undefined,
        "usage-threshold-count" => undefined,
        "collection-usage-threshold-exceeded" => true,
        "collection-usage-threshold-count" => 0L,
        "collection-usage" => {
            "init" => 13500416L,
            "used" => 0L,
            "committed" => 13500416L,
            "max" => 26869760L
        }
    }
}

As a side note (recalling from other thread), was it the case that there is currently no CLI way of reading a specific value from a returned array? E.g the "peak-usage", "max" value? Outputted like that the peak-usage looks like sort of a map.