NAME

JMX::Jmx4Perl::Request - A jmx4perl request

SYNOPSIS

  $req = JMX::Jmx4Perl::Request->new(READ,$mbean,$attribute);

DESCRIPTION

A JMX::Jmx4Perl::Request encapsulates a request for various operational types.

The following attributes are available:

mbean

Name of the targetted mbean in its canonical format.

type

Type of request, which should be one of the constants

READ

Get the value of a attribute

WRITE

Write an attribute

EXEC

Execute an JMX operation

LIST

List all MBeans available

SEARCH

Search for MBeans

REGISTER_NOTIFICATION

Register for a JMX notification (not supported yet)

REMOVE_NOTIFICATION

Remove a JMX notification (not supported yet)

attribute

If type is READ or WRITE this specifies the requested attribute

value

For WRITE this specifies the value to set

arguments

List of arguments of EXEC operations

path

This optional parameter can be used to specify a nested value in an complex mbean attribute or nested return value from a JMX operation. For example, the MBean java.lang:type=Memory's attribute HeapMemoryUsage is a complex value, which looks in the JSON representation like

 "value":{"init":0,"max":518979584,"committed":41381888,"used":33442568}

So, to fetch the "used" value only, specify used as path within the request. You can access deeper nested values by building up a path with "/" as separator. This looks a bit like a simplified form of XPath.

max_depth, max_objects, max_list_size

With these number you can restrict the size of the JSON structure returned. max_depth gives the maximum nesting level of the JSON object,max_objects returns the maximum number of objects to be returned in total and max_list_size restrict the number of all arrays and collections (maps, lists) in the answer. Note, that you should use this restrictions if you are doing massive bulk operations.

target

If given, the request is processed by the agent in proxy mode, i.e. it will proxy to another server exposing via a JSR-160 connector. target is a hash which contains information how to reach the target service via the proxy. This hash knows the following keys:

url

JMX service URL as specified in JSR-160 pointing to the target server.

env

Further context information which is another hash.

METHODS

$req = new JMX::Jmx4Perl::Request(....);

 $req = new JMX::Jmx4Perl::Request(READ,$mbean,$attribute,$path, { ... options ... } );
 $req = new JMX::Jmx4Perl::Request(READ,{ mbean => $mbean,... });
 $req = new JMX::Jmx4Perl::Request({type => READ, mbean => $mbean, ... });

The constructor can be used in various way. In the simplest form, you provide the type as first argument and depending on the type one or more additional attributes which specify the request. The second form uses the type as first parameter and a hashref containing named parameter for the request parameters (for the names, see above). Finally you can specify the arguments completely as a hashref, using 'type' for the entry specifying the request type.

For the options max_depth, max_objects and max_list_size, you can mix them in into the hashref if using the hashed argument format. For the first format, these options are given as a final hashref.

If the request should be proxied through this request, a target configuration needs to be given as optional parameter. The target configuration consists of a JMX service url and a optional environment, which is given as a key-value map. For example

 $req = new JMX::Jmx4Perl::Request(..., { 
                                     target => { 
                                                  url => "",
                                                  env => { ..... }
                                                }
                                     } );

Note, depending on the type, some parameters are mandatory. The mandatory parameters and the order of the arguments for the constructor variant without named parameters are:

READ

 Order    : $mbean, $attribute, $path
 Mandatory: $mbean, $attribute

WRITE

 Order    : $mbean, $attribute, $value, $path
 Mandatory: $mbean, $attribute, $value

EXEC

 Order    : $mbean, $operation, $arg1, $arg2, ...
 Mandatory: $mbean, $operation

LIST

 Order    : $path

SEARCH

 Order    : $pattern
 Mandatory: $pattern

$request->get("type")

Get a request parameter

LICENSE

This file is part of jmx4perl.

Jmx4perl is free software: you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation, either version 2 of the License, or (at your option) any later version.

jmx4perl is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details.

You should have received a copy of the GNU General Public License along with jmx4perl. If not, see <http://www.gnu.org/licenses/>.

A commercial license is available as well. Please contact roland@cpan.org for further details.

AUTHOR

roland@cpan.org