The management operations may modify the model. When this occurs the xml backing the model is written out again reflecting the latest changes. In addition a full history of the file is maintained. The history of the file goes in a separate directory under the configuration directory.

As mentioned in Command line parameters#parameters the default configuration file can be selected using a command-line parameter. For a standalone server instance the history of the active standalone.xml is kept in jboss.server.config.dir/standalone_xml_history (See Command line parameters#standalone_system_properties for more details). For a domain the active domain.xml and host.xml histories are kept in jboss.domain.config.dir/domain_xml_history and jboss.domain.config.dir/host_xml_history.

The rest of this section will only discuss the history for standalone.xml. The concepts are exactly the same for domain.xml and host.xml.

Within standalone_xml_history itself following a successful first time boot we end up with three new files:

• standalone.initial.xml - This contains the original configuration that was used the first time we successfully booted. This file will never be overwritten. You may of course delete the history directory and any files in it at any stage.

• standalone.boot.xml - This contains the original configuration that was used for the last successful boot of the server. This gets overwritten every time we boot the server successfully.

• standalone.last.xml - At this stage the contents will be identical to standalone.boot.xml. This file gets overwritten each time the server successfully writes the configuration, if there was an unexpected failure writing the configuration this file is the last known successful write.

standalone_xml_history contains a directory called current which should be empty. Now if we execute a management operation that modifies the model, for example adding a new system property using the CLI:

[standalone@localhost:9990 /] /system-property=test:add(value="test123")
{"outcome" => "success"}

What happens is:

• The original configuration file is backed up to standalone_xml_history/current/standalone.v1.xml. The next change to the model would result in a file called standalone.v2.xml etc. The 100 most recent of these files are kept.

• The change is applied to the original configuration file

• The changed original configuration file is copied to standalone.last.xml

When restarting the server, any existing standalone_xml_history/current directory is moved to a new timestamped folder within the standalone_xml_history, and a new current folder is created. These timestamped folders are kept for 30 days.

[standalone@localhost:9990 /] :take-snapshot
{
    "outcome" => "success",
    "result" => {"name" => "/Users/kabir/wildfly/standalone/configuration/standalone_xml_history/snapshot/20110630-172258657standalone.xml"}
}

[standalone@localhost:9990 /] :list-snapshots
{
    "outcome" => "success",
    "result" => {
        "directory" => "/Users/kabir/wildfly/standalone/configuration/standalone_xml_history/snapshot",
        "names" => [
            "20110630-165714239standalone.xml",
            "20110630-165821795standalone.xml",
            "20110630-170113581standalone.xml",
            "20110630-171411463standalone.xml",
            "20110630-171908397standalone.xml",
            "20110630-172258657standalone.xml"
        ]
    }
}

[standalone@localhost:9990 /] :delete-snapshot(name="20110630-165714239standalone.xml")
{"outcome" => "success"}

[standalone@localhost:9990 /] :delete-snapshot(name="all")
{"outcome" => "success"}

[domain@localhost:9990 /] /host=master:list-snapshots
{
    "outcome" => "success",
    "result" => {
        "domain-results" => {"step-1" => {
            "directory" => "/Users/kabir/wildfly/domain/configuration/host_xml_history/snapshot",
            "names" => [
                "20110630-141129571host.xml",
                "20110630-172522225host.xml"
            ]
        }},
        "server-operations" => undefined
    }
}