Mailing-List: contact issues-help@commons.apache.org; run by ezmlm
Precedence: bulk
Reply-To: issues@commons.apache.org
Date: Wed, 13 Mar 2013 21:10:13 +0000 (UTC)
From: "Oliver Heger (JIRA)" <jira@apache.org>
To: issues@commons.apache.org
Message-ID: <JIRA.12636664.1363123910190.436506.1363209013450@arcas>
In-Reply-To: <JIRA.12636664.1363123910190@arcas>
References: <JIRA.12636664.1363123910190@arcas>
Subject: [jira] [Commented] (CONFIGURATION-532) FileChangedReloadingStrategy
 should support reloading of rolled-back (older timestamp) files
MIME-Version: 1.0
Content-Type: text/plain; charset=utf-8
Content-Transfer-Encoding: 7bit


    [ https://issues.apache.org/jira/browse/CONFIGURATION-532?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=13601640#comment-13601640 ] 

Oliver Heger commented on CONFIGURATION-532:
--------------------------------------------

Your request perfectly makes sense to me. The documentation of {{FileChangedReloadingStrategy}} says
{quote}
A reloading strategy that will reload the configuration every time its underlying file is changed.
{quote}
So one could argue that the current behavior to detect only newer files is actually a bug. I think when the class was created the author had the assumption that somehow modifying the configuration file would always result in a newer timestamp which is obviously not the case.

So shouldn't we in general use a != comparison?
                
> FileChangedReloadingStrategy should support reloading of rolled-back (older timestamp) files
> --------------------------------------------------------------------------------------------
>
>                 Key: CONFIGURATION-532
>                 URL: https://issues.apache.org/jira/browse/CONFIGURATION-532
>             Project: Commons Configuration
>          Issue Type: Improvement
>          Components: File reloading
>    Affects Versions: 1.9
>            Reporter: Mike Lucas
>   Original Estimate: 48h
>  Remaining Estimate: 48h
>
> Currently the {{FileChangedReloadingStrategy}} only reloads when the timestamp of the file on the filesystem is _newer_ than the timestamp it had when it was last loaded.
> This may not be the expected behaviour when, for example, an administrator makes a backup copy of the original configuration file before making changes. If the administrator wants to roll back to the original configuration, he may expect that copying/renaming the backup back to the original name, would cause the original configuration to take effect again.
> Another example where the current behaviour is problematic is when using a Deploy System (like we do at my company). We expect to be able to roll-back to a previous configuration by simply redeploying the Config artifact, but because the timestamps reflect when the Config artifact was _built_ (not when it was deployed), this roll-back will not work.
> The current behaviour could be kept as the default, simply adding {{setReloadOnRollback()}} or similarly named method to change the behaviour to reload when the timestamp is either older or newer (i.e. not equal to) the {{lastModified}} variable. Another option would to be to create subclass {{FileChangedOrRolledBackReloadingStrategy}} that overrides the {{hasChanged()}} method.
> In either option the actual change is to use {{!=}} instead of {{>}} in the {{hasChanged}} method's comparison:
> {code}
> return file.lastModified() > lastModified;
> {code}

--
This message is automatically generated by JIRA.
If you think it was sent incorrectly, please contact your JIRA administrators
For more information on JIRA, see: http://www.atlassian.com/software/jira