Mailing-List: contact issues-help@commons.apache.org; run by ezmlm
Precedence: bulk
Reply-To: issues@commons.apache.org
Date: Wed, 17 Apr 2013 06:55:17 +0000 (UTC)
From: "Richard Hawkes (JIRA)" <jira@apache.org>
To: issues@commons.apache.org
Message-ID: <JIRA.12514326.1310827054130.178931.1366181717807@arcas>
In-Reply-To: <JIRA.12514326.1310827054130@arcas>
References: <JIRA.12514326.1310827054130@arcas>
Subject: [jira] [Commented] (IO-279) Tailer erroneously considers file as
 new
MIME-Version: 1.0
Content-Type: text/plain; charset=utf-8
Content-Transfer-Encoding: 7bit


    [ https://issues.apache.org/jira/browse/IO-279?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=13633836#comment-13633836 ] 

Richard Hawkes commented on IO-279:
-----------------------------------

Strikes me that this should simply be re-opened. Issue is recreatable, but as yet no fix is known.
                
> Tailer erroneously considers file as new
> ----------------------------------------
>
>                 Key: IO-279
>                 URL: https://issues.apache.org/jira/browse/IO-279
>             Project: Commons IO
>          Issue Type: Bug
>    Affects Versions: 2.0.1
>            Reporter: Sergio Bossa
>             Fix For: 2.4
>
>         Attachments: IO-279.patch
>
>
> Tailer sometimes erroneously considers the tailed file as new, forcing a repositioning at the start of the file: I'm still unable to reproduce this in a test case, because it only happens to me with huge log files during Apache Tomcat startup.
> This is the piece of code causing the problem:
> {code}
> // See if the file needs to be read again
> if (length > position) {
>     // The file has more content than it did last time
>     last = System.currentTimeMillis();
>     position = readLines(reader);
> } else if (FileUtils.isFileNewer(file, last)) {
>     /* This can happen if the file is truncated or overwritten
>         * with the exact same length of information. In cases like
>         * this, the file position needs to be reset
>         */
>     position = 0;
>     reader.seek(position); // cannot be null here
>     // Now we can read new lines
>     last = System.currentTimeMillis();
>     position = readLines(reader);
> }
> {code}
> What probably happens is that the new file content is about to be written on disk, the date is already updated but content is still not flushed, so actual length is untouched and there you go.
> In other words, I think there should be some better method to verify the condition above, rather than relying only on dates: keeping and comparing the hash code of the latest line may be a solution, but may hurt performances ... other ideas?

--
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