Jcrontab / Discussion / Open Discussion: Couple of fixes

Hello, we encountered a couple of issues and fixed them. If it would help to have these fixes, please let me know (although source sync might pose a problem!)

Regards,
Keith

Running environment:
~~~~~~~~~~~~~~~~~~~~

VM: Sun JDK1.4.0
Container: Tomcat 4.0.2

Development platform(s): Win32 (XP Pro)
Tested on: NT4 (SP3), XP Pro
Tests pending for: Solaris 2.6

Issues:
~~~~~~~

1. Temination of application slow.
Observation: At times, caused container to wait till application terminated.

   Comments:    Even after the container had called "destroy" for all servlets,
                jcrontab did not complete all threads causing container to wait.
                The destroy method of the servlet 'loadCrontabServlet' is called
                and then the application waits for threads to join. This code
                is seen in org.jcrontab.Crontab.unint(..)

   Fixes:       1) Servlet 'destroy' method added to org.jcrontab.loadCrontabServlet.
                   This simply calls the unint method of Crontab. The shutdown
                   hook is still left as is to ensure 100% cleanup is achieved
                   but would not necessarily do anything useful now.

                2) Crontab.unint(..) modified to make sure waiting threads are
                   interrupted. Each task (org.jcrontab.CronTask) is interrupted
                   before the calling join(..).
                   Once all tasks are "joined" with, the actual cron scheduler
                   (org.jcrontab.Cron) is interrupted as well in case it is
                   sleeping/waiting to generate cron events.
                   The above interrupting of threads ensures that joining times
                   are minimised. Downside is that any running tasks could well
                   be interrupted in the middle and cleanup/wrap-up may not be
                   acheived.

                3) Modified methods waitNextMinute() and generateEvents()
                   of org.jcrontab.Cron. Both methods now check whether they
                   thread needs to be run or not. This is already determined by
                   shouldRun field (private field). Therefore Cron now makes
                   sure that if the entire application needs termination, it
                   does not generate any events (which now make no sense to do
                   as everything is coming to an end) or wait for any longer
                   time (as it makes sense for everything to finish up as soon
                   as possible as the container/application is dying).

Status: Fixed requirement.

Todo: a) Investigate is wrap ups, etc of running tasks can be adversely
affected in CronTask.

2. Emailing of a process report is buggy.
   Observation: A) Once an email is sent for the first time, any output to the console
                   goes away.
                B) Path for temp file creation not correct
                C) Temp files created are not cleaned up
                D) Output generated outside a given process ends up in an email
                E) Process errors (written to err stream) not in email
                F) Sending mail fails as cannot get properties

   Comments:    i) PrintStream redirection/cleaup issues are the cause.
                ii) Path for the temp files within application or container not
                    either specified or not right
                iii) Perhaps temp file not closed that could lead to problems as well?

   Fixes:       1) Issue 2.B was solved by finding out the path which was expected.
                   This turned out to be by default "temp" directory sitting off
                   the container's root dir. This will be platform dependent more
                   than likely. On NT/XP, fixed by creating a folder "temp" sitting
                   off the container's home. Note: This temp dir can also be
                   specified in the container's config.
                2) Issues A, C, D and E were solved by doing the following in the
                   run() method of org.jcrontab.CronTask:
                   - storing away the original out and err streams so that upon
                     completion of the task at hand, they can be restored;
                   - Out and Err streams are directed to the temp file;
                   - Closing the temp file (java.io.FileOutputStream.close method);
                   - Restoring out and err streams to the original ones. A finally
                     block is added that also does this in case an exception was
                     raised somewhere else.
                3) Issue F fixed by a simple case of ensuring correct character
                   capitalisation in the code. Now looks for org.jcrontab.SendMail.from
                   rather than org.jcrontab.sendMail.from to follow with other
                   property naming conventions in the properties file.

Status: Fixed bugs.

Todo: Document in (1) the config param that can be set to ensure temp dir
problems cannot occur.

Suggestions
~~~~~~~~~~~

1) Rather that config files, etc being in org.jcrontab.data folder, why not keep them
in WEB-INF/etc. For UNIX based people, this would be the first place they'll look.

Status: Done. Application (servlet) config in web.xml specifies required directory.

Couple of fixes - container shutdown, emails

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Couple of fixes - container shutdown, emails

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Couple of fixes - container shutdown, emails