Re: Curbing semaphore messages

 
From: "Chris Holt chris.holt@PROTECTED [Dada Mail Developers]" <dadadev@PROTECTED>
Subject: Re: Curbing semaphore messages
In-Reply-To: (no subject)
Date: November 5th 2019

Justin, Sorry for the delay in replying. No, the semaphore error message does not occur if the scheduled jobs are run from the admin page. As far as I could tell, no lock files were being written to .tmp when the Schedule::Cron jobs ran.

Thanks for the assistance in identifying the warning in the code.I have modified the warning, retaining the part to the process ID number and the last part with the code line number. This shorter message is a useful 'heartbeat' signal, in these early days of my Dada Mail implementation.

Thank you for your interest and help.

On 03-Nov-19 7:21 PM, Justin J justin@PROTECTED [Dada Mail Developers] wrote:
 
From: justin@PROTECTED

Hmm - do you get the same error, (Semaphore does not exist to delete), if you run the Schedule Jobs URL,just in your browser?Does that file,(/home/very/long/path/user/private/.dada_files/.tmp/scheduledtasks.lock)actually exist?

I guess if you want a bodge, you could just remove the line that throws that warning,

Look for:

warn "PID: $$ Semaphore does not exist to delete at, '" . $self->lockfile;

in,dada/DADA/App/ScheduledTasks.pm

and just remove it,

Cheers,

--

Justin J: Lead Dadaist.url: http://dadamailproject.com email: justin@PROTECTED twitter: @dadamail skype: leaddadaist

Dada Mail Announcements:http://dadamailproject.com/cgi-bin/dada/mail.cgi/list/dada_announce/

On Nov 2, 2019, at 6:33 PM, Chris Holt chris.holt@PROTECTED [Dada Mail Developers] dadadev@PROTECTED wrote:

From: chris.holt@PROTECTED Justin, thank you for your reply and thank you for developing Dada Mail and making it available.

The script for running Schedule::Cron is very simple and based on one of the examples supplied with Schedule::Cron.It's located in cgi-bin alongside dada and started with my SSH shell.So that it keeps going when I exit the shell, I use nohup with an ampersand to keep it in the background.So far, it's kept running. Dada Mail is run by Schedule::Cron using the precise curl command Dada Mail proposes via the admin pages.

I wasn't involved in the choice of webhost, which was made years ago. The package we have doesn't even have Cpanel, so it's been a challenge!

Thanks again

Chris

On 2 November 2019 22:11:00 GMT+00:00,"Justin J justin@PROTECTED[Dada Mail Developers]" dadadev@PROTECTED wrote:

From: justin@PROTECTED On Nov 2, 2019, at 3:48 PM, Chris Holt chris.holt@PROTECTED[Dada Mail Developers] dadadev@PROTECTED wrote:

Cron and crontab were also unavailable on the shared host, so I have made and uploaded Schedule::Cron, a cron-like Perl scheduler from metacpan, which seems to be working well. I find,however, that there are periodic messages in the errors file of this type:

Well, what's running the script you've whipped up using,Schedule::Cron? I'm wondering if the problem you're having is more a problem with Unix privileges than anything else. Is Dada Mail via the web server being run by a different user than your scheduler?This isn't so out of the ordinary, where the scheduler/cron is running as a different user than the webserver/Dada Mail, but this problem is usually gotten around by calling Dada Mail via curl - are you doing that, or are you calling it directly?

Also really interesting to me that this shared host account has such limited resources when it comes to niceties,but can be set up to use its own scheduler :)

--

Justin J: Lead Dadaist.url: http://dadamailproject.com email: justin@PROTECTED twitter: @dadamail skype: leaddadaist

Dada Mail Announcements:http://dadamailproject.com/cgi-bin/dada/mail.cgi/list/dada_announce/

On Nov 2, 2019, at 3:48 PM, Chris Holt chris.holt@PROTECTED[Dada Mail Developers] dadadev@PROTECTED wrote:

From: chris.holt@PROTECTED Hello Developers, I have just joined the list. Over the past couple of weeks, I have installed Dada Mail on the shared host of the website of the astronomy society I am involved in, to provide a discussion list.This was not without challenges(ssh cli install only, no CPAN,additional Perl modules for SSL built locally and uploaded, etc) but it is almost ready now for society members' use.

Cron and crontab were also unavailable on the shared host, so I have made and uploaded Schedule::Cron, a cron-like Perl scheduler from metacpan, which seems to be working well. I find,however, that there are periodic messages in the errors file of this type:

[Sat Nov 2 15:45:03 2019] mail.cgi: PID:48437 Semaphore does not exist to delete at,'/home/very/long/path/user/private/.dada_files/.tmp/scheduledtasks.lock at DADA/App/ScheduledTasks.pm line 210.With the scheduler applying the curl command to run Dada every five minutes, 24 of these are written every hour, so the errors file will balloon over time. Assuming this is normal behaviour, do most list admins accept it and find it somehow useful, or should I delve into the code and mute or shorten these messages?

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