Wow, thanks Eric ! That seems to be very nice, I'll give it a try and will report later here if avoiding system() calls reduce the number of aborted connections.
Heiko Am 18.02.2010 um 17:24 schrieb eric.b...@barclayscapital.com: > I'm starting to use Gearman to get around this whole problem. We use a lot > of external processes for many things, so this issue wtih Apache2 really bit > me hard in the bee-hind. I've gone to great lengths to work around it, but > so far the job queue approach seems to be the most elegant and least > problematic approach. Of course, the recommendation came from the gentle > folks on this list originally. > > Eric > > From: Heiko Weber [mailto:he...@wecos.de] > Sent: Thursday, February 18, 2010 3:22 AM > To: Salvador Ortiz Garcia > Cc: mod_perl list > Subject: Re: [mp2] mod_perl closes apache's stdin and/or stdout > > Salvador, > > to avoid such issues my "external" tasks don't use STDOUT, STDIN or STDERR. > They take their parameters from control files and write their results back to > a status file. This tasks don't send any output back to the browsers. As I > said, usually some "sudo's to change some system settings. > > Well, I could replace all system() calls and just store the task jobs into a > database table, to schedule a background job with cron to check and complete > this tasks, but then I lost the immediately feedback to the user/browser ... > AND this is a lot of work for me - unless I can exactly repeat the issue I > am not sure if it is worth to try it. > > Currently it feels to me like a "leakage", sometimes a httpd/mod_perl/process > do something, and later (maybe when working on the next client request) > STDOUT is closed. This makes it hard to create a sample program to repeat it. > Within a single script I can do almost everything: call system(), open DBI > connections, write to STDOUT, ... everything seems to be fine. > > Heiko > > Am 16.02.2010 um 23:26 schrieb Salvador Ortiz Garcia: > >> On 02/05/2010 12:16 PM, Heiko Weber wrote: >>> Hi André, >>> >>> I know what you mean, and I can't agree with you - the server response time >>> is really low - most pages are finished loading in less 1-2 seconds, and >>> the overall load of the server is at a low level. I believe there is an >>> issue, maybe something what Jon is talking about, I also using some >>> "system()" call's to execute sendmail or sudo tasks, so maybe STDOUT really >>> gets closed - I have no idea. I only see the abort messages in errorlog >>> very frequent, maybe 3-4 per minute. >>> >>> Heiko >>> >> Of course STDOUT, STDIN, and STDERR get closed, not by mod_perl but by >> apache. Every UNIX process when demonized must close them to detach from >> its controling terminal. >> >> Apache reopens STDERR to its log file, but STDOUT and STDIN remain closed. >> >> Maybe de confusion arises from the fact that when executing a CGI the server >> connects them to the client socket, but in mod_perl you are in the deamon >> process space. >> >> Please check "Advanced Programing in the UNIX environment", chapter 13: >> "Daemon processes" by W. Richard Stevens. >> >> Regards. >> >> Salvador. > > -- > Wecos <> Heiko Weber Computer Systeme > D-21644 Sauensiek <> Immenweg 5 > he...@wecos.de <> http://www.wecos.de > _______________________________________________ > > This e-mail may contain information that is confidential, privileged or > otherwise protected from disclosure. If you are not an intended recipient of > this e-mail, do not duplicate or redistribute it by any means. Please delete > it and any attachments and notify the sender that you have received it in > error. Unless specifically indicated, this e-mail is not an offer to buy or > sell or a solicitation to buy or sell any securities, investment products or > other financial product or service, an official confirmation of any > transaction, or an official statement of Barclays. Any views or opinions > presented are solely those of the author and do not necessarily represent > those of Barclays. This e-mail is subject to terms available at the following > link: www.barcap.com/emaildisclaimer. By messaging with Barclays you consent > to the foregoing. Barclays Capital is the investment banking division of > Barclays Bank PLC, a company registered in England (number 1026167) with its > registered office at 1 Churchill Place, London, E14 5HP. This email may > relate to or be sent from other members of the Barclays Group. > _______________________________________________ -- Wecos <> Heiko Weber Computer Systeme D-21644 Sauensiek <> Immenweg 5 he...@wecos.de <> http://www.wecos.de Tel. +49 (4169) 91000 <> Fax +49 (4169) 919033 _______________________________________________________________ This email may contain confidential and privileged material for the sole use of the intended recipient. Any review or distribution by others is strictly prohibited. If you are not the intended recipient please contact the sender and delete all copies. _______________________________________________________________ Diese E-Mail kann digital signiert sein. Falls Ihr E-Mail-Programm nicht ueber die notwendigen Prueffunktionen verfuegt, ignorieren Sie bitte die angehaengte Signatur-Datei. _______________________________________________________________ This email may be digitally signed. If your email software does not support the necessary validation feature, please disregard the attached signature file. _______________________________________________________________
