I only looked at Apache::DBI not DBI document. My test program works. It reconnects to database OK. I ran it multiple times and every time it reconnects OK. But Apache::DBI doesn't work. You saw the previous debugging info. Where is the problem?
- xinhuan From: Perrin Harkins <phark...@gmail.com<mailto:phark...@gmail.com>> Date: Thursday, November 7, 2013 1:00 PM To: Xinhuan Zheng <xzh...@christianbook.com<mailto:xzh...@christianbook.com>> Cc: Adam Prime <adam.pr...@utoronto.ca<mailto:adam.pr...@utoronto.ca>>, "modperl@perl.apache.org<mailto:modperl@perl.apache.org>" <modperl@perl.apache.org<mailto:modperl@perl.apache.org>> Subject: Re: Apache::DBI connect It is in the DBI documentation. Search for "0E0". - Perrin On Thu, Nov 7, 2013 at 12:41 PM, Xinhuan Zheng <xzh...@christianbook.com<mailto:xzh...@christianbook.com>> wrote: So it returns string '0E0'? The document didn't say that. - xinhuan On 11/7/13 11:44 AM, "Adam Prime" <adam.pr...@utoronto.ca<mailto:adam.pr...@utoronto.ca>> wrote: >perl -e "if ('0E0') { print qq[hi\n] }" >hi > >OE0 as a string evaluates to true. If you use it as a bareword / >numeric then it's false, which is what your eval example below is doing. > >Adam > > >On 13-11-07 11:29 AM, Xinhuan Zheng wrote: >> one correct - In both cases, the return value is evaluated to false. >> >> How do you distinguish? >> >> - xinhuan >> >> From: Xinhuan Zheng >> <xzh...@christianbook.com<mailto:xzh...@christianbook.com> >> <mailto:xzh...@christianbook.com<mailto:xzh...@christianbook.com>>> >> Date: Thursday, November 7, 2013 11:12 AM >> To: Perrin Harkins <phark...@gmail.com<mailto:phark...@gmail.com> >> <mailto:phark...@gmail.com<mailto:phark...@gmail.com>>> >> Cc: mod_perl list <modperl@perl.apache.org<mailto:modperl@perl.apache.org> >><mailto:modperl@perl.apache.org<mailto:modperl@perl.apache.org>>> >> Subject: Re: Apache::DBI connect >> >>> I don't actually understand why you did that. What was wrong with the >>>normal ping? >> >> With Oracle DRCP, even though ping succeeds, the connection to the >> server process is actually terminated. Or ora_ping() may return 0E0 >> "zero but true" and undef. I don't know. ora_ping() is foreign to me. I >> made the change based on what Apache::DBI the document said. >> >>> In any case, there's no need to change the Apache::DBI code, even with >>>your "select 1 from dual" test. It returns a true value (0E0) if it >>>succeeds and a false value (undef) if it fails. >> >> In both cases, the return value is evaluated to true: >> >> 200: if ($Connected{$Idx} and (!$needping or >>eval{$Connected{$Idx}->ping})) >> >> eval{0E0} and eval{undef} both return true. I did test that. How do you >> distinguish? >> >>> Did your script succeed in reconnecting after it lost the connection? >> >> Yes. >> >>> Yes, I haven't forgotten about that, but I haven't had time to work on >>>it yet. You can try fixing it yourself by looking at the code in >>>Apache::DBI that checks if the server is starting under apache 1.x. >>>Otherwise, I will eventually get to it. >> >> I don't understand that piece of code. I can't do the change. Hope you >> can help. >> >> - xinhuan >> >> From: Perrin Harkins <phark...@gmail.com<mailto:phark...@gmail.com> >> <mailto:phark...@gmail.com<mailto:phark...@gmail.com>>> >> Date: Thursday, November 7, 2013 11:00 AM >> To: Xinhuan Zheng <xzh...@christianbook.com<mailto:xzh...@christianbook.com> >> <mailto:xzh...@christianbook.com<mailto:xzh...@christianbook.com>>> >> Cc: mod_perl list <modperl@perl.apache.org<mailto:modperl@perl.apache.org> >><mailto:modperl@perl.apache.org<mailto:modperl@perl.apache.org>>> >> Subject: Re: Apache::DBI connect >> >> On Thu, Nov 7, 2013 at 9:46 AM, Xinhuan Zheng >> <xzh...@christianbook.com<mailto:xzh...@christianbook.com> >> <mailto:xzh...@christianbook.com<mailto:xzh...@christianbook.com>>> wrote: >>>The $ok is undef. In the case if the test does succeed (like the first >>>select), $ok returns 0E0. >> >> That all sounds good. 0E0 is a true value in Perl. It means "zero but >> true." And undef is a false value. You don't need to test for undef. >> >>> Since I changed DBD::Oracle subroutine ping to use 'select 1 from >>>dual', >> >> I don't actually understand why you did that. What was wrong with the >> normal ping? >> >> In any case, there's no need to change the Apache::DBI code, even with >> your "select 1 from dual" test. It returns a true value (0E0) if it >> succeeds and a false value (undef) if it fails. >> >> Did your script succeed in reconnecting after it lost the connection? >> >>> I have another request. The Apache::DBI cached a dead database handle >>>for apache version 1.3.42 if startup.pl<http://startup.pl> >>><http://startup.pl> create a >>>database handle. The apache >> child processes inherits this dead handle. It doesn't cause application >> error but it does take memory space. If there is many apache processes, >> that's not good. Can you please identify and change the code for this >> problem? >> >> Yes, I haven't forgotten about that, but I haven't had time to work on >> it yet. You can try fixing it yourself by looking at the code in >> Apache::DBI that checks if the server is starting under apache 1.x. >> Otherwise, I will eventually get to it. >> >> - Perrin >> >
