Re: Filehandles
Stas Bekman [EMAIL PROTECTED] writes: [...] perl 5.8.0 internals are thread-safe, so does mod_perl 2.0-dev. By saying that perl is thread-safe, I mean that operations like push, =, /, map, chimp, etc. are thread-safe. ^ A thread-safe chimp; amazing! Try doing *that* in Java. -- Joe Schaefer
Re: Filehandles
On Fri, 30 Aug 2002, Stas Bekman wrote: I think he said mod_perl 2 in his inital post. Which I'm not sure really is all that swift with concurrant requests under threaded mpms (Win32 is limited to threaded mpms) ... least nobody seems 100% happy with the threaded mpm performance of mod_perl 2 yet (Stas? Anybody? How's it looking?) Caution: you are entering unchartered waters. first of all: you must use 5.8.0 with threaded mpms [ ... ] And, unfortunately for Win32, ActiveState has reportedly decided not to release a perl-5.8 binary build in the near future, but rather perhaps wait until a 5.8.1. -- best regards, randy
Re: Filehandles
Justin Luster wrote: Does anyone know anything about flock and mod_perl? Yes. There is no problem with flock and mod_perl. However, if you were to open a filehandle in startup.pl and then use that same filehandle after forking, that could be a problem. Personally I would suspect Windows in this case. I don't know about XP, but Windows 95/98/ME did not have a working flock. If XP is based on the NT code, it may not have that problem. Even so, I would try testing that first, or maybe asking about it on Win32 perl mailing list. - Perrin
Re: Filehandles
Thanks for responding so quickly. flock does work under Windows 2000 and above. The load tester that I'm using works fine with my script outside of mod_perl. My script works inside of mod_perl with only one concurrent user. When multiple concurrent users began hitting the script under mod_perl, using Apache::Registry or Apache::RunPerl all heck breaks loose. It seems that the file locking breaks down. Another thing that is totally bizarre is that stuff is being written to all kinds of files that I'm not writing to. Even my scripts themselves will sometimes have text appended to the end of them. Another problem is that Apache will give me an error message saying that it is trying to write to memory that is locked. Do you have any idea where I can go from here? What it the address of the Win32 mod_perl mailing list? Thanks. - Original Message - From: Perrin Harkins [EMAIL PROTECTED] To: Justin Luster [EMAIL PROTECTED] Cc: [EMAIL PROTECTED] Sent: Thursday, August 29, 2002 12:11 PM Subject: Re: Filehandles Justin Luster wrote: Does anyone know anything about flock and mod_perl? Yes. There is no problem with flock and mod_perl. However, if you were to open a filehandle in startup.pl and then use that same filehandle after forking, that could be a problem. Personally I would suspect Windows in this case. I don't know about XP, but Windows 95/98/ME did not have a working flock. If XP is based on the NT code, it may not have that problem. Even so, I would try testing that first, or maybe asking about it on Win32 perl mailing list. - Perrin
Re: Filehandles
Personally I would suspect Windows in this case. I don't know about XP, but Windows 95/98/ME did not have a working flock. If XP is based on the NT code, it may not have that problem. Even so, I would try testing that first, or maybe asking about it on Win32 perl mailing list. XP is based on the NT Kernel, and should have a working flock. I believe In recent versions of 5.6.1 flock() is emulated on the 9x kernel as well. However this doesn't mean mod_perl supports it, but I'm pretty sure (98%?) Activestate and Win32 perl does. I've never flock-ed in my life (never had a need) but I have been tracking Perl and Apache under Win32 for quite a while so take all this with a grain of salt. -Chris
Re: Filehandles
Thanks for responding so quickly. flock does work under Windows 2000 and above. The load tester that I'm using works fine with my script outside of mod_perl. My script works inside of mod_perl with only one concurrent user. When multiple concurrent users began hitting the script under mod_perl, using Apache::Registry or Apache::RunPerl all heck breaks loose. It seems that the file locking breaks down. Another thing that is totally bizarre is that stuff is being written to all kinds of files that I'm not writing to. Even my scripts themselves will sometimes have text appended to the end of them. Another problem is that Apache will give me an error message saying that it is trying to write to memory that is locked. Could this be a threading issue? Are you using 5.6.1 or 5.8 with mod_perl 2? I know that mod_perl 2 is far from ready for primetime especially under the threaded mpm's (which is what Win32 is forced to use). I use XP to develop for a Linux mod_perl 1 architecture so I'm raipdly getting out of my depth, but this sounds like the place to look. I've never heard of a Win32 specific mod_perl list ... :( -Chris
Re: Filehandles
Chris wrote: XP is based on the NT Kernel, and should have a working flock. I believe In recent versions of 5.6.1 flock() is emulated on the 9x kernel as well. However this doesn't mean mod_perl supports it It does actually, since mod_perl is Perl. Thanks for the flock clarification. - Perrin
Re: Filehandles
Justin Luster wrote: The load tester that I'm using works fine with my script outside of mod_perl. Does it work when running them concurrently under CGI? When multiple concurrent users began hitting the script under mod_perl, using Apache::Registry or Apache::RunPerl all heck breaks loose. Hmmm, which version of mod_perl are you using? If you're using 2.x, I can't help you there since I've never tried it on Win32. Maybe Randy will have some ideas. If you have 1.x, there is no concurreny under mod_perl -- requests are serialized. - Perrin
Re: Filehandles
The stress tool that I'm using is from Microsoft and is a free download. It is called Web Application Stress. There is a setting in this tool called Concurrent Connections (threads). As I mentioned before I am able to do this no problem under regular CGI with 10 concurrent users but when I run mod_perl all heck breaks loose. - Original Message - From: Perrin Harkins [EMAIL PROTECTED] To: Justin Luster [EMAIL PROTECTED] Cc: [EMAIL PROTECTED] Sent: Thursday, August 29, 2002 1:44 PM Subject: Re: Filehandles Justin Luster wrote: The load tester that I'm using works fine with my script outside of mod_perl. Does it work when running them concurrently under CGI? When multiple concurrent users began hitting the script under mod_perl, using Apache::Registry or Apache::RunPerl all heck breaks loose. Hmmm, which version of mod_perl are you using? If you're using 2.x, I can't help you there since I've never tried it on Win32. Maybe Randy will have some ideas. If you have 1.x, there is no concurreny under mod_perl -- requests are serialized. - Perrin
Re: Filehandles
Didn't mean to take this off list if I had. Heh. I'm using Perl 5.6 Unless someone with better knowledge pipes up, to the best of my knoweledge there are threading/concurrancy issues with mod_perl 2 and 5.6.1 ... I know that Randy has said in places that eventually the officiall recomdendation for Win32 Apache/mod_perl 2 will be 5.8 because it's theoretically more thread safe. I've never used either 5.8 (Activestate hasn't moved to it yet) nor mod_perl 2 (isn't finished yet, and I have a hard enough time supporting mod_perl 1) so all of this is based off hersay and rumor. -Chris - Original Message - From: Chris [EMAIL PROTECTED] To: [EMAIL PROTECTED] Cc: [EMAIL PROTECTED]; [EMAIL PROTECTED] Sent: Thursday, August 29, 2002 1:21 PM Subject: Re: Filehandles Thanks for responding so quickly. flock does work under Windows 2000 and above. The load tester that I'm using works fine with my script outside of mod_perl. My script works inside of mod_perl with only one concurrent user. When multiple concurrent users began hitting the script under mod_perl, using Apache::Registry or Apache::RunPerl all heck breaks loose. It seems that the file locking breaks down. Another thing that is totally bizarre is that stuff is being written to all kinds of files that I'm not writing to. Even my scripts themselves will sometimes have text appended to the end of them. Another problem is that Apache will give me an error message saying that it is trying to write to memory that is locked. Could this be a threading issue? Are you using 5.6.1 or 5.8 with mod_perl 2? I know that mod_perl 2 is far from ready for primetime especially under the threaded mpm's (which is what Win32 is forced to use). I use XP to develop for a Linux mod_perl 1 architecture so I'm raipdly getting out of my depth, but this sounds like the place to look. I've never heard of a Win32 specific mod_perl list ... :( -Chris -Chris
Re: Filehandles
Justin Luster wrote: The stress tool that I'm using is from Microsoft and is a free download. That isn't quite what I asked. Which version of mod_perl are you using? There is a setting in this tool called Concurrent Connections (threads). Regardless, mod_perl 1.x does not support multiple concurrent users on Windows. It will serialize those requests. - Perrin
Re: Filehandles
Justin Luster wrote: The stress tool that I'm using is from Microsoft and is a free download. That isn't quite what I asked. Which version of mod_perl are you using? There is a setting in this tool called Concurrent Connections (threads). Regardless, mod_perl 1.x does not support multiple concurrent users on Windows. It will serialize those requests. - Perrin I think he said mod_perl 2 in his inital post. Which I'm not sure really is all that swift with concurrant requests under threaded mpms (Win32 is limited to threaded mpms) ... least nobody seems 100% happy with the threaded mpm performance of mod_perl 2 yet (Stas? Anybody? How's it looking?) -Chris
Re: Filehandles
Chris wrote: I think he said mod_perl 2 in his inital post. Oops, you're right, I totally missed that. Sorry Justin. - Perrin
Re: Filehandles
On Thu, 29 Aug 2002, Justin Luster wrote: The stress tool that I'm using is from Microsoft and is a free download. It is called Web Application Stress. There is a setting in this tool called Concurrent Connections (threads). As I mentioned before I am able to do this no problem under regular CGI with 10 concurrent users but when I run mod_perl all heck breaks loose. I've tried a simple registry script that uses flock() (on WinXP), as well as one that just prints out the environment variables, using apache-2.0.40 and a recent cvs mod_perl-2 build. Using ApacheBench as ab -n ddd http://localhost/perl/script_name (where 'ddd' is the number of requests to do), on my system, when ddd exceeds about 1500 with perl-5.6.1, the tests hang, but things are OK in this realm with perl-5.8. So this problem may not have so much to do with flock(), but perhaps more to do with threading under perl-5.6.1 on Win32. If you're interested in comparing for your particular script, there's a perl-5.8/Apache/mod_perl binary, perl-5.8-win32-bin.tar.gz, at ftp://theoryx5.uwinnipeg.ca/pub/other/ - installation instructions are in the associated .readme file. -- best regards, randy kobes
Re: Filehandles
I think he said mod_perl 2 in his inital post. Which I'm not sure really is all that swift with concurrant requests under threaded mpms (Win32 is limited to threaded mpms) ... least nobody seems 100% happy with the threaded mpm performance of mod_perl 2 yet (Stas? Anybody? How's it looking?) Caution: you are entering unchartered waters. first of all: you must use 5.8.0 with threaded mpms perl 5.8.0 internals are thread-safe, so does mod_perl 2.0-dev. By saying that perl is thread-safe, I mean that operations like push, =, /, map, chimp, etc. are thread-safe. Operations that involve system calls, may or may not be thread-safe. This varies from OS to OS, and even varies for various versions of the same OS. e.g. localtime() is not thread-safe on platforms where asctime(3) is not thread-safe. other problematic ones are readdir(), srand(), ... there is another important issue. what some people are referring to as: thread-locality. Certain functions executed in a single thread affect the whole process e.g. if you chdir() in one thread, all other thread now see the cwd of that thread that chdir'ed. Other problematic functions are umask(), chroot(), %ENV... Getting back to the Justin's question, it's quite possible that thread-safety problems kick in. It could be that flock is not thread-safe. But I think the real problem is with chdir(), because Apache::Registry chdir()s to the dir of the script. Stop using Apache::Registry and start using ModPerl::Registry, which doesn't chdir(). Of course you cannot do any operations with relative path anymore. Arthur Bergman is working on some solutions for chdir(), but nothing was released so far. So you will have to wait or help Arthur to finish his work. So first try using ModPerl:Registry, which I expect will resolve the issue. If that doesn't help, please supply a *short* script that reproduces the problem. Which of course may not exhibit the same behavior on a different platform, but at least we can do some sanity check. __ Stas BekmanJAm_pH -- Just Another mod_perl Hacker http://stason.org/ mod_perl Guide --- http://perl.apache.org mailto:[EMAIL PROTECTED] http://use.perl.org http://apacheweek.com http://modperlbook.org http://apache.org http://ticketmaster.com
Re: Filehandles
I'm using Perl 5.6 Unless someone with better knowledge pipes up, to the best of my knoweledge there are threading/concurrancy issues with mod_perl 2 and 5.6.1 ... I know that Randy has said in places that eventually the officiall recomdendation for Win32 Apache/mod_perl 2 will be 5.8 because it's theoretically more thread safe. It's not threoretical, it's practical. There are thread-safety problems with perl interpreters in 5.6. It's possible that your code doesn't hit them, so 5.6 may work for you, but why taking the risk, use 5.8.0. expect mod_perl 2.0 *requiring* 5.8.0 for threaded mpms when it gets released. __ Stas BekmanJAm_pH -- Just Another mod_perl Hacker http://stason.org/ mod_perl Guide --- http://perl.apache.org mailto:[EMAIL PROTECTED] http://use.perl.org http://apacheweek.com http://modperlbook.org http://apache.org http://ticketmaster.com
