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William Chapman
jeddahbill at gmail.com
Wed Jun 4 13:45:58 EDT 2008
A follow-up on my "Windows performance problem": The problem was caused by the unexpected performance difference between the Linux and Windows versions of a JSON package - simplejson. **** It had nothing at all to do with mod_python. **** It turns out that simplejson's "speedup" feature was not functioning properly with Windows. To acheive better performance I needed to convert several performance-critial sections of my mod_python handler to use cjson instead. I would like to put in a good word, however, for both the cjson and simplejson packages. They are both excellent. simplejson has more features, is well documented, and very flexible; cjson is simpler, somewhat less flexible, and much faster. Thanks again to Graham and Dominique for keeping me properly focused (away from mod_python). Who knows for how long I would have wandered in the wilderness?! On Mon, Jun 2, 2008 at 11:21 AM, William Chapman <jeddahbill at gmail.com> wrote: > Graham & Dominique, > > Thanks for your responses and fresh insights! > > Progress so far: > Per your suggestion, I have tested the Windows XP (x64) & Linux > installations for static file serving performance, and found both to be > equally excellent. Actually, I think the Windows is even a bit livelier > than the Linux. > > Next step I'm considering: > (1) Reinstall Apache, Python, and mod_python, with versions to match those > installed on the Windows side of my alternate host. Because I generally > always choose the latest versions of everything I install, the older host > machine is probably a version or so behind. I might learn something there. > > Other information about my environment: > My web application uses sqlite (pysqlite binding) - and a few other Python > packages - but sqlite is the only one involved that's a performance driver. > Dominique mentioned the possible impact of other web application software > dependencies. Because I use sqlite, I'll also include it in the list of > software to reinstall, possibly reverting to an older version. > > By the way, I checked the Apache error logs on the (older) test-host and > the mod_python error messages are NOT present. I believe it's running > Apache 2.5.1 versus 2.5.2 on the new (problem) development-host. > > Thanks again for your help. I will post progress to the list. > Hasta la vista, ciao, > -- Bill Chapman > > > On Sun, Jun 1, 2008 at 6:49 PM, Graham Dumpleton < > graham.dumpleton at gmail.com> wrote: > >> 2008/6/1 William Chapman <jeddahbill at gmail.com>: >> > I'm new to this list, but have been using mod_python successfully for >> three >> > years in a web app served by both Linux (Ubuntu) and Windows (XP sp2 >> 32bit >> > AND 64bit). I use two hosts to serve: one for testing (semi-public); >> one >> > for development. Both hosts are dual-boot (Linux/Windows) and will >> serve >> > the identical web app installation from the same (NTFS file system) >> > directories. >> > >> > My problems started when the development host went belly-up and I >> rebuilt >> > the computer. The Windows installation was upgraded (?) from 32bit to >> 64bit >> > XP sp2. (I don't know if going to x64 Windows is part of the problem; I >> > doubt it.) Upon bringing up the new development host, all went well >> with >> > the Linux side, but under Windows, the web app is perfroming poorly. >> The >> > application accesses take much too long. Historically, the Windows & >> Linux >> > installations were comparable, and I never had performance complaints. >> Now, >> > the new Windows installation is 5x to 10x slower than previously. To >> > emphasize, the mod_python is "working," but very slowly, and comletely >> > unlike my previous experience with Windows/Apache/mod_python, not to >> mention >> > my current testing host which is fine. >> >> Have you tested speed of serving static files? That is, is it a >> mod_python specific problem or a problem with Apache as a whole? >> >> > The setup (all installed from binaries): >> > Windows XP x64 sp2 >> > apache 2.2.8 >> > mod_python 3.3.1 >> > Python 2.5.2 (installed separately) >> > >> > Note: I am not exactly sure of the order in which I installed >> > Apache/mod_python & Python 2.5. Could this matter? >> > I did uninstall and reinstall mod_python but performance/symptoms didn't >> > seem to change. >> > >> > The only clues: >> > Three lines together from apache error.log (long lines - STRETCH >> BROWSER) >> > (file also attached) (also see Graham's email here.): >> > [Fri May 30 17:38:57 2008] [error] python_init: Python version mismatch, >> > expected '2.5', found '2.5.2'. >> > [Fri May 30 17:38:58 2008] [error] python_init: Python executable found >> > 'C:\\Program Files (x86)\\Apache Software >> > Foundation\\Apache2.2\\bin\\httpd.exe'. >> > [Fri May 30 17:38:58 2008] [error] python_init: Python path being used >> > >> 'C:\\WINDOWS\\system32\\python25.zip;C:\\Python25\\Lib;C:\\Python25\\DLLs;C:\\Python25\\Lib\\lib-tk;;C:\\Program >> > Files (x86)\\Apache Software Foundation\\Apache2.2\\bin'. >> > >> > I have read several of the threads from the list on this subject and am >> > confused about the following points: >> > (1) In the "Python version mismatch" error, the "found" version matches >> the >> > version of Python I installed on the Windows machine. mod_python >> "expected >> > 2.5". Where is that supposed to come from? I could not find Python 2.5 >> at >> > http://python.org. >> >> You obviously used a prebuilt version of mod_python for Windows. That >> prebuilt version used Python 2.5 when compiled. That is what it means. >> >> > (2) Apparently the "Python version mismatch" error message is not enough >> to >> > stop mod_python from working, because it is "working." >> >> On Windows, because Python is obtained via a DLL, the warning can be >> ignored as APIs will be compatible. In other words, doesn't matter >> that mod_python was originally compiled for older patch revision. >> >> > (3) The "Python executable found" error message points to >> > "...\\Apache2.2\\bin\\httpd.exe" This does not look like a "Python >> > executable." (?) >> >> Outputing this was thought to be a good idea, but not actually of much >> use. What it is simply showing is that Python is running embedded >> inside of Apache httpd executable. In other words, not standalone >> python.exe. >> >> > (4) The "Python path being used" error message specifies a series of >> paths. >> > Where do those paths come from? Can I affect those values? >> >> To a degree. See PythonPath directive, although changes may with this >> may not show up in startup messages as they are applied later. You can >> also change it by fiddling Windows registry, but you shouldn't do that >> if you can help it. >> >> > Taken as a >> > whole it doesn't match the system path environment variable I'm able to >> set >> > as a Windows user. >> >> This is not the PATH variable, it is related to Python module search path. >> >> > Random thought: I always thought that mod_python included an embedded >> Python >> > interpreter, but reading suggests mod_python links to Python libraries. >> >> Both observations are true. Python is used in embedded mode, but code >> comes from DLL. >> >> > My analysis: I suspect that the principle benefit of a mod_python >> > installation is not being realized. It seems that the interpreter is >> having >> > to be restarted for each access. Is there another explanation for the >> poor >> > performance? >> >> Your understanding is wrong. A new interpreter is not created on each >> request. >> >> There is obviously still something wrong with your configuration or >> perhaps with the web application which only manifests with this >> configuration. >> >> Start out by seeing if Apache as a whole is working okay by testing >> static file serving. >> >> Graham >> >> >> > At any rate I would greatly appreciate any suggestions or insights you >> might >> > have!! >> > >> > With many thanks, >> > -- Bill Chapman >> > >> > >> > _______________________________________________ >> > Mod_python mailing list >> > Mod_python at modpython.org >> > http://mailman.modpython.org/mailman/listinfo/mod_python >> > >> > >> > > -------------- next part -------------- An HTML attachment was scrubbed... URL: http://mm_cfg_has_not_been_edited_to_set_host_domains/pipermail/mod_python/attachments/20080604/012653db/attachment.html
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