On Dec 14, 11:20 pm, osimons <[email protected]> wrote:
> On Dec 14, 12:46 pm, Omry Yadan <[email protected]> wrote:
>
> > from sqlite3-3.5.9/src/main.c line 31:
>
> > int sqlite3_threadsafe(void){ return SQLITE_THREADSAFE; }
>
> > osimons wrote:
> > > The sqlite.threadsafety read setting seems to be set to 1 in source,
> > > reagardless of compile settings
>
> Right, I'm sure it is in there somewhere - it is just not exposed in
> any Python information structure that I can find. Having to read C
> libs directly will complicate our own setup.
>
> That is still also just one part of the puzzle, as the frontend also
> matters. It works really well for you as things are compiled the right
> way, and you use WSGI daemon mode with one process serving through
> threads - essentially same strategy as all Windows frontends (Apache
> mpm_nt never creates more than one process to serve requests).
> However, if you use any frontend that forks to serve connections, the
> pool is a very bad idea - essentially making new copies of the pool
> (and connections) in new processes that have no means of coordinating
> their actions.
Note that in Apache, whether one uses mod_python or mod_wsgi, stuff
like Trac initialisation and therefore database connection creation,
happens after forking of the long running process. Thus, there is no
chance that an existing setting of connections would be inherited/
copied across a forking of the process created to handle requests.
Graham
> And, as the db code is essential to any Trac loading,
> it will likely be populated with connections before requests start
> coming in. Forking and db pooling will be unpredictable.
>
> So, the check as it stands is the lowest common denominator of
> "trusted" pooling. Question is, how can we improve the checks to also
> include other safe situations? One idea that springs to mind is to
> start off non-pooled, but as requests come in we can read req.environ
> wsgi settings that on my (OSX/Apache 2.2.10) mod_wsgi daemon setup
> shows as:
>
> wsgi.multiprocess: False
> wsgi.multithread: True
> wsgi.run_once: False
>
> However, on my mod_python test setup it reads:
>
> wsgi.multiprocess: True
> wsgi.multithread: False
> wsgi.run_once: False
>
> For the total set of versions/platforms/settings deemed as safe, we
> could then check and turn on pooling for the process when first
> request is made.
>
> :::simon
>
> https://www.coderesort.com
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