[Zope] ZMySQLDA-2.0.9b1 released

Harald Koschinski harald.koschinski@friatec.de
Mon, 04 Feb 2002 15:20:51 +0100


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I am now live since 8 hours with zmysqlda 2.0.9, mysql-python 0.9.1 and 
what happend:
The wonder is there - no more crashes. :-)

So I believe, Andy's analysis is right - thank you very much.

O Happy Day :-))

Harald

Andy Dustman wrote:

>On Fri, 2002-02-01 at 09:12, Matthew T. Kromer wrote:
>
>>Harald Koschinski wrote:
>>
>>>MySQLdb-0.9.2a2 is not compiling :-((
>>>
>>>intranet:/usr/local/opt/Zope/products/MySQL-python-0.9.2a2 # python 
>>>setup.py build
>>>[...]
>>>/usr/i486-suse-linux/bin/ld: cannot find -lmysqlclient_r
>>>collect2: ld returned 1 exit status
>>>error: command 'gcc' failed with exit status 1
>>>
>>>No Problems with 0.9.1 on the same mashine
>>>
>>But the 0.9.1 you built is a time bomb waiting to blow up on you.  If 
>>you don't link with the reentrant mysqlclient libraries your python 
>>adapater isn't thread safe.
>>
>>I expect you can edit the Setup.py file and change the "use threaded 
>>client libraries" switch to use the non-threaded library.  If you do 
>>that and use it in Zope though, you are asking for crashes.
>>
>
>The funny thing is, the "non-thread-safe" libraries are not all that
>unsafe. I've done a lot of testing (outside of Zope) of the
>non-thread-safe libraries in a threaded environment, and they seem to
>work fine. The docs currently say [my comments in brackets]:
>
....

>
>
>So as near as I can tell, even using the non-thread-safe library with
>Zope *ought* to be safe, so long as multiple threads are not using a
>connection at the same time. The most likely explanation for the crashes
>people occasionally see is that there is nothing preventing Zope from
>simultanous multiple access of the database connection object. If that's
>true, ZMySQLDA 2.0.9 ought to fix it. But then I would expect crashes
>more often than what actually seems to happen.
>

regards

Harald Koschinski
_____________________________________________________________________

FRIATEC Aktiengesellschaft
Informationssysteme und Organisation            
Tel. 0621 - 486 - 1454
Fax. 0621 - 486 - 1840
Steinzeugstrasse 50
mailto:harald.koschinski@friatec.de
D-68229 Mannheim



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I am now live since 8 hours with zmysqlda 2.0.9, mysql-python 0.9.1 and what
happend:<br>
The wonder is there - no more crashes. :-)<br>
<br>
So I believe, Andy's analysis is right - thank you very much.<br>
<br>
O Happy Day :-))<br>
<br>
Harald<br>
<br>
Andy Dustman wrote:<br>
<blockquote type="cite" cite="mid:1012575691.25374.44.camel@chef.neosouth.net">
  <pre wrap="">On Fri, 2002-02-01 at 09:12, Matthew T. Kromer wrote:<br></pre>
  <blockquote type="cite">
    <pre wrap="">Harald Koschinski wrote:<br><br></pre>
    <blockquote type="cite">
      <pre wrap="">MySQLdb-0.9.2a2 is not compiling :-((<br><br>intranet:/usr/local/opt/Zope/products/MySQL-python-0.9.2a2 # python <br>setup.py build<br>[...]<br>/usr/i486-suse-linux/bin/ld: cannot find -lmysqlclient_r<br>collect2: ld returned 1 exit status<br>error: command 'gcc' failed with exit status 1<br><br>No Problems with 0.9.1 on the same mashine<br><br></pre>
      </blockquote>
      <pre wrap="">But the 0.9.1 you built is a time bomb waiting to blow up on you.  If <br>you don't link with the reentrant mysqlclient libraries your python <br>adapater isn't thread safe.<br><br>I expect you can edit the Setup.py file and change the "use threaded <br>client libraries" switch to use the non-threaded library.  If you do <br>that and use it in Zope though, you are asking for crashes.<br></pre>
      </blockquote>
      <pre wrap=""><!----><br>The funny thing is, the "non-thread-safe" libraries are not all that<br>unsafe. I've done a lot of testing (outside of Zope) of the<br>non-thread-safe libraries in a threaded environment, and they seem to<br>work fine. The docs currently say [my comments in brackets]:<br></pre>
      </blockquote>
....<br>
      <blockquote type="cite" cite="mid:1012575691.25374.44.camel@chef.neosouth.net">
        <pre wrap=""><br><br>So as near as I can tell, even using the non-thread-safe library with<br>Zope *ought* to be safe, so long as multiple threads are not using a<br>connection at the same time. The most likely explanation for the crashes<br>people occasionally see is that there is nothing preventing Zope from<br>simultanous multiple access of the database connection object. If that's<br>true, ZMySQLDA 2.0.9 ought to fix it. But then I would expect crashes<br>more often than what actually seems to happen.<br><br></pre>
        </blockquote>
        <br>
        <pre class="moz-signature" cols="$mailwrapcol">regards<br><br>Harald Koschinski<br>_____________________________________________________________________<br><br>FRIATEC Aktiengesellschaft<br>Informationssysteme und Organisation            <br>Tel. 0621 - 486 - 1454<br>Fax. 0621 - 486 - 1840<br>Steinzeugstrasse 50<br><a class="moz-txt-link-freetext" href="mailto:harald.koschinski@friatec.de">mailto:harald.koschinski@friatec.de</a><br>D-68229 Mannheim<br><br></pre>
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