[Zope-DB] ZOracleDA/SP.py: non volatile error variable

[Willi Langenberger]

Hi Chris and all!


We found out, that every call to a Z Oracle Procedure is a write
operation wrt the object store (seems harmless, but killed us big
time[1]).

With the following patch (change self._errors to the volatile
self._v_errors), a procedure call triggers no ZODB write any more (and
our application worked fine):


zope at bach-s3:~/DCOracle2-20031104$ diff -u SP.py.ori SP.py
--- SP.py.ori   2002-12-21 21:29:06.000000000 +0100
+++ SP.py       2003-11-04 14:08:55.000000000 +0100
@@ -192,14 +192,14 @@
     def _connect(self):
         db = self._v_db = getattr(self,self.connection)() # Get connection
         c = db.cursor                          # Get cursor
-        self._errors = 0
+        self._v_errors = 0
         if self.procname:
             try:
                 p = c.findproc(self.procname)        # Get procedure
                 self._v_proc = p
             except DCOracle2.DatabaseError:
-                self._errors = self._errors + 1
-                if self._errors > 3: raise
+                self._v_errors = self._v_errors + 1
+                if self._v_errors > 3: raise
                 
 
     def _finish(self, *ignored):


Thanks,


\wlang{}


[1]: We have a zeo cluster with 5 Zope Instances to handle
registration at our university. Each request (and there are many)
calls an Oracle procedure. These ZODB write operations brought the
system down :-(

-- 
Willi.Langenberger at wu-wien.ac.at                Fax: +43/1/31336/9207
Zentrum fuer Informatikdienste, Wirtschaftsuniversitaet Wien, Austria