[ZODB-Dev] MemoryLeaks using multiple DBs ?

[Heiko Hees]

Hi,

i am developing a webservice and want to use ZODB with Webware. I 
planned to use a seperate FileStorage for each user. Unfortunally it 
seems like ZODB doesn't free Storage when connections are closed.

The following script opens and closes 10 seperate connections and writes 
  10MB of data into each. Memoryusage  goes up to 107MB on my system :-(
I am using Python 2.2.1 and StandaloneZODB 1.0 on Linux.


Any thoughts/alternatives or suggestions?

Regards

Heiko Hees




#!/usr/bin/python
import ZODB, sys, time, types
from ZODB import FileStorage, DB
from BTrees.IOBTree import IOBTree


def get_refcounts():
     d = {}
     sys.modules
     # collect all classes
     for m in sys.modules.values():
         for sym in dir(m):
             o = getattr (m, sym)
             if type(o) is types.ClassType:
                 d[o] = sys.getrefcount (o)
     # sort by refcount
     pairs = map (lambda x: (x[1],x[0]), d.items())
     pairs.sort()
     pairs.reverse()
     return pairs

def print_top(num):
     for n, c in get_refcounts()[:1000]:
         print '%10d %s' % (n, c.__name__)

if __name__ == '__main__':
     import os
     try:
         path = sys.argv[1]
         assert(os.path.isdir(path))
     except:
         print "usage:%s dir" % sys.argv[0]
         sys.exit(10)

     for i in range(10): # open, write, close 10 seperate storages
         # open fs,db,connection -> write data -> close
         fs = FileStorage.FileStorage("%s/%d" % (path,i))
         db = DB(fs)
         connection = db.open()
         root = connection.root()
         root['data'] = IOBTree()
         for i in range(1024 * 10): # create 10MB data in storage
             root['data'][i] = "x"*1024
         get_transaction().commit()
         #root['data']._p_jar.cacheGC()
         connection.close()
         db.close()
         fs.close()

     # check whats left

     print_top(1000)
     # reports:
     # 27 Connection
     # ...
     # 11 FileStorage
     # ...
     # 7 DB

     print "check size w/o user:"
     # top says:
     # PID USER     PRI  NI  SIZE  RSS SHARE STAT %CPU %MEM   TIME COMMAND
     # 734 heiko      9   0  107M 107M  1364 S     0.0 43.2   0:18 
zodbMemTest.py


     time.sleep(1000)








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