Issue in pooling multiple mysql connection

Question

I tried implementing the mysql pooling but there is an issue: I am parsing mysql connection credentials from an env variable which is basically a dictionary and has multiple databases credentials in it.

   dict={'db1': {'username':**** ,'password':**** ,'database':*****,'host':****,'uri': mysql url with username ,password,database}, 
         'db2': {'username': ****, 'hostname': *****,host: ******, 'password': ***,'uri': mysql url with username ,password,database}}

global conn
conn={}
def connect():
 cred=json.loads(os.environ['dict'])
 for db in cred:
   multiple_databases=cred[db]['uri']
   url=urlparse.urlparse(multile_databases)           
   conn[db]={'user':'url.username','password':'url.password','host':'url.hostname','database':'url.path[1:]'}
   cnx = mysql.connector.connect(pool_name = "mypool",
                          pool_size = 3,
                          **conn[db])
connect()

Issue here is only one connection is getting opened and it is for database 'db2'.

when i execute the same code without implementing pooling,both connections work fine/open.

  for db in cred:
   multiple_databases=cred[db]['uri']
   url=urlparse.urlparse(multile_databases)           
   conn[db]=mysql.connector.connect(user=url.username,password=url.password,host=url.hostname,database=url.path[1:])

Question:When implementing pooling why both connection is not getting opened?

Answer 1

Figured it out

def conn1():
 pool_size = 3
ser=json.loads(os.environ['dict'])
for db in ser:
  instance_1=ser[db]['uri']
  url=urlparse.urlparse(instance_1)
  pool[db]=PooledDB(mysql.connector, pool_size, user=url.username, password=url.password, host=url.hostname, database=url.path[1:])
  cnx=[None,]*pool_size
  for i in xrange(0,pool_size):
 cnx[i]=pool[db].connection()
 cursor=cnx[i].cursor()
 cursor.execute('SELECT CONNECTION_ID()')
 print "Cnx %d has ID %d" % (i+1,cursor.fetchone()[0])