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Re: [Bug 1013223] Re: concurrent users over xmlrpc

To: openerp-india@xxxxxxxxxxxxxxxxxxx
From: Marcos Mendez <marcos@xxxxxxxxxxxx>
Date: Mon, 18 Jun 2012 13:22:29 -0000
Reply-to: Bug 1013223 <1013223@xxxxxxxxxxxxxxxxxx>
Sender: bounces@xxxxxxxxxxxxx
*** This bug is a duplicate of bug 992525 ***
    https://bugs.launchpad.net/bugs/992525

Great. Any way to push this to higher priority than low? This is a
serious issue for us.

On Jun 18, 2012, at 9:03 AM, Amit Parik (OpenERP) wrote:

> *** This bug is a duplicate of bug 992525 ***
>    https://bugs.launchpad.net/bugs/992525
> 
> ** This bug is no longer a duplicate of bug 949907
>   could not obtain lock on row in relation "res_users"
> 
> ** This bug has been marked a duplicate of bug 992525
>   TransactionRollbackError due to concurrent update could be better handled
> 
> -- 
> You received this bug notification because you are subscribed to the bug
> report.
> https://bugs.launchpad.net/bugs/1013223
> 
> Title:
>  concurrent users over xmlrpc
> 
> Status in OpenERP Server:
>  New
> 
> Bug description:
>  Setup:
> 
>  1 x ubuntu 12.04 LTS server (all updates applied)
>  python 2.7.3
>  postgresql 9.1
>  openerp 6.1
> 
>  We wanted to run some load tests based on the simple create_partner.py
>  example that everyone uses. When we put 100 concurrent users, logging
>  in and creating 100 partners (one at a time) using JMeter we get some
>  errors:
> 
>  2012-06-12 19:51:42,843 2210 DEBUG ? openerp.sql_db: ConnectionPool(used=0/count=64/max=64) Put connection to 'host=localhost port=5432 user=openerp password=xxxxxxx dbname=openerp' in pool
>  2012-06-12 19:51:42,843 2210 ERROR ? openerp.osv.osv: Uncaught exception
>  Traceback (most recent call last):
>    File "/usr/lib/pymodules/python2.7/openerp/osv/osv.py", line 121, in wrapper
>      return f(self, dbname, *args, **kwargs)
>    File "/usr/lib/pymodules/python2.7/openerp/osv/osv.py", line 176, in execute
>      res = self.execute_cr(cr, uid, obj, method, *args, **kw)
>    File "/usr/lib/pymodules/python2.7/openerp/osv/osv.py", line 164, in execute_cr
>      return getattr(object, method)(cr, uid, *args, **kw)
>    File "/usr/lib/pymodules/python2.7/openerp/osv/orm.py", line 4154, in create
>      cr.execute('insert into "'+self._table+'" (id'+upd0+") values ("+str(id_new)+upd1+')', tuple(upd2))
>    File "/usr/lib/pymodules/python2.7/openerp/sql_db.py", line 152, in wrapper
>      return f(self, *args, **kwargs)
>    File "/usr/lib/pymodules/python2.7/openerp/sql_db.py", line 212, in execute
>      res = self._obj.execute(query, params)
>  TransactionRollbackError: could not serialize access due to concurrent update
>  CONTEXT:  SQL statement "SELECT 1 FROM ONLY "public"."res_users" x WHERE "id" OPERATOR(pg_catalog.=) $1 FOR SHARE OF x"
>  2012-06-12 19:51:42,844 2210 ERROR ? openerp.netsvc: could not serialize access due to concurrent update
> 
>  After seeing this error I decided to update the db_maxconn property to
>  1000, to ensure you have enough connections for the test. But I still
>  see errors like the one below:
> 
>  2012-06-12 19:57:14,811 6327 DEBUG ? openerp.sql_db: ConnectionPool(used=19/count=85/max=1000) Put connection to 'host=localhost port=5432 user=openerp password=xxxxxxx dbname=openerp' in pool
>  2012-06-12 19:57:14,811 6327 ERROR ? openerp.netsvc: Object Error
>  Object res.partner doesn't exist
> 
>  2012-06-12 20:20:26,636 15119 ERROR ? openerp.sql_db: bad query: SELECT id from res_users
>                            WHERE login='admin' AND password='admin'
>                                  AND active FOR UPDATE NOWAIT
>  Traceback (most recent call last):
>    File "/usr/lib/pymodules/python2.7/openerp/sql_db.py", line 212, in execute
>      res = self._obj.execute(query, params)
>  OperationalError: could not obtain lock on row in relation "res_users"
> 
>  2012-06-12 20:20:26,745 15119 ERROR ? openerp.sql_db: bad query: insert into "res_partner" (id,"customer","lang","name","color","employee","company_id","supplier","active",create_uid,create_date) values (43536,'True','en_US','Partner - 1 ',0,'False',1,'False','True',1,(now() at time zone 'UTC'))
>  Traceback (most recent call last):
>    File "/usr/lib/pymodules/python2.7/openerp/sql_db.py", line 212, in execute
>      res = self._obj.execute(query, params)
>  TransactionRollbackError: could not serialize access due to concurrent update
> 
>  2012-06-12 20:20:26,779 15119 ERROR ? openerp.sql_db: bad query: insert into "res_partner" (id,"customer","lang","name","color","employee","company_id","supplier","active",create_uid,create_date) values (43537,'True','en_US','Partner - 1 ',0,'False',1,'False','True',1,(now() at time zone 'UTC'))
>  Traceback (most recent call last):
>    File "/usr/lib/pymodules/python2.7/openerp/sql_db.py", line 212, in execute
>      res = self._obj.execute(query, params)
>  TransactionRollbackError: could not serialize access due to concurrent update
> 
>  Please find attached the JMeter file you can use to launch the test.
>  You will need to change the IP addresses, admin account/password and
>  database probably.
> 
>  The test environment consists of one box with Ubuntu 12 LTS Server with Postgres 9.1 and OpenERP 6.1 (CRM + Employee Directory modules + demo data). 
>  	/usr/bin/openerp-server --db_user=openerp --db_password=openerp --db_host=localhost --db_port=5432 --no-database-list --log-sq --db_maxconn=1000
> 
>  Same test with gunicorn sync (no gevent). Please find attached the
>  gunicorn configuration. Please look at this well. There could be
>  concurrency issues with some of the underlying SQL statements.
> 
>  2012-06-12 17:17:33,826 1368 ERROR openerp openerp.sql_db: bad query: insert into "res_partner" (id,"customer","lang","name","color","employee","company_id","supplier","active",create_uid,create_date) values (44646,'True','en_US','Partner - 1 ',0,'False',1,'False','True',1,(now() at time zone 'UTC'))
>  Traceback (most recent call last):
>    File "/usr/lib/pymodules/python2.7/openerp/sql_db.py", line 212, in execute
>      res = self._obj.execute(query, params)
>  TransactionRollbackError: could not serialize access due to concurrent update
>  CONTEXT:  SQL statement "SELECT 1 FROM ONLY "public"."res_users" x WHERE "id" OPERATOR(pg_catalog.=) $1 FOR SHARE OF x"
> 
>  2012-06-12 17:17:33,827 1368 ERROR openerp openerp.osv.osv: Uncaught exception
>  Traceback (most recent call last):
>    File "/usr/lib/pymodules/python2.7/openerp/osv/osv.py", line 121, in wrapper
>      return f(self, dbname, *args, **kwargs)
>    File "/usr/lib/pymodules/python2.7/openerp/osv/osv.py", line 176, in execute
>      res = self.execute_cr(cr, uid, obj, method, *args, **kw)
>    File "/usr/lib/pymodules/python2.7/openerp/osv/osv.py", line 164, in execute_cr
>      return getattr(object, method)(cr, uid, *args, **kw)
>    File "/usr/lib/pymodules/python2.7/openerp/osv/orm.py", line 4154, in create
>      cr.execute('insert into "'+self._table+'" (id'+upd0+") values ("+str(id_new)+upd1+')', tuple(upd2))
>    File "/usr/lib/pymodules/python2.7/openerp/sql_db.py", line 152, in wrapper
>      return f(self, *args, **kwargs)
>    File "/usr/lib/pymodules/python2.7/openerp/sql_db.py", line 212, in execute
>      res = self._obj.execute(query, params)
>  TransactionRollbackError: could not serialize access due to concurrent update
>  CONTEXT:  SQL statement "SELECT 1 FROM ONLY "public"."res_users" x WHERE "id" OPERATOR(pg_catalog.=) $1 FOR SHARE OF x"
> 
>  2012-06-12 17:17:33,831 1368 ERROR openerp openerp.netsvc: could not serialize access due to concurrent update
>  CONTEXT:  SQL statement "SELECT 1 FROM ONLY "public"."res_users" x WHERE "id" OPERATOR(pg_catalog.=) $1 FOR SHARE OF x"
> 
>  2012-06-12 17:17:33,843 1369 ERROR openerp openerp.sql_db: bad query: insert into "res_partner" (id,"customer","lang","name","color","employee","company_id","supplier","active",create_uid,create_date) values (44647,'True','en_US','Partner - 1 ',0,'False',1,'False','True',1,(now() at time zone 'UTC'))
>  Traceback (most recent call last):
>    File "/usr/lib/pymodules/python2.7/openerp/sql_db.py", line 212, in execute
>      res = self._obj.execute(query, params)
>  TransactionRollbackError: could not serialize access due to concurrent update
>  CONTEXT:  SQL statement "SELECT 1 FROM ONLY "public"."res_users" x WHERE "id" OPERATOR(pg_catalog.=) $1 FOR SHARE OF x"
> 
>  2012-06-12 17:17:33,847 1369 ERROR openerp openerp.osv.osv: Uncaught exception
>  Traceback (most recent call last):
>    File "/usr/lib/pymodules/python2.7/openerp/osv/osv.py", line 121, in wrapper
>      return f(self, dbname, *args, **kwargs)
>    File "/usr/lib/pymodules/python2.7/openerp/osv/osv.py", line 176, in execute
>      res = self.execute_cr(cr, uid, obj, method, *args, **kw)
>    File "/usr/lib/pymodules/python2.7/openerp/osv/osv.py", line 164, in execute_cr
>      return getattr(object, method)(cr, uid, *args, **kw)
>    File "/usr/lib/pymodules/python2.7/openerp/osv/orm.py", line 4154, in create
>      cr.execute('insert into "'+self._table+'" (id'+upd0+") values ("+str(id_new)+upd1+')', tuple(upd2))
>    File "/usr/lib/pymodules/python2.7/openerp/sql_db.py", line 152, in wrapper
>      return f(self, *args, **kwargs)
>    File "/usr/lib/pymodules/python2.7/openerp/sql_db.py", line 212, in execute
>      res = self._obj.execute(query, params)
>  TransactionRollbackError: could not serialize access due to concurrent u2012-06-12 17:17:33,845 1371 ERROR openerp openerp.sql_db: bad query: insert into "res_partner" (id,"customer","lang","name","color","employee","company_id","supplier","active",create_uid,create_date) values (44648,'True','en_US','Partner - 1 ',0,'False',1,'False','True',1,(now() at time zone 'UTC'))
>  Traceback (most recent call last):
>    File "/usr/lib/pymodules/python2.7/openerp/sql_db.py", line 212, in execute
>      res = self._obj.execute(query, params)
>  TransactionRollbackError: could not serialize access due to concurrent update
>  CONTEXT:  SQL statement "SELECT 1 FROM ONLY "public"."res_users" x WHERE "id" OPERATOR(pg_catalog.=) $1 FOR SHARE OF x"
> 
>  2012-06-12 17:17:33,853 1371 ERROR openerp openerp.osv.osv: Uncaught exception
>  Traceback (most recent call last):
>    File "/usr/lib/pymodules/python2.7/openerp/osv/osv.py", line 121, in wrapper
>      return f(self, dbname, *args, **kwargs)
>    File "/usr/lib/pymodules/python2.7/openerp/osv/osv.py", line 176, in execute
>      res = self.execute_cr(cr, uid, obj, method, *args, **kw)
>    File "/usr/lib/pymodules/python2.7/openerp/osv/osv.py", line 164, in execute_cr
>      return getattr(object, method)(cr, uid, *args, **kw)
>    File "/usr/lib/pymodules/python2.7/openerp/osv/orm.py", line 4154, in create
>      cr.execute('insert into "'+self._table+'" (id'+upd0+") values ("+str(id_new)+upd1+')', tuple(upd2))
>    File "/usr/lib/pymodules/python2.7/openerp/sql_db.py", line 152, in wrapper
>      return f(self, *args, **kwargs)
>    File "/usr/lib/pymodules/python2.7/openerp/sql_db.py", line 212, in execute
>      res = self._obj.execute(query, params)
>  TransactionRollbackError: could not serialize access due to concurrent update
>  CONTEXT:  SQL statement "SELECT 1 FROM ONLY "public"."res_users" x WHERE "id" OPERATOR(pg_catalog.=) $1 FOR SHARE OF x"
> 
>  2012-06-12 17:17:33,854 1369 ERROR openerp openerp.netsvc: could not serialize access due to concurrent update
>  CONTEXT:  SQL statement "SELECT 1 FROM ONLY "public"."res_users" x WHERE "id" OPERATOR(pg_catalog.=) $1 FOR SHARE OF x"
> 
>  pdate
>  CONTEXT:  SQL statement "SELECT 1 FROM ONLY "public"."res_users" x WHERE "id" OPERATOR(pg_catalog.=) $1 FOR SHARE OF x"
> 
>  2012-06-12 17:17:33,855 1371 ERROR openerp openerp.netsvc: could not serialize access due to concurrent update
>  CONTEXT:  SQL statement "SELECT 1 FROM ONLY "public"."res_users" x WHERE "id" OPERATOR(pg_catalog.=) $1 FOR SHARE OF x"
> 
>  2012-06-12 17:17:33,895 1370 ERROR openerp openerp.sql_db: bad query: SELECT id from res_users
>                            WHERE login='admin' AND password='admin'
>                                  AND active FOR UPDATE NOWAIT
>  Traceback (most recent call last):
>    File "/usr/lib/pymodules/python2.7/openerp/sql_db.py", line 212, in execute
>      res = self._obj.execute(query, params)
>  OperationalError: could not obtain lock on row in relation "res_users"
> 
> To manage notifications about this bug go to:
> https://bugs.launchpad.net/openobject-server/+bug/1013223/+subscriptions

-- 
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https://bugs.launchpad.net/bugs/1013223

Title:
  concurrent users over xmlrpc

Status in OpenERP Server:
  New

Bug description:
  Setup:

  1 x ubuntu 12.04 LTS server (all updates applied)
  python 2.7.3
  postgresql 9.1
  openerp 6.1

  We wanted to run some load tests based on the simple create_partner.py
  example that everyone uses. When we put 100 concurrent users, logging
  in and creating 100 partners (one at a time) using JMeter we get some
  errors:

  2012-06-12 19:51:42,843 2210 DEBUG ? openerp.sql_db: ConnectionPool(used=0/count=64/max=64) Put connection to 'host=localhost port=5432 user=openerp password=xxxxxxx dbname=openerp' in pool
  2012-06-12 19:51:42,843 2210 ERROR ? openerp.osv.osv: Uncaught exception
  Traceback (most recent call last):
    File "/usr/lib/pymodules/python2.7/openerp/osv/osv.py", line 121, in wrapper
      return f(self, dbname, *args, **kwargs)
    File "/usr/lib/pymodules/python2.7/openerp/osv/osv.py", line 176, in execute
      res = self.execute_cr(cr, uid, obj, method, *args, **kw)
    File "/usr/lib/pymodules/python2.7/openerp/osv/osv.py", line 164, in execute_cr
      return getattr(object, method)(cr, uid, *args, **kw)
    File "/usr/lib/pymodules/python2.7/openerp/osv/orm.py", line 4154, in create
      cr.execute('insert into "'+self._table+'" (id'+upd0+") values ("+str(id_new)+upd1+')', tuple(upd2))
    File "/usr/lib/pymodules/python2.7/openerp/sql_db.py", line 152, in wrapper
      return f(self, *args, **kwargs)
    File "/usr/lib/pymodules/python2.7/openerp/sql_db.py", line 212, in execute
      res = self._obj.execute(query, params)
  TransactionRollbackError: could not serialize access due to concurrent update
  CONTEXT:  SQL statement "SELECT 1 FROM ONLY "public"."res_users" x WHERE "id" OPERATOR(pg_catalog.=) $1 FOR SHARE OF x"
  2012-06-12 19:51:42,844 2210 ERROR ? openerp.netsvc: could not serialize access due to concurrent update

  After seeing this error I decided to update the db_maxconn property to
  1000, to ensure you have enough connections for the test. But I still
  see errors like the one below:

  2012-06-12 19:57:14,811 6327 DEBUG ? openerp.sql_db: ConnectionPool(used=19/count=85/max=1000) Put connection to 'host=localhost port=5432 user=openerp password=xxxxxxx dbname=openerp' in pool
  2012-06-12 19:57:14,811 6327 ERROR ? openerp.netsvc: Object Error
  Object res.partner doesn't exist

  2012-06-12 20:20:26,636 15119 ERROR ? openerp.sql_db: bad query: SELECT id from res_users
                            WHERE login='admin' AND password='admin'
                                  AND active FOR UPDATE NOWAIT
  Traceback (most recent call last):
    File "/usr/lib/pymodules/python2.7/openerp/sql_db.py", line 212, in execute
      res = self._obj.execute(query, params)
  OperationalError: could not obtain lock on row in relation "res_users"

  2012-06-12 20:20:26,745 15119 ERROR ? openerp.sql_db: bad query: insert into "res_partner" (id,"customer","lang","name","color","employee","company_id","supplier","active",create_uid,create_date) values (43536,'True','en_US','Partner - 1 ',0,'False',1,'False','True',1,(now() at time zone 'UTC'))
  Traceback (most recent call last):
    File "/usr/lib/pymodules/python2.7/openerp/sql_db.py", line 212, in execute
      res = self._obj.execute(query, params)
  TransactionRollbackError: could not serialize access due to concurrent update

  2012-06-12 20:20:26,779 15119 ERROR ? openerp.sql_db: bad query: insert into "res_partner" (id,"customer","lang","name","color","employee","company_id","supplier","active",create_uid,create_date) values (43537,'True','en_US','Partner - 1 ',0,'False',1,'False','True',1,(now() at time zone 'UTC'))
  Traceback (most recent call last):
    File "/usr/lib/pymodules/python2.7/openerp/sql_db.py", line 212, in execute
      res = self._obj.execute(query, params)
  TransactionRollbackError: could not serialize access due to concurrent update

  Please find attached the JMeter file you can use to launch the test.
  You will need to change the IP addresses, admin account/password and
  database probably.

  The test environment consists of one box with Ubuntu 12 LTS Server with Postgres 9.1 and OpenERP 6.1 (CRM + Employee Directory modules + demo data). 
  	/usr/bin/openerp-server --db_user=openerp --db_password=openerp --db_host=localhost --db_port=5432 --no-database-list --log-sq --db_maxconn=1000

  Same test with gunicorn sync (no gevent). Please find attached the
  gunicorn configuration. Please look at this well. There could be
  concurrency issues with some of the underlying SQL statements.

  2012-06-12 17:17:33,826 1368 ERROR openerp openerp.sql_db: bad query: insert into "res_partner" (id,"customer","lang","name","color","employee","company_id","supplier","active",create_uid,create_date) values (44646,'True','en_US','Partner - 1 ',0,'False',1,'False','True',1,(now() at time zone 'UTC'))
  Traceback (most recent call last):
    File "/usr/lib/pymodules/python2.7/openerp/sql_db.py", line 212, in execute
      res = self._obj.execute(query, params)
  TransactionRollbackError: could not serialize access due to concurrent update
  CONTEXT:  SQL statement "SELECT 1 FROM ONLY "public"."res_users" x WHERE "id" OPERATOR(pg_catalog.=) $1 FOR SHARE OF x"

  2012-06-12 17:17:33,827 1368 ERROR openerp openerp.osv.osv: Uncaught exception
  Traceback (most recent call last):
    File "/usr/lib/pymodules/python2.7/openerp/osv/osv.py", line 121, in wrapper
      return f(self, dbname, *args, **kwargs)
    File "/usr/lib/pymodules/python2.7/openerp/osv/osv.py", line 176, in execute
      res = self.execute_cr(cr, uid, obj, method, *args, **kw)
    File "/usr/lib/pymodules/python2.7/openerp/osv/osv.py", line 164, in execute_cr
      return getattr(object, method)(cr, uid, *args, **kw)
    File "/usr/lib/pymodules/python2.7/openerp/osv/orm.py", line 4154, in create
      cr.execute('insert into "'+self._table+'" (id'+upd0+") values ("+str(id_new)+upd1+')', tuple(upd2))
    File "/usr/lib/pymodules/python2.7/openerp/sql_db.py", line 152, in wrapper
      return f(self, *args, **kwargs)
    File "/usr/lib/pymodules/python2.7/openerp/sql_db.py", line 212, in execute
      res = self._obj.execute(query, params)
  TransactionRollbackError: could not serialize access due to concurrent update
  CONTEXT:  SQL statement "SELECT 1 FROM ONLY "public"."res_users" x WHERE "id" OPERATOR(pg_catalog.=) $1 FOR SHARE OF x"

  2012-06-12 17:17:33,831 1368 ERROR openerp openerp.netsvc: could not serialize access due to concurrent update
  CONTEXT:  SQL statement "SELECT 1 FROM ONLY "public"."res_users" x WHERE "id" OPERATOR(pg_catalog.=) $1 FOR SHARE OF x"

  2012-06-12 17:17:33,843 1369 ERROR openerp openerp.sql_db: bad query: insert into "res_partner" (id,"customer","lang","name","color","employee","company_id","supplier","active",create_uid,create_date) values (44647,'True','en_US','Partner - 1 ',0,'False',1,'False','True',1,(now() at time zone 'UTC'))
  Traceback (most recent call last):
    File "/usr/lib/pymodules/python2.7/openerp/sql_db.py", line 212, in execute
      res = self._obj.execute(query, params)
  TransactionRollbackError: could not serialize access due to concurrent update
  CONTEXT:  SQL statement "SELECT 1 FROM ONLY "public"."res_users" x WHERE "id" OPERATOR(pg_catalog.=) $1 FOR SHARE OF x"

  2012-06-12 17:17:33,847 1369 ERROR openerp openerp.osv.osv: Uncaught exception
  Traceback (most recent call last):
    File "/usr/lib/pymodules/python2.7/openerp/osv/osv.py", line 121, in wrapper
      return f(self, dbname, *args, **kwargs)
    File "/usr/lib/pymodules/python2.7/openerp/osv/osv.py", line 176, in execute
      res = self.execute_cr(cr, uid, obj, method, *args, **kw)
    File "/usr/lib/pymodules/python2.7/openerp/osv/osv.py", line 164, in execute_cr
      return getattr(object, method)(cr, uid, *args, **kw)
    File "/usr/lib/pymodules/python2.7/openerp/osv/orm.py", line 4154, in create
      cr.execute('insert into "'+self._table+'" (id'+upd0+") values ("+str(id_new)+upd1+')', tuple(upd2))
    File "/usr/lib/pymodules/python2.7/openerp/sql_db.py", line 152, in wrapper
      return f(self, *args, **kwargs)
    File "/usr/lib/pymodules/python2.7/openerp/sql_db.py", line 212, in execute
      res = self._obj.execute(query, params)
  TransactionRollbackError: could not serialize access due to concurrent u2012-06-12 17:17:33,845 1371 ERROR openerp openerp.sql_db: bad query: insert into "res_partner" (id,"customer","lang","name","color","employee","company_id","supplier","active",create_uid,create_date) values (44648,'True','en_US','Partner - 1 ',0,'False',1,'False','True',1,(now() at time zone 'UTC'))
  Traceback (most recent call last):
    File "/usr/lib/pymodules/python2.7/openerp/sql_db.py", line 212, in execute
      res = self._obj.execute(query, params)
  TransactionRollbackError: could not serialize access due to concurrent update
  CONTEXT:  SQL statement "SELECT 1 FROM ONLY "public"."res_users" x WHERE "id" OPERATOR(pg_catalog.=) $1 FOR SHARE OF x"

  2012-06-12 17:17:33,853 1371 ERROR openerp openerp.osv.osv: Uncaught exception
  Traceback (most recent call last):
    File "/usr/lib/pymodules/python2.7/openerp/osv/osv.py", line 121, in wrapper
      return f(self, dbname, *args, **kwargs)
    File "/usr/lib/pymodules/python2.7/openerp/osv/osv.py", line 176, in execute
      res = self.execute_cr(cr, uid, obj, method, *args, **kw)
    File "/usr/lib/pymodules/python2.7/openerp/osv/osv.py", line 164, in execute_cr
      return getattr(object, method)(cr, uid, *args, **kw)
    File "/usr/lib/pymodules/python2.7/openerp/osv/orm.py", line 4154, in create
      cr.execute('insert into "'+self._table+'" (id'+upd0+") values ("+str(id_new)+upd1+')', tuple(upd2))
    File "/usr/lib/pymodules/python2.7/openerp/sql_db.py", line 152, in wrapper
      return f(self, *args, **kwargs)
    File "/usr/lib/pymodules/python2.7/openerp/sql_db.py", line 212, in execute
      res = self._obj.execute(query, params)
  TransactionRollbackError: could not serialize access due to concurrent update
  CONTEXT:  SQL statement "SELECT 1 FROM ONLY "public"."res_users" x WHERE "id" OPERATOR(pg_catalog.=) $1 FOR SHARE OF x"

  2012-06-12 17:17:33,854 1369 ERROR openerp openerp.netsvc: could not serialize access due to concurrent update
  CONTEXT:  SQL statement "SELECT 1 FROM ONLY "public"."res_users" x WHERE "id" OPERATOR(pg_catalog.=) $1 FOR SHARE OF x"

  pdate
  CONTEXT:  SQL statement "SELECT 1 FROM ONLY "public"."res_users" x WHERE "id" OPERATOR(pg_catalog.=) $1 FOR SHARE OF x"

  2012-06-12 17:17:33,855 1371 ERROR openerp openerp.netsvc: could not serialize access due to concurrent update
  CONTEXT:  SQL statement "SELECT 1 FROM ONLY "public"."res_users" x WHERE "id" OPERATOR(pg_catalog.=) $1 FOR SHARE OF x"

  2012-06-12 17:17:33,895 1370 ERROR openerp openerp.sql_db: bad query: SELECT id from res_users
                            WHERE login='admin' AND password='admin'
                                  AND active FOR UPDATE NOWAIT
  Traceback (most recent call last):
    File "/usr/lib/pymodules/python2.7/openerp/sql_db.py", line 212, in execute
      res = self._obj.execute(query, params)
  OperationalError: could not obtain lock on row in relation "res_users"

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References

[Bug 1013223] [NEW] concurrent users over xmlrpc
From: Marcos Mendez, 2012-06-14
[Bug 1013223] Re: concurrent users over xmlrpc
From: Amit Parik (OpenERP), 2012-06-18