Now we are in version 16 Enterprise,

 still i am facing the same problem

RPC_ERROR

Odoo Server Error

Traceback (most recent call last):

  File "/home/odoo/src/odoo/odoo/http.py", line 1633, in _serve_db

    return service_model.retrying(self._serve_ir_http, self.env)

  File "/home/odoo/src/odoo/odoo/service/model.py", line 133, in retrying

    result = func()

  File "/home/odoo/src/odoo/odoo/http.py", line 1660, in _serve_ir_http

    response = self.dispatcher.dispatch(rule.endpoint, args)

  File "/home/odoo/src/odoo/odoo/http.py", line 1864, in dispatch

    result = self.request.registry['ir.http']._dispatch(endpoint)

  File "/home/odoo/src/odoo/odoo/addons/base/models/ir_http.py", line 154, in _dispatch

    result = endpoint(**request.params)

  File "/home/odoo/src/odoo/odoo/http.py", line 697, in route_wrapper

    result = endpoint(self, *args, **params_ok)

  File "/home/odoo/src/odoo/addons/web/controllers/dataset.py", line 46, in call_button

    action = self._call_kw(model, method, args, kwargs)

  File "/home/odoo/src/odoo/addons/web/controllers/dataset.py", line 33, in _call_kw

    return call_kw(request.env[model], method, args, kwargs)

  File "/home/odoo/src/odoo/odoo/api.py", line 468, in call_kw

    result = _call_kw_multi(method, model, args, kwargs)

  File "/home/odoo/src/odoo/odoo/api.py", line 453, in _call_kw_multi

    result = method(recs, *args, **kwargs)

  File "/home/odoo/src/user/sale_base_16/models/sale_approval.py", line 509, in get_approval

    self.action_confirm()

  File "/home/odoo/src/user/sale_base_16/models/sale_approval.py", line 430, in action_confirm

    return super(CustomSaleOrder, self).action_confirm()

  File "/home/odoo/src/user/sale_base_16/models/models.py", line 58, in action_confirm

    rec.name = rec.doc_type_id.sequence_id.next_by_id()

  File "/home/odoo/src/odoo/odoo/addons/base/models/ir_sequence.py", line 274, in next_by_id

    return self._next(sequence_date=sequence_date)

  File "/home/odoo/src/odoo/odoo/addons/base/models/ir_sequence.py", line 263, in _next

    return self._next_do()

  File "/home/odoo/src/odoo/odoo/addons/base/models/ir_sequence.py", line 204, in _next_do

    number_next = _update_nogap(self, self.number_increment)

  File "/home/odoo/src/odoo/odoo/addons/base/models/ir_sequence.py", line 57, in _update_nogap

    self._cr.execute("SELECT number_next FROM %s WHERE id=%%s FOR UPDATE NOWAIT" % self._table, [self.id])

  File "/home/odoo/src/odoo/odoo/sql_db.py", line 321, in execute

    res = self._obj.execute(query, params)

psycopg2.errors.LockNotAvailable: could not obtain lock on row in relation "ir_sequence"

The above server error caused the following client error:

RPC_ERROR: Odoo Server Error

    at makeErrorFromResponse (https://ltindia-ltindia.odoo.com/web/assets/19741-472c7f6/web.assets_backend.min.js:1000:163)

    at XMLHttpRequest. (https://ltindia-ltindia.odoo.com/web/assets/19741-472c7f6/web.assets_backend.min.js:1008:13)

Thats error message caused by postgresql failed to fetch some record because the record wich related to the action but the pgsql still processing (can be write command or etc) by another request at postgresql buffer.


If you use "No Gap" implementation then for a simple way to resolve your issue you can try change the implementation to "Standard"

But if you still require to use "No Gap" implementation maybe you must reconfigure your postgresql server configuration,, or you can optimize your server to speed up the performance

Further read:
https://www.postgresql.org/docs/9.1/explicit-locking.html