What concerns me about that approach is liveness. The approach I had in
mind was (pseudo code):
while updating
do calculations
update entity value
was original value updated?
if yes, exit while
continue while
Adrian Crum
Sandglass Software
www.sandglass-software.com
On 8/6/2014 3:44 PM, Brett Palmer wrote:
We have run into this problem in the past with the inventory and other
entities when running multiple application servers under high load. We
worked around this issue by creating a custom class that gets the
Connection from the entity engine. Then we built a custom JDBC query to do
a SELECT for UPDATE that guarantees no other process can update the record
until the transaction is committed.
I'm not sure this is the recommended way to do this in ofbiz but it worked
for us in isolated situations.
Brett
On Wed, Aug 6, 2014 at 12:31 AM, Yaocl <chunlin...@gmail.com> wrote:
I can only consider a solution use SELECT FOR UPDATE, lock the
inventory item then SELECT ... sum(...) FROM inventory_item_detail
GROUP BY ...., then update the inventory item. But it seems
EntityEngine not support FOR UPDATE.
--
YaoCL
On Wed, Aug 6, 2014 at 1:41 PM, Adrian Crum
<adrian.c...@sandglass-software.com> wrote:
This has been discussed on the dev mailing list, and there are differing
opinions. I agree this is a bug and should be fixed, but others believe
it
is highly unlikely two people will be modifying the same invoice at the
same
time - so it is not a problem.
Adrian Crum
Sandglass Software
www.sandglass-software.com
On 8/6/2014 3:01 AM, YaoCL wrote:
Hi,
When create a new InventoryItemDetail the InventoryItem will be updated
by
eeca. But If two threads create InventoryItemDetails simultaneously.
Because
we use ReadCommitted Isolation level, Neither will see
InventoryItemDetails
created by other threads before transaction commit.
updateInventoryItemFromDetail service will get incorrect qoh, and
InventoryItem will be updated. Two threads will all be committed
successfully.
I can confirm the behavior by set a breakpoint in
org.ofbiz.minilang.method.entityops.StoreValue.exec(MethodContext) to
emulate above process. The result can be checked by this SQL.
select * from inventory_item t1 left join (
select inventory_item_id, sum(quantity_on_hand_diff) as qoh,
sum(available_to_promise_diff) as atp from inventory_item_detail
group by inventory_item_id) t2 on t1.inventory_item_id =
t2.inventory_item_id
where t1.quantity_on_hand_total <> t2.qoh;
—
YaoCL
