Nicolas,
Your proposal for a new method like,
"SequenceUtil.getNextSequence(String
key, long staggerMax)" sounds like what I am proposing. Would the
"staggerMax" parameter set the next range of sequence IDs? For
example:
Before calling "getNextSequence" method"
SeqName: MySequence
SeqId: 1000
Now call your method: SequenceUtil.getNextSequence("MySequence", 1500)
After the call the SequenceValueItem record has the following:
SeqName: MySequence
SeqId: 2501
We ran into some performance problems for some of our entities
(OrderItem,
InventoryItem, etc) when the application servers were generating
sequenceIds
for these entities and the default sequence-bank-size was only 10.
The
process of getting a new range of sequence IDs from the database is a
locking process and we had multiple servers trying to perform the same
function. This was creating table locks during high loads.
In the entity definition you can specify the "sequence-bank-size"
like so:
<entity entity-name=*"ProductSurveyResource" *package-name=*
"org.ofbiz.product.survey" *sequence-bank-size=*"1000"*>
but we couldn't find a way to specify the bank size for non-entity
related
sequence IDs. We also use the "sequence-id" simple method a lot
but this
only works for entity related sequences and doesn't have a
parameter to
set
the "staggerMax".
My proposal was simply to add a new column to the SequenceValueItem
table
called "sequenceBankSize" (or something like that). Using my example
above
the SequenceValueItem table might look like the following:
column names: SeqName, SeqId, SeqBankSize
record values: MySequence, 1000, 1500
Then when the you used the
SequenceUtil.getNextSequence("MySequence") or
the
simple method "sequence-id" for the first time the sequencer would
update
the SequenceValueItem table as follows:
MySequence, 2501, 1500
Subsequent "getNextSequence" calls would continue to return unique IDs
without hitting the database until the bank of 1500 IDs was used up
and
then
the above process would continue again.
For us the key points we would like to see for the sequencer are as
follows:
1. Ability to use non-entity related sequences by just providing a
sequence
name.
2. Ability to configure the sequence bank size so we can adjust the
frequency for database updates.
3. Any APIs for the sequence util should be available via simple
methods. We could provide a patch for the simple method support
for the
new
utils if needed.
Thanks,
Brett
On Thu, Dec 24, 2009 at 8:52 AM, Nicolas Malin <
malin.nico...@librenberry.net> wrote:
After some reflection on this subject, I arrive to :
getNextSeqId is use normaly to get an single id that identify an
entity : Invoice.invoiceId, Order.orderId, Party.partyId etc ...
It's easier to remove the problematic instruction but bypasses
getNextSeqId purpose.
For multiple sequence on Entity I suggest to create new function on
delegator : getNextSequence (String entityName, String diff, long
staggerMax) that manage sequence as getNextSeqId but analyse just the
validity of entityName and generate sequenceValueId :
entityName.diff.
As this, Delegator continue to work only on entity and not use for
other
not in relation with entitymodel.
For sequence not in relation with entity, I can extend
sequenceUtil to
have a function SequenceUtil.getNextSequence(String key, long
staggerMax).
Brett can you give me an example for your proposal ? I don't really
understand your improvement.
If you wait to read, Have a nice end year ;)
Nicolas
Le mercredi 23 décembre 2009 à 13:49 -0700, Brett Palmer a écrit :
> I confirmed that if you use the delegator.getNextSeqId() you
will get
an
exception every time it is used with a complaint that an entity
doesn't
exist for the sequence you requested. It does give still
generate an ID
but
the exception is a little concerning when you are running in a
production
environment. This exception probably isn't intended but is a
consequence
of
the call to look for the entity name.
I would prefer we just outputted a warning log and not threw an
exception.
Another request for the sequence generator is the ability to
specify the
gap
between the next sequence ID update. This can be configured in the
entity
engine but only for those IDs that have a corresponding entity.
If you
try
to use a generic sequencer with no attached entity the default is 10
which
can be low for a production environment with multiple servers.
Could we
add
a column to the SequenceValueItem to include the next increment
value?
Brett
Here is the stack trace:
---- exception report
----------------------------------------------------------
Error getting entity definition from model
Exception: org.ofbiz.entity.GenericModelException
Message: Could not find definition for entity name DummySequence
---- stack trace
---------------------------------------------------------------
org.ofbiz.entity.GenericModelException: Could not find definition
for
entity
name DummySequence
org.ofbiz.entity.model.ModelReader.getModelEntity(ModelReader.java:451)
org.ofbiz.entity.DelegatorImpl.getModelEntity(DelegatorImpl.java:1544)
org.ofbiz.entity.DelegatorImpl.getNextSeqIdLong(DelegatorImpl.java:1693)
org.ofbiz.entity.DelegatorImpl.getNextSeqId(DelegatorImpl.java:1655)
org.ofbiz.entity.DelegatorImpl.getNextSeqId(DelegatorImpl.java:1651)
com.automationgroups.pe.util.InventoryContainer.start(InventoryContainer.java:27)
org.ofbiz.base.container.ContainerLoader.start(ContainerLoader.java:101)
org.ofbiz.base.start.Start.startStartLoaders(Start.java:272)
org.ofbiz.base.start.Start.startServer(Start.java:322)
org.ofbiz.base.start.Start.start(Start.java:326)
org.ofbiz.base.start.Start.main(Start.java:409)
--------------------------------------------------------------------------------
2009-12-23 13:29:07,218 (main) [ SequenceUtil.java:236:WARN ]
[SequenceUtil.SequenceBank.fillBank] first select failed: will
try to
add
new row, result set was empty for sequence [DummySequence]
Used SQL: SELECT SEQ_ID FROM SEQUENCE_VALUE_ITEM WHERE
SEQ_NAME='DummySequence'
Thread Name is: main:Thread[main,5,main]
2009-12-23 13:29:07,312 (main) [ SequenceUtil.java:341:INFO ] Got
bank
of sequenced IDs for [DummySequence]; curSeqId=10000,
maxSeqId=10010,
bankSize=10
2009-12-23 13:29:07,312 (main) [ InventoryContainer.java:28 :INFO
] Here
is
the sample sequence Id: 10000
2009-12-23 13:29:07,343 (main) [ GenericDispatcher.java:61 :INFO ]
Creating
new dispatcher [RMIDispatcher] (main)
On Wed, Dec 23, 2009 at 12:54 PM, Scott Gray <
scott.g...@hotwaxmedia.com
wrote:
It looks to me as though an exception is being logged rather than
thrown,
is the id still being generated?
Regards
Scott
HotWax Media
http://www.hotwaxmedia.com
On 24/12/2009, at 3:31 AM, Nicolas Malin wrote:
Hi all,
It's possible that this subject has been already discussed here
but I
don't find any trace in the archives.
A long time ago, I used delegator.getNextSeqId to use multiple
sequences
in an entity like invoice (SALES, PURCHASE, ...).
Example : in France we use a sequence for all invoiceType and I
call
the
delegator this way :
invoiceId = delegator.getNextSeqId("Invoice." + invoiceTypeId);
To have :
for sales : VE10000, VE10001, VE10002, ...
for purchases : AC10000, AC10001, AC10002, ...
Now when using this, GenericDelegator throws an exception :
"Could not
find definition for entity name Invoice.PURCHASE_INVOICE"
I checked the code (GenericDelegotor.java:3049 on trunk) and
found :
// might be null, but will usually match the entity name
ModelEntity seqModelEntity =
this.getModelEntity(seqName);
I suppose that there are some reasons to check the seqName as an
entityName but I don't understand why.
To manage many sequences for one entity, do you use directly the
sequenceUtil ?
Is it possible to add an escape case before checking entity (as
add
test
if we find a point) ? Or extend getNextSeqId to manage prefix/suffix
parameters ?
Nicolas
--
Nicolas MALIN
Consultant
Tél : 06.17.66.40.06
Site projet : http://www.neogia.org/
-------
Société LibrenBerry
Tél : 02.48.02.56.12
Site : http://www.librenberry.net/
--
Nicolas MALIN
Consultant
Tél : 06.17.66.40.06
Site projet : http://www.neogia.org/
-------
Société LibrenBerry
Tél : 02.48.02.56.12
Site : http://www.librenberry.net/
