February 2009 - jboss-user - Jboss List Archives

[JBoss jBPM] - Dynamic Fork + External Async WS invocation + problem

by clandestino_bgd

Hi people, in short: My Process: Just after Start state, I have dynamic fork (Action Handler defined on Node, very similar to the one on wiki). In each child I have a Task node, on which event (task-create) I have an ActionHandler which invokes WS asynchronously, by passing taskInstanceId as parameter. When WS finishes the operation, it invokes callback method which ends the task instance. And the problem: When I start the process instance, if I have a significant number of children, it happens that the 1st WS does the callback before all child tokens are generated, which results in NPE when I try to get task instance in callback method. Ok, seems, that new tokens and created task instances are not persisted in DB, but only in memory and this is according to docs, but can I somehow change the default behavior and support the described scenario? Or maybe somebody has an idea how to support "concurrent" WS invocations without explicitely call to each of them? Retrying callback or WS timeout can fix the problem, but this is configurable on WS side, not JBPM. Any idea, much appreciated. best, milan View the original post : http://www.jboss.com/index.html?module=bb&op=viewtopic&p=4206146#4206146 Reply to the post : http://www.jboss.com/index.html?module=bb&op=posting&mode=reply&p=4206146

16 years, 11 months

1
0
0 / 0

[JBoss Cache: Core Edition] - Re: very strange behaviour of jboss cache 1.4.1

by bobbiee

I will try different combinations as you said. Anyway, thanks for helping me find out what is wrong, now its only to find some kind of middle way:) Many thanks to you, bstansberry:) View the original post : http://www.jboss.com/index.html?module=bb&op=viewtopic&p=4206141#4206141 Reply to the post : http://www.jboss.com/index.html?module=bb&op=posting&mode=reply&p=4206141

16 years, 11 months

1
0
0 / 0

[JBoss Cache: Core Edition] - Re: very strange behaviour of jboss cache 1.4.1

by bstansberry＠jboss.com

There's really no way to answer that question; whether caching is beneficial is highly dependent on the details of the application. I always encourage users to load test and benchmark; try different combinations to see what works best. You say "it's inadmissible for me to have clear cache so often, as the entities after are loaded directly from dbs and traffic is incredible, server is very unstable then" so it sounds like you need a solution that avoids invalidating the cache. So is there anything you can do about the fact that "ejb3 queries in cases the entities are not cached are slowing down the operations, especially the load"? Are you annotating properties that don't have to be loaded with @java.persistence.Basic(fetch=LAZY)? View the original post : http://www.jboss.com/index.html?module=bb&op=viewtopic&p=4206139#4206139 Reply to the post : http://www.jboss.com/index.html?module=bb&op=posting&mode=reply&p=4206139

16 years, 11 months

1
0
0 / 0

[JBoss Cache: Core Edition] - Re: very strange behaviour of jboss cache 1.4.1

by bobbiee

Yes, that seems to be the problem:) It looks like not good for me, cause I am working on project where is a lot of traffic. So some of the operations needs to use sql query to perform faster load (especially when loaded entities - huge objects are not ment to be cached) and in the same time, it's inadmissible for me to have clear cache so often, as the entities after are loaded directly from dbs and traffic is incredible, server is very unstable then... Do you think I should switch the code to only use sql queries?? As ejb3 queries in cases the entities are not cached are slowing down the operations, especially the load. View the original post : http://www.jboss.com/index.html?module=bb&op=viewtopic&p=4206138#4206138 Reply to the post : http://www.jboss.com/index.html?module=bb&op=posting&mode=reply&p=4206138

16 years, 11 months

1
0
0 / 0

[JBoss Cache: Core Edition] - Re: Problem when using EJB3EntityTreeCache for caching entit

by bobbiee

Sorry for double post... View the original post : http://www.jboss.com/index.html?module=bb&op=viewtopic&p=4206137#4206137 Reply to the post : http://www.jboss.com/index.html?module=bb&op=posting&mode=reply&p=4206137

16 years, 11 months

1
0
0 / 0

[JBoss Cache: Core Edition] - Re: Problem when using EJB3EntityTreeCache for caching entit

by bobbiee

Hi people, I have exactly the same problem as mihai.ratiu does. As I understand, when I execute native query in my code, the cache gets completely clear?? This is the answer I expected, when I try to remove all native queries and replace it by ejb3 queries, the cache remains full. Does it mean I can't use any native sql queries in my code to keep the cache working normally?? Heh, that's pretty not good as native queries are much more faster and for some operations I just can't use normal queries... Another question is here: How can I replace native queries? View the original post : http://www.jboss.com/index.html?module=bb&op=viewtopic&p=4206136#4206136 Reply to the post : http://www.jboss.com/index.html?module=bb&op=posting&mode=reply&p=4206136

16 years, 11 months

1
0
0 / 0

[JBoss Cache: Core Edition] - Re: Problem when using EJB3EntityTreeCache for caching entit

by bobbiee

Hi people, I have exactly the same problem as mihai.ratiu does. As I understand, when I execute native query in my code, the cache gets completely clear?? This is the answer I expected, when I try to remove all native queries and replace it by ejb3 queries, the cache remains full. Does it mean I can't use any native sql queries in my code to keep the cache working normally?? Heh, that's pretty not good as native queries are much more faster and for some operations I just can't use normal queries... Another question is here: How can I replace native queries? View the original post : http://www.jboss.com/index.html?module=bb&op=viewtopic&p=4206135#4206135 Reply to the post : http://www.jboss.com/index.html?module=bb&op=posting&mode=reply&p=4206135

16 years, 11 months

1
0
0 / 0

[JBoss Cache: Core Edition] - Re: very strange behaviour of jboss cache 1.4.1

by bstansberry＠jboss.com

Yes, see comment I posted a half-hour or so ago on the other thread. If you execute native queries, Hibernate has no way to know what changes you are making in the underlying database, and is forced to aggressively clear the cache to avoid leaving stale data. Same thing applies if you do bulk updates -- i.e. update a bunch of entities that match a where clause -- since Hibernate doesn't know what entities match the where clause. So it is forced to remove all entities of the particular type from the cache. If you query for the entities that match your where clause and then iterate over them making the update one by one, Hibernate knows what entity instance was changed and can update the cache for just that one instance. Of course if your where clause matches a lot of entities, it might be more performant to accept losing the cache contents and do the bulk update. View the original post : http://www.jboss.com/index.html?module=bb&op=viewtopic&p=4206134#4206134 Reply to the post : http://www.jboss.com/index.html?module=bb&op=posting&mode=reply&p=4206134

16 years, 11 months

1
0
0 / 0

[JBoss Cache: Core Edition] - Re: Problem when using EJB3EntityTreeCache for caching entit

by bstansberry＠jboss.com

I had a chance to poke around a bit. In the Hibernate code the only path I see that results in the entire region for an entity being removed from the cache is via the BulkOperationCleanupAction, which gets clears the cache region during tx commit if the tx executed some "bulk operation". Typically that would be the execution of native SQL whereby Hibernate couldn't track when entity instances were affected by the the SQL, forcing the invalidation of everything all instances of the entity. Is your code doing that? View the original post : http://www.jboss.com/index.html?module=bb&op=viewtopic&p=4206133#4206133 Reply to the post : http://www.jboss.com/index.html?module=bb&op=posting&mode=reply&p=4206133

16 years, 11 months

1
0
0 / 0

[JBoss Cache: Core Edition] - Re: very strange behaviour of jboss cache 1.4.1

by bobbiee

Now after lots and lots of debugging I can confirm that the cache becomes empty after I user createNativeQuery() method of the EntityManager class. When I replace it by createQuery() method, cache looks like fine, without suddenly going to 0. Could this be the reason?? View the original post : http://www.jboss.com/index.html?module=bb&op=viewtopic&p=4206128#4206128 Reply to the post : http://www.jboss.com/index.html?module=bb&op=posting&mode=reply&p=4206128

16 years, 11 months

1
0
0 / 0

2026

2025

2024

2023

2022

2021

2020

2019

2018

2017

2016

2015

2014

2013

2012

2011

2010

2009

2008

2007

2006

jboss-user February 2009