topic Re: runtimeService.getVariables requires a ReadW in Alfresco Archive

runtimeService.getVariables requires a ReadW

billy_mcdonagh — Tue, 20 Oct 2015 10:18:10 GMT

Hi, I'm using Activiti 5.1.4 with Spring 4.1.5.RELEASE and Hibernate 4.1.9.Final and I'm getting the following issue 'cannot execute UPDATE in a read-only transaction' (stacktrace below) when calling the RuntimeService.getVariables() method. My service method containing the call to the RuntimeServic

Re: runtimeService.getVariables requires a ReadW

jbarrez — Tue, 20 Oct 2015 17:31:05 GMT

No, the getVariables() should do any update. But the fact it's a byteArray … could it be you have Serialized java objects as variables? That might explain it.
Out of curiosity: whats the use for demarcating your transactions so strictly?

Re: runtimeService.getVariables requires a ReadW

billy_mcdonagh — Thu, 22 Oct 2015 09:15:18 GMT

Thanks for your quick response 🙂

Yes we do have Java objects as variables so this makes sense.
Probably a silly question but what updates would activity be flushing for a call to getVariables()?

The reason we have the transactions so strict is because according to the Spring Documentation (http://docs.spring.io/spring/docs/current/spring-framework-reference/html/transaction.html#transaction-strategies) if using Hibernate setting a transaction as read-only allows it to do some optimisation
….
Read-only status: A read-only transaction can be used when your code reads but does not modify data. Read-only transactions can be a useful optimization in some cases, such as when you are using Hibernate.
…..

Also it is useful if another developer wrongly modifies a service method that is understood to only perform readonly actions. If marked as readonly an exception will be thrown which will hopefully highlight the issue.

Thanks.
Billy.

Re: runtimeService.getVariables requires a ReadW

jbarrez — Wed, 28 Oct 2015 18:50:04 GMT

> Probably a silly question but what updates would activity be flushing for a call to getVariables()?

Not a silly question, I was pondering about that myself 😉 I guess for Java object serialization some 'touching' is going on, even if it's just a 'get'.

Ok, thanks for the readonly explanation. I've never saw it being used in practice.