On 03/07/17 13:01, Dmitry Telegin wrote:
Hi Marek,
Thanks for the hint, looks very reasonable. I think the
PostMigrationEvent approach is more suitable for heavyweight stuff
like checking and creating database entries etc., while lazyInit is
good for more lightweight tasks like opening connections etc.
However, there's an interesting case when the postInit method is
called on hot (re)deploy (no PostMigrationEvent obviously) *and* some
heavyweight stuff needs to be done right away. (ATM postInit is not
called on hot deploy, but I hope that will be fixed soon, see
KEYCLOAK-5131 and PR #4282.)
Luckily, in this case transactions just work, so everything could be
done straightforwardly. The only question is how to distinguish
between server startup and hot (re)deploy inside postInit. There are
some indirect signs like thread name, presence/absence of specific
JNDI entries etc., but this seems hacky. Any suggestions?
I don't have any good
suggestions besides other workaround. You can
create provider, which will be deployed "statically" and will track
whether PostMigrationEvent was already sent. Since it is deployed at
startup like builtin providers, the event will be always there. The
"dynamic" providers will be then able either to ask this provider or
listen to the event.
Maybe we need to have another lifecycle method on ProviderFactory for
this usecase, not sure..
Marek
Cheers,
Dmitry
> Hi,
>
> I think it's not good to directly start transactions from postInit.
> Among the issues you mentioned, various initial steps (eg. migration
> from previous version, export/import) may not be yet finished at this
> stage. Probably you can either:
> - Register listener for PostMigrationEvent in your postInit. See the
>
testsuite/integration-arquillian/servers/auth-server/services/testsuite-providers/src/main/java/org/keycloak/testsuite/authentication/PushButtonAuthenticator.java
>
> for inspiration.
> - Use the pattern with "lazyInit" like for example here
>
https://github.com/keycloak/keycloak/blob/master/model/jpa/src/main/java/...
>
> , which is called 1st time before your provider is actually needed.
>
> Maybe we can improve by provide more callback methods to
> ProviderFactory/Provider to avoid the lazyInit pattern directly in
> providers, but rather integrate it better with the Provider framework.
> But for now, I think that some of the workaround above should work for
> you IMO.
>
> Marek
>
> On 03/07/17 03:50, Dmitry Telegin wrote:
>>
https://issues.jboss.org/browse/KEYCLOAK-5132
>>
>> Meanwhile I've found a workaround - just run a transaction in a new
>> thread. However, this should be a "managed thread" - see issue details
>> & comments for more info.
>>
>> В Wed, 28/06/2017 в 21:18 +0300, Dmitry Telegin пишет:
>>> Hi,
>>>
>>> (TL;DR) if a KeycloakTransaction is opened from
>>> ProviderFactory::postInit, sometimes the transaction is already
>>> active
>>> on the underlying
>>> org.jboss.jca.adapters.jdbc.local.LocalManagedConnection, which leads
>>> to errors.
>>>
>>> (full version) I think it's essential for the providers to be able to
>>> access realm data in postInit(). For that, a transaction is required;
>>> using KeycloakModelUtils.runJobInTransaction() is a convenient method
>>> to do that:
>>>
>>> @Override
>>> public void postInit(KeycloakSessionFactory factory) {
>>> KeycloakModelUtils.runJobInTransaction(factory,
>>> (KeycloakSession session) -> {
>>> List<RealmModel> realms = session.realms().getRealms();
>>> // do stuff
>>> });
>>> }
>>>
>>> When such a provider is deployed, in about half of cases Keycloak
>>> fails
>>> to start due to the following exception:
>>>
>>> java.sql.SQLException: IJ031017: You cannot set autocommit during a
>>> managed transaction
>>>
>>> (see full stacktrace here
https://pastebin.com/ETtPqXQk)
>>>
>>> I've managed to track it down to something that looks like
>>> transaction
>>> clash over a single instance of
>>> org.jboss.jca.adapters.jdbc.local.LocalManagedConnection. What
>>> happens
>>> is that the two treads at the same time begin two
>>> KeycloakTransactions
>>> which end up with the same instance of LocalManagedConnection. The
>>> above exception results from the second begin() call.
>>>
>>> There's a system property called
"ironjacamar.jdbc.ignoreautocommit"
>>> that allows to ignore the situation, but I think it's dangerous
>>> because
>>> it doesn't eliminate the transaction clash, just suppresses the
>>> check.
>>> If I'm not mistaken, this began to happen around Keycloak 2.2.x,
>>> which
>>> coincides with the changes to Keycloak transaction management. That
>>> said, do I need now some additional transaction coordination with the
>>> rest of Keycloak, or is it a bug? If former, how do I do that? If
>>> latter, how do we fix it?
>>>
>>> I hope we'll sort it out, since the ability to access the data at
>>> every
>>> phase of provider's lifecycle seems something fundamental to me.
>>>
>>> Regards,
>>> Dmitry
>>> _______________________________________________
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>>>
https://lists.jboss.org/mailman/listinfo/keycloak-user
>>
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