Verified in 7.0.0 CR2

I updated the templates that uses postgresql.

apparently to fix the issue in the attached stack trace, a extra conf is needed at database side:

this value need to be higher than 0: max_prepared_transactions
I am not sure if we can configure it at datasource level.

https://access.redhat.com/documentation/en-us/red_hat_jboss_enterprise_application_platform/7.1/html/configuration_guide/datasource_management#vendor_specific_xa_recovery

Apparently the image has the ability to set it: https://github.com/sclorg/postgresql-container/blob/master/src/root/usr/share/container-scripts/postgresql/openshift-custom-postgresql.conf.template#L15

ksuta you can try to add the POSTGRESQL_MAX_PREPARED_TRANSACTIONS env.

Reopened, failing on PostgreSQL DB when I tried to deploy container containing process with timer [1].

[1] https://github.com/kiegroup/kie-cloud-tests/tree/master/test-cloud/test-cloud-remote/src/test/resources/kjars-sources/timer-project

Verification is currently blocked by RHPAM-740.

From my own brief check it seems to work. Will make more tests in Monday.

After a conversation with Maciej and Marian some extra checks will need to be applied, like:
-> make the tx_isolation configurable but default it to TRANSACTION_READ_COMMITTED.
-> both datasources must be XA, maybe force it to be XA even if user specify if to be nonxa.
-> create only one timer service datastore.

KrisVerlaenen Sorry, just saw your note here. Yes; looking into it.

dward-se-jboss can you work (with QE and Maciej) to make sure this gets resolved?

In attachment (DB-timer.zip) you can find standalone reproducer with suggested configuration. It can come handy for local experiments. The reproducer starts 3 WildFly instances with managed Kie servers pointing to same database. It also contains simple test (TimerIT.java) for creating of container with process containing intermediate timer event and starting of several processes in parallel. In the server log (and in console) you can see when the process is started (showing "Before timer") and when the process finished timer event (showing "After timer").
The reproducer can be executed using "mvn clean install" command.