Hi there,
I was wondering if you are supporting amazon aurora postgres or mysql variant yet. I didn’t find it in the supported databases, but if we do not use any RDS Multi-AZ feature I thought that it would work, but I wanted to make sure that it’s supported…
Thanks in advance!
Cheers,
Michael
Hi Michael,
I echo your question re Aurora, it would be nice to know if this can be a recognized tech stack…
Im curious about your motivation to not use Multi-AZ? From my perspective, its one of the compelling features of RDS in a production environment…
From the camunda docs, there is a paragraph re DB clusters;
Clustered or replicated databases are supported given the following conditions. The communication between Camunda BPM and the database cluster has to match with the corresponding non-clustered / non-replicated configuration. It is especially important that the configuration of the database cluster guarantees the equivalent behavior of READ-COMMITTED isolation level.
My understanding of RDS is it uses low level synchronous block level replication (except for MSSQL Server). Hence the multi-AZ feature should be transparent to the DBMS transaction layer. Given RDS supports read committed even in Multi-AZ, on paper it should just work.
I note however that RDS Multi-AZ uses DNS fail over. Thus your DB connection pool should be configured to ‘test on borrow’, ‘discard on exception’, relatively short TTL etc to facilitate failover.
Failover may not be completely transparent to the engine with regard to process level transactions, hence ideally design idempotency and granular checkpoints into your processes and services. Note that even in the case of a single DB node, the same is true, the DB can fail mid process transactions.
I have successfully used RDS Multi-AZ MySQL in load tests without issue…
regards
Rob
Hi Rob thanks for the clarification and the details you provided - OK sure Multi-AZ would be great, and aurora serverless support would be even better…
I thought that Multi-AZ might not be supported due to the restrictions noted in the database-clustering-replication documentation, but if you had some load tests running without issues I hope the camunda team will get into this as well.
Cheers,
Michael
I’m also interested in this topic. Considering a new, potentially large installation of Camunda and would really prefer to use Aurora (including support for its failover modes).
Paul