JPA - Performance with using multiple entity manager
- by Nguyen Tuan Linh
My situation is:
The code is not mine
I have two kinds of database: one is Dad, one is Son.
In Dad, I have a table to store JNDI name. I will look up Dad using JNDI, create entity manager, and retrieve this table.
From these retrieved JNDI names, I will create multiple entity managers using multiple Son databases.
The problem is:
Son have thousands of entities. It takes each Son database around 10 minutes to load all entities. If there is 4 Son databases, it will be 40 minutes.
My question:
Is there any way to load all entities and use them for all entity manager?
Please look at the code below
For each Son JNDI:
Map<String, String> puSonProperties = new HashMap<String, String>();
puSonProperties.put("javax.persistence.jtaDataSource", sonJndi);
EntityManagerFactory emf = Persistence.createEntityManagerFactory("PUSon", puSonProperties);
PUSon - All of them use the same persistence unit
log.info("Verify entity manager for son: {0} - {1}", sonCode,
emSon.find(Son_configuration.class, 0) != null ? "ok" : "failed!");
This is the actual code where the loading of all entities begins. 10 mins.
