Program guide > Access data with client applications
Program for transactions
Applications that require transactions introduce such considerations as handling locks, handling collisions, and transaction isolation.
- Transaction processing overview
WebSphere eXtreme Scale uses transactions as its mechanism for interaction with data.
- Use locking
Locks have life cycles and different types of locks are compatible with others in various ways. Locks must be handled in the correct order to avoid deadlock scenarios.
- Transaction isolation
For transactions, you can configure each backing map configuration with one of three lock strategies: pessimistic, optimistic or none. When you are using pessimistic and optimistic locking, eXtreme Scale uses shared (S), upgradeable (U) and exclusive (X) locks to maintain consistency. This locking behavior is most notable when using pessimistic locking, because optimistic locks are not held. Use one of three transaction isolation levels to tune the locking semantics that eXtreme Scale uses to maintain consistency in each cache map: repeatable read, read committed and read uncommitted.
- Optimistic collision exception
You can receive an OptimisticCollisionException directly, or receive it with an ObjectGridException.
- Run parallel business logic on the data grid (DataGrid API)
The DataGrid API provides a simple programming interface to run business logic over all or a subset of the data grid in parallel with where the data is located.
Parent topic:Access data with client applications
Interacting with an ObjectGrid using ObjectGridManager
Data access with indexes (Index API)
Access data in WebSphere eXtreme Scale
Use Sessions to access data in the grid
Cache objects with no relationships involved (ObjectMap API)
Cache objects and their relationships (EntityManager API)
Retrive entities and objects (Query API)
Configure clients with WebSphere eXtreme Scale
Configure a locking strategy
Connect to a distributed ObjectGrid