IBM WebSphere eXtreme Scale 6

Write-through and write-behind

Getting back to the slow down due to the Loader configuration, by default, the Loader uses write-through behavior:

Now we know the problem. Write-through behavior wraps a database transaction for every write! For every ObjectGrid transaction, we execute one database transaction. On the up side, every object assuredly reaches the database, provided it doesn't violate any relational constraints. Despite this harsh reaction to write-through behavior, it is essential for objects that absolutely must get to the database as fast as possible. The problem is that we hit the database for every write operation on every BackingMap. ...