Hello guys,
I would need your help in understanding the code in the
CachingHierarchyManager.stateDiscarded() method (Jackrabbit 2.2.4).
A short background:
I am working on a tool to purge orphaned version history from the
repository (version history for nodes, which are no longer present in
the repository).
The version store is quite large (the row count in the version bundle
table is around 12 000 000 entries).
When profiling the tool execution I see in the snapshot that in the
CachingHierarchyManager.stateDiscarded() method the
provider.hasItemState(discarded.getId()) is called.
In my case this happens quite often and the call provider.hasItemState()
goes into the DB and loads the bundle.
The things is that the item is no longer present and the
provider.hasItemState() evaluates to false.
The call in my case is coming from the
org.apache.jackrabbit.core.state.ChangeLog.persisted() where we have the
following lines:
...
for (ItemState state : deletedStates()) {
state.setStatus(ItemState.STATUS_EXISTING_REMOVED);
state.notifyStateDestroyed();
state.discard();
}
...
The state.discard() calls the notifyStateDiscarded();
Is it really needed here after we have already called
state.notifyStateDestroyed()?
If yes, is there any way we can optimize the check in the
CachingHierarchyManager.stateDiscarded() to not call
provider.hasItemState() in some cases? Perhaps check for
discarded.getStatus() != ItemState.STATUS_EXISTING_REMOVED first or similar?
I am attaching the profiler snapshot
(CachingHierarchyManager-stateDiscarded.png) and just in case the image
won't get through the mailing list, here is a text representation of the
method call trace:
org.apache.jackrabbit.core.state.ChangeLog.persisted()
- org.apache.jackrabbit.core.state.ItemState.discard()
- org.apache.jackrabbit.core.state.ItemState.notifyStateDiscarded()
-
org.apache.jackrabbit.core.state.SharedItemStateManager.stateDiscarded(ItemState)
-
org.apache.jackrabbit.core.state.StateChangeDispatcher.notifyStateDiscarded(ItemState)
-
org.apache.jackrabbit.core.state.SharedItemStateManager.stateDiscarded(ItemState)
-
org.apache.jackrabbit.core.state.StateChangeDispatcher.notifyStateDiscarded(ItemState)
-
org.apache.jackrabbit.core.CachingHierarchyManager.stateDiscarded(ItemState)
-
org.apache.jackrabbit.core.state.SharedItemStateManager.hasItemState(ItemId)
-
org.apache.jackrabbit.core.state.SharedItemStateManager.hasNonVirtualItemState(ItemId)
-
org.apache.jackrabbit.core.persistence.bundle.AbstractBundlePersistenceManager.exists(PropertyId)
-
org.apache.jackrabbit.core.persistence.bundle.AbstractBundlePersistenceManager.getBundle(NodeId)
-
org.apache.jackrabbit.core.persistence.pool.BundleDbPersistenceManager.loadBundle(NodeId)
-
org.apache.jackrabbit.core.util.db.ConnectionHelper.exec(String,
Object[], boolean, int)
Thank you in advance for any hints!
Sergiy Shyrkov
