[hibernate-dev] Design: HSEARCH-1032 MassIndexer with a live update mechanism

[Hardy Ferentschik]

I also favour option B

On 12 Jan 2013, at 2:42 PM, Sanne Grinovero <sanne at hibernate.org> wrote:

> ## SPI changes
> With this design we need to be able to:
> - dynamically instantiate a second Directory in a different path
> - switch to delegate writes to both directories / one directory
> - control from where Readers are opened
> - make sure closed Readers go back to the original pool where they
> come from as their reference source could have been changed
> - be able to switch (permanently) to a different active index
> - destroy old index
> 
> I'm afraid each of these can affect our SPIs; likely at least
> IndexManager.

Most of the items seem to be implementation details, but I don't see a major issues
in making some SPI changes provide they are introduced properly.

> I guess we could agree that if the user configured an index to be in -
> say - "/var/lucene/persons" we could store the indexes in
> "/var/lucene/persons/index-a" and "/var/lucene/persons/index-b",

> alternating in similar way to the FSMasterDirectoryProvider, but that
> takes away some control on index position and is not backwards
> compatible. Would this be acceptable?

Yes

> # Timeline
> This might need to be moved to 5.0 because of the various backwards
> compatibility concerns - ideally if some community user feels to
> participate we could share some early code in experimental branches
> and work together.

Search 5 would be my guess as well.

--Hardy