[9fans] replica question

[Rudolf Sykora <rudolf.sykora@gmail.com>]

Hello,

Yesterday I read replica(8), played with it a bit, and I have the
following question:

Say I have a directory A which I—from time to time—want to replicate
to directory B. With replica/updatedb I maintain two files, A.db and
A.log, describing the situation in the A directory.

If A.log has existed since the time replica/updatedb was run for the
first time, I may use this log as an input to replica/applylog and
create a replica of A in B.

However, I don't understand what one should do if this log was removed
or somehow shortened (so that it does not mention the files' addition
anymore).  Some such shortening is, I believe, reasonable, since after
say 10 years nobody is probably interested in all the files' changes.
But, if I understand, it is exclusively the log itself (i.e., not the
server database file A.db) that is used for synchronization by
replica...

Is there any more thorough explanation somewhere describing how replica works?

Thank you for hints/explanation!

Ruda