Hi,
we've got very big indexes/workspaces on our production servers which have from
3,000,000 to 8,000,000 nodes and are still growing because of creation of
versions and adding new nodes.
When it happens that the VM in which Jackrabbit lives in crashes during a write
operation, Jackrabbit nicely applies the redo log on a restart which gets done
quite quick but then starts its consistency check. This check takes from 30
minutes to 2 hours depending on the repository. In this time our application is
offline which we would of course like to avoid ;) Our system uses a bundle
oracle pm which probably doesn't make things better.
I had a quick glance at the consistency check code and it seems like there is
nothing that could be substantially optimized in that place. I thought it might
be possible to just include those index segments that where used while replaying
the redo log but as the consistency check works this is impossible.
I think the only way to fasten startup is to avoid the occurrence of the errors
that the check is checking for at all. Since the redo log mechanism seems quite
good I'm not sure if those errors (MissingAncestor, MultipleEntries,
NodeDeleted, UnknownParent) can still occur. Could you maybe elaborate on the
situations where you expect those errors to arise?
For now I'm thinking about disabling consistency checks at all by default and
run them in a maintenance window at night. Unfortunately this might be a bit
dangerous if parts of the application rely on certain nodes to be found by
queries :/
WDYT?
Cheers,
Christoph
- Consistency check of indexes takes to long Christoph Kiehl
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