https://bugs.openldap.org/show_bug.cgi?id=8958

--- Comment #27 from Ondřej Kuzník ondra@mistotebe.net --- On Tue, Aug 03, 2021 at 12:42:01PM +0000, openldap-its@openldap.org wrote:

I don't think we should be changing anything else about how tpool handles pauses. We should just be fixing this specific case of the indexer being a slow task, by implementing checkpointing into the indexer. I.e., when it detects a pause request it should save its current progress and pause itself. If it gets resumed it can pick up where it left off, or if a config change affects it it can abort or or start over. A checkpointing mechanism is needed anyway, for the case of a (clean) shutdown while the indexer is running.

I'll put a suggestion here that we discussed previously: to support this checkpointing for pauses/shutdowns, the indexer could be writing to a "scratch" database (whatever that means for each backend) along with resume data and move them into place when finished. You mentioned that for liblmdb, this would need support for a database to be renamed.