Hello Andrei, thanks very much for your reply.
Yes, I'm aware I'm on an old version: if it's not broken, don't fix it ;) Version 1.4.197 has been rock-solid for us for years, and I'm always loathe to change things for no reason. But you have given me a good reason, so I'll give the latest MVStore a try. Can you recommend the best way to 'manually' compact the database in the latest release? And just to be sure: could there be any data-loss issues from flushing the cache? Cheers, Matt. On Friday, July 16, 2021 at 4:45:12 AM UTC+9:30 [email protected] wrote: > Hi Matt, > > If you are experiencing a problem, which looks and smells like a > cuncurrency issue, then there is definitely a good reason to suspect a > concurrency issue. 8-) > The real question here is: if you care enough about those problems, why > are you still on version 1.4.197. MVStore's concurrency / synchronization > was totally re-designed since then (and we are talking years here), for > example you will not even find MVStore.compactRewriteFully() method > anymore, but instead it might just do all that space management, so you > won't need that background operation at all. > In any case, I would not expect that someone will look at 1.4.197 issues > at this point. On the other hand, if you will find similar problem with > current trunk version, and will be able to reproduce it, I will be more > than happy to work on it. > > Cheers, > Andrei. > > On Thursday, July 15, 2021 at 3:39:40 AM UTC-4 [email protected] wrote: > >> Hello, >> >> I'm trying to track down a perplexing problem when using an MVStore, >> where it appears that a write using MVMap.put() is being dropped (H2 >> 1.4.197). It's only happened twice, but both of those times have been after >> a series of cache flushes, and where the .put() is done *concurrently* with >> a long-running call to compactRewriteFully() (which takes around 90s for >> this DB). We're not using rollback, or transactions or anything fancy, just >> raw put(), get(), commit(). >> >> My question: is there any reason to suspect that the cache flushes or, I >> think more likely, the concurrent compactRewriteFully() might somehow be >> causing the write to be dropped? >> >> If so, I'm open to compacting the DB in some other way, but >> compactRewriteFully() has been the most reliable at keeping the DB size >> stable, despite its overhead (it's currently being run from a background >> thread that runs once a day in the wee hours). >> >> Cheers, >> >> Matt. >> > -- You received this message because you are subscribed to the Google Groups "H2 Database" group. To unsubscribe from this group and stop receiving emails from it, send an email to [email protected]. To view this discussion on the web visit https://groups.google.com/d/msgid/h2-database/20a6f4fb-b624-4698-a01a-70cddda6337bn%40googlegroups.com.
