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 andrei...@gmail.com 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 matt...@gmail.com 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 h2-database+unsubscr...@googlegroups.com. To view this discussion on the web visit https://groups.google.com/d/msgid/h2-database/20a6f4fb-b624-4698-a01a-70cddda6337bn%40googlegroups.com.
