Hi Jan, thanks for your prompt reply. I'll try to stop the writes today.
Best, Alan. On Mon, Jul 6, 2020 at 10:42 AM Jan Lehnardt <[email protected]> wrote: > > On 6. Jul 2020, at 10:26, Alan Malta <[email protected]> wrote: > > > > Dear experts, > > > > apologies if I'm asking something that has already been asked here, if > > so, I'm happy to have just a link to a previous discussion. > > > > Coming to the problem, over the last week, one of my couch instances > > went twice from ?~20GB to ~300GB. The problem is that the compaction > > never manages to switch the databases because there are always a few > > thousand changes to catch up on (~30k), e.g.: > > """ > > Compaction file still behind main file (update seq=199559009. compact > > update seq=199532061). Retrying. > > """ > > > > By the time it catches up, there is again another 20k or 30k changes to > > process. > > > > I have this setup for many years now (CentOS7, CouchDB 1.6.1, probably > > a normal load), so I wonder if this is actually a symptom that > > something else is not fine in the system? Besides stopping database > > writes, is there anything else that I could do to avoid it? > > Stopping database writes is the way to do this in 1.x (which we’ve long > stopped supporting). If you have the option to increase IOPS on your > system, that might also help. > > I’d say this is normal and you have reached database sizes where the > existing underlying hardware doesn’t suffice to support normal operation. > > It doesn’t look like something else is not fine. > > > > > Thank you in advance. > > Alan. > > > > PS.: Out of curiosity, is it handled in a different/better way in the > > latest CouchDB versions (like 3.1)? > > From 2.x onwards, databases can be sharded, that is split up into multiple > database files (which individually are the same as a single database from > 1.x). So for example with four shards, each shard will only receive 1/4th > the write load, making it easier to catch up with. > > Best > Jan > — > Professional Support for Apache CouchDB: > https://neighbourhood.ie/couchdb-support/ > >
