Interesting suggestion. However, this would perhaps have the same effect (deleting/compacting the old DB is what makes the system slower)...?
On Thu, Jun 14, 2012 at 2:54 PM, Robert Newson <[email protected]> wrote: > Do you eventually delete every document you add? > > If so, consider using a rolling database scheme instead. At some > point, perhaps daily, start a new database and write new transaction > logs there. Continue deleting old logs from the previous database(s) > until they're empty (doc_count:0) and then delete the database. > > B. > > On 14 June 2012 13:44, Nicolas Peeters <[email protected]> wrote: > > I'd like some advice from the community regarding compaction. > > > > *Scenario:* > > > > We have a large-ish CouchDB database that is being used for transactional > > logs (very write heavy). Once in a while, we delete some of the records > in > > large batches and we have scheduled compaction (not automatic (yet)) > every > > 12hours. > > > > From what I can see, the DB is being hammered significantly every 12 > hours > > and the compaction is taking 4 hours (with a size of 50-100GB of log > data). > > > > *The problem:* > > > > The problem is that compaction takes a very long time and reduces the > > performance of the stack. It seems that it's hard for the compaction > > process to "keep up" with the insertions, hence why it takes so long. > Also, > > what I'm not sure is how "incremental" the compaction is... > > > > 1. In this case, would it make sense to run the compaction more often > > (every 10 minutes); since we're write-heavy. > > 1. Should we just run more often? (so hopefully it doesn't do > > unnecessary work too often). Actually, in our case, we should > probably > > never have automatic compaction if there has been no "termination". > > 2. Or actually only once in a while? (bigger batch, but less > > "useless" overhead) > > 3. Or should we just wait that a given size (which is the problem > > really) is hit and use the auto compaction (in CouchDB 1.2.0) for > this? > > 2. In CouchDB 1.2.0 there's a new feature: auto > > compaction< > http://wiki.apache.org/couchdb/Compaction#Automatic_Compaction> > > which > > may be useful for us. There's the "strict_window" feature to give a max > > amount of time to compact and cancel the compaction after that (in > order > > not to have it running for 4h+…). I'm wondering what the impact of > that is > > on the long run. What if the compaction cannot be completed in that > window? > > > > Thanks a lot! > > > > Nicolas >
