I updated the SolrCloud page here: http://wiki.apache.org/solr/SolrCloud to include how to change this option.
Baaaah, "Soft commits flush to the op system" should have read "Hard commits flush the transaction log to the op system". Blame it on just getting back from the dentist, that was just completely wrong. Best, Erick On Tue, Aug 27, 2013 at 12:08 PM, Mark Miller <markrmil...@gmail.com> wrote: > On Aug 27, 2013, at 11:54 AM, Erick Erickson <erickerick...@gmail.com> > wrote: > > > Soft commits flush to the op system, so > > a JVM crash/termination shouldn't affect it anyway. > > A soft commit is not a hard commit, so there are not guarantees like this. > It searches committed and non committed segments - non committed segments > will not magically be committed after a JVM crash. > > > Turning on the fsync > > would just be a little bit of extra protection…. > > If you don't have replication, it turns on strong 'durability' promises. > Without it, you are on your own if you have a hard machine reset. If > durability is important to you and you don't have replication, it's > important to use the fync option here. Unless you have a great, long time, > battery backup and/or an env such that hard resets don't concern you for > some reason. It comes down to your requirments. > > Responses to Sandro inline below: > > On Aug 27, 2013, at 11:43 AM, Sandro Zbinden <zbin...@imagic.ch> wrote: > > > Hey Mark > > > > Thank you very much for the quick answer. We have a single node > environment. > > > > I try to find the fsync option but was not successful. Ended up in the > UpdateLog class :-) > > > > How do I enable fsync in the solrconfig.xml ? > > In the updateLog config, its a syncLevel=fsync param. > > > > > > > Besides that: > > > > If solr soft commit feature has a on disk guarantee with a transaction > log why we don't use solr soft commit as the default commit option ? > > Yes, for visibility you should use soft commit. You should also have an > auto hard commit with openSearcher=false - it's just about flushing the > transaction log and freeing memory in this configuraiton - which is why it > makes sense to simply turn on the auto commit for regular hard commits. You > may or may not want to use auto soft commits. > > - Mark > > > > > > > -----Ursprüngliche Nachricht----- > > Von: Mark Miller [mailto:markrmil...@gmail.com] > > Gesendet: Dienstag, 27. August 2013 17:12 > > An: solr-user@lucene.apache.org > > Betreff: Re: Transaction log "on-disk" guarantees > > > > > > On Aug 27, 2013, at 11:08 AM, Sandro Zbinden <zbin...@imagic.ch> wrote: > > > >> Can we activate the transaction log to have on disk guarantees and then > use the solr soft commit feature ? > > > > Yes you can. If you only have a single node (no replication), you > probably want to turn on fsync via the config. > > > > - Mark > > > >
