Wow.. thanks for the great answers Erick! This answered my concerns perfectly.
Mike On Thu, Sep 1, 2011 at 7:54 AM, Erick Erickson <erickerick...@gmail.com>wrote: > See below: > > On Wed, Aug 31, 2011 at 2:16 PM, Mike Austin <mike.aus...@juggle.com> > wrote: > > I've set up a master slave configuration and it's working great! I know > > this is the better setup but if I had just one index due to requirements, > > I'd like to know more about the performance hit of the commit. let's just > > assume I have a decent size index of a few gig normal sized documents > with > > high traffic. A few questions: > > > > - (main question) When you do a commit on a single index, is there > anytime > > when the reads will not have an index to search on? > No. While the new searcher is warming up, all incoming searches are > handled by the old searcher. When the new searcher is warmed up, > new requests are routed to it, and when the last search is completed > in the old searcher, it's shut down > > > - With the rebuilding of caches and whatever else happens, is the only > > downside the fact that the server performance will be degraded due to > file > > copy, cache warming, etc.. or will the index be actually locked at some > > point? > The index will not be locked, if by locked you mean the searches will > not happen. See above. The server will certainly have more work to > do, and if you're running close to the limits you might notice some > slowdown. But often there is no noticeable pause. Note that while > all this goes on, you will have *two* copies of the caches etc. in > memory... > > > - On a commit, do the files get copied so you need double the space or is > > that just the optimize? > You have to allow for the relatively rare instance when the merge > process combines all your segments into one, which will require > at least double the disk space. Optimize guarantees this > will happen, but it can (and will) happen on commit occasionally. > > > > > I know a master/slave setup is used to reduce these issues, but if I had > > only one server I need to know the potential risks. > Well, you're just putting lots of stuff on a server. Solr will quite > happily deal > with this situation and, depending upon how much traffic you have and > your machine's size, this may be fine. Do be aware of the "warmup hell" > problem and don't commit too frequently or your warming searchers > may tie their knickers in a knot. > > And one risk in this setup is that you have no way to quickly bring up > a server if your one machine crashes, you have to re-index *all* your data. > > Best > Erick > > > > > Thanks, > > Mike > > >
