Thanks for the tip, Mike. After changing the three calls IndexWriter.commit();
<revert merge policy to allow merging to happen> IndexWriter.maybeMerge(); IndexWriter.waitForMerges(); to simply calling IndexWriter.close(true) the disk size and run time are now very close to the case of parallel segment merges. On Sat, Jun 2, 2012 at 6:43 AM, Michael McCandless < luc...@mikemccandless.com> wrote: > On Fri, Jun 1, 2012 at 8:09 PM, Vitaly Funstein <vfunst...@gmail.com> > wrote: > > Yes, I am only calling IndexWriter.addDocument() > > OK. > > > Interestingly, relative performance of either approach seems to greatly > > depend on the number of documents per index. In both types of runs, I > used > > 10 writer threads, each writing documents with the same set of fields > (but > > random values), into its own index as fast as possible, on a 16 core box, > > using a rotational disk for index storage (results from my original post > > were obtained from a Fusion IO drive, and an even higher # of cores per > > machine). > > Mmmmm Fusion IO drive :) > > > For smaller index sizes, the choice of whether to merge segments > > in parallel makes much less of a difference, if at all. > > > > So the matrix looks like this: > > > > # docs/index concurrent merges? total time, sec total disk > size > > > =========================================================================== > > 200K Y 56.8 1.5 G > > 200K N 59.6 2.6 G > > 1M Y 304 7.4 G > > 1M N 493 14 G > > > > As you can see, the total size on disk is always much larger when merging > > at the end; here are directory listings, for each case: > > OK so for a biggish index merging concurrently is faster; this is what > I'd expect. > > > Concurrent merging: > > > > total 150M > > -rw-r--r-- 1 bench perf 0 2012-06-01 16:33 write.lock > > -rw-r--r-- 1 bench perf 87 2012-06-01 16:33 _a.fnm > > -rw-r--r-- 1 bench perf 17M 2012-06-01 16:33 _a.tis > > -rw-r--r-- 1 bench perf 186K 2012-06-01 16:33 _a.tii > > -rw-r--r-- 1 bench perf 105K 2012-06-01 16:33 _a.prx > > -rw-r--r-- 1 bench perf 4.8M 2012-06-01 16:33 _a.frq > > -rw-r--r-- 1 bench perf 87 2012-06-01 16:33 _l.fnm > > -rw-r--r-- 1 bench perf 17M 2012-06-01 16:33 _l.tis > > -rw-r--r-- 1 bench perf 186K 2012-06-01 16:33 _l.tii > > -rw-r--r-- 1 bench perf 105K 2012-06-01 16:33 _l.prx > > -rw-r--r-- 1 bench perf 4.8M 2012-06-01 16:33 _l.frq > > -rw-r--r-- 1 bench perf 87 2012-06-01 16:33 _w.fnm > > -rw-r--r-- 1 bench perf 17M 2012-06-01 16:33 _w.tis > > -rw-r--r-- 1 bench perf 186K 2012-06-01 16:33 _w.tii > > -rw-r--r-- 1 bench perf 105K 2012-06-01 16:33 _w.prx > > -rw-r--r-- 1 bench perf 4.8M 2012-06-01 16:33 _w.frq > > -rw-r--r-- 1 bench perf 87 2012-06-01 16:33 _17.fnm > > -rw-r--r-- 1 bench perf 17M 2012-06-01 16:33 _17.tis > > -rw-r--r-- 1 bench perf 186K 2012-06-01 16:33 _17.tii > > -rw-r--r-- 1 bench perf 105K 2012-06-01 16:33 _17.prx > > -rw-r--r-- 1 bench perf 4.8M 2012-06-01 16:33 _17.frq > > -rw-r--r-- 1 bench perf 2.3M 2012-06-01 16:33 _1j.cfs > > -rw-r--r-- 1 bench perf 87 2012-06-01 16:33 _1i.fnm > > -rw-r--r-- 1 bench perf 2.3M 2012-06-01 16:33 _1k.cfs > > -rw-r--r-- 1 bench perf 2.3M 2012-06-01 16:33 _1m.cfs > > -rw-r--r-- 1 bench perf 2.3M 2012-06-01 16:33 _1l.cfs > > -rw-r--r-- 1 bench perf 2.3M 2012-06-01 16:33 _1n.cfs > > -rw-r--r-- 1 bench perf 17M 2012-06-01 16:33 _1i.tis > > -rw-r--r-- 1 bench perf 186K 2012-06-01 16:33 _1i.tii > > -rw-r--r-- 1 bench perf 105K 2012-06-01 16:33 _1i.prx > > -rw-r--r-- 1 bench perf 4.8M 2012-06-01 16:33 _1i.frq > > -rw-r--r-- 1 bench perf 148K 2012-06-01 16:33 _1p.cfs > > -rw-r--r-- 1 bench perf 2.3M 2012-06-01 16:33 _1o.cfs > > -rw-r--r-- 1 bench perf 28M 2012-06-01 16:33 _0.cfx > > -rw-r--r-- 1 bench perf 2.8K 2012-06-01 16:33 segments_2 > > -rw-r--r-- 1 bench perf 20 2012-06-01 16:33 segments.gen > > > > Deferred merging: > > > > total 261M > > -rw-r--r-- 1 bench perf 0 2012-06-01 16:41 write.lock > > -rw-r--r-- 1 bench perf 2.3M 2012-06-01 16:41 _0.cfs > > -rw-r--r-- 1 bench perf 2.3M 2012-06-01 16:41 _1.cfs > > -rw-r--r-- 1 bench perf 2.3M 2012-06-01 16:41 _3.cfs > > -rw-r--r-- 1 bench perf 2.3M 2012-06-01 16:41 _2.cfs > > -rw-r--r-- 1 bench perf 2.3M 2012-06-01 16:41 _4.cfs > > -rw-r--r-- 1 bench perf 2.3M 2012-06-01 16:41 _6.cfs > > -rw-r--r-- 1 bench perf 2.3M 2012-06-01 16:41 _5.cfs > > -rw-r--r-- 1 bench perf 2.3M 2012-06-01 16:41 _7.cfs > > -rw-r--r-- 1 bench perf 2.3M 2012-06-01 16:41 _9.cfs > > -rw-r--r-- 1 bench perf 2.3M 2012-06-01 16:41 _8.cfs > > -rw-r--r-- 1 bench perf 2.3M 2012-06-01 16:41 _a.cfs > > -rw-r--r-- 1 bench perf 2.3M 2012-06-01 16:41 _c.cfs > > -rw-r--r-- 1 bench perf 2.3M 2012-06-01 16:41 _b.cfs > > -rw-r--r-- 1 bench perf 2.3M 2012-06-01 16:41 _d.cfs > > -rw-r--r-- 1 bench perf 2.3M 2012-06-01 16:41 _f.cfs > > -rw-r--r-- 1 bench perf 2.3M 2012-06-01 16:41 _e.cfs > > -rw-r--r-- 1 bench perf 2.3M 2012-06-01 16:41 _g.cfs > > -rw-r--r-- 1 bench perf 2.3M 2012-06-01 16:41 _i.cfs > > -rw-r--r-- 1 bench perf 2.3M 2012-06-01 16:41 _h.cfs > > -rw-r--r-- 1 bench perf 2.3M 2012-06-01 16:41 _j.cfs > > -rw-r--r-- 1 bench perf 2.3M 2012-06-01 16:41 _l.cfs > > -rw-r--r-- 1 bench perf 2.3M 2012-06-01 16:41 _k.cfs > > -rw-r--r-- 1 bench perf 2.3M 2012-06-01 16:41 _m.cfs > > -rw-r--r-- 1 bench perf 2.3M 2012-06-01 16:41 _n.cfs > > -rw-r--r-- 1 bench perf 2.3M 2012-06-01 16:41 _p.cfs > > -rw-r--r-- 1 bench perf 2.3M 2012-06-01 16:41 _o.cfs > > -rw-r--r-- 1 bench perf 2.3M 2012-06-01 16:41 _q.cfs > > -rw-r--r-- 1 bench perf 2.3M 2012-06-01 16:41 _s.cfs > > -rw-r--r-- 1 bench perf 2.3M 2012-06-01 16:41 _r.cfs > > -rw-r--r-- 1 bench perf 2.3M 2012-06-01 16:41 _t.cfs > > -rw-r--r-- 1 bench perf 2.3M 2012-06-01 16:41 _v.cfs > > -rw-r--r-- 1 bench perf 2.3M 2012-06-01 16:41 _u.cfs > > -rw-r--r-- 1 bench perf 2.3M 2012-06-01 16:41 _w.cfs > > -rw-r--r-- 1 bench perf 2.3M 2012-06-01 16:41 _x.cfs > > -rw-r--r-- 1 bench perf 2.3M 2012-06-01 16:41 _z.cfs > > -rw-r--r-- 1 bench perf 2.3M 2012-06-01 16:41 _y.cfs > > -rw-r--r-- 1 bench perf 2.3M 2012-06-01 16:41 _11.cfs > > -rw-r--r-- 1 bench perf 2.3M 2012-06-01 16:41 _10.cfs > > -rw-r--r-- 1 bench perf 2.3M 2012-06-01 16:41 _13.cfs > > -rw-r--r-- 1 bench perf 2.3M 2012-06-01 16:41 _12.cfs > > -rw-r--r-- 1 bench perf 2.3M 2012-06-01 16:41 _16.cfs > > -rw-r--r-- 1 bench perf 2.3M 2012-06-01 16:41 _15.cfs > > -rw-r--r-- 1 bench perf 2.3M 2012-06-01 16:41 _14.cfs > > -rw-r--r-- 1 bench perf 2.3M 2012-06-01 16:41 _18.cfs > > -rw-r--r-- 1 bench perf 2.3M 2012-06-01 16:41 _17.cfs > > -rw-r--r-- 1 bench perf 2.3M 2012-06-01 16:41 _1b.cfs > > -rw-r--r-- 1 bench perf 2.3M 2012-06-01 16:41 _1a.cfs > > -rw-r--r-- 1 bench perf 2.3M 2012-06-01 16:41 _19.cfs > > -rw-r--r-- 1 bench perf 2.3M 2012-06-01 16:41 _1d.cfs > > -rw-r--r-- 1 bench perf 2.3M 2012-06-01 16:41 _1c.cfs > > -rw-r--r-- 1 bench perf 2.3M 2012-06-01 16:41 _1g.cfs > > -rw-r--r-- 1 bench perf 2.3M 2012-06-01 16:41 _1f.cfs > > -rw-r--r-- 1 bench perf 2.3M 2012-06-01 16:41 _1e.cfs > > -rw-r--r-- 1 bench perf 2.3M 2012-06-01 16:41 _1j.cfs > > -rw-r--r-- 1 bench perf 2.3M 2012-06-01 16:41 _1i.cfs > > -rw-r--r-- 1 bench perf 2.3M 2012-06-01 16:41 _1h.cfs > > -rw-r--r-- 1 bench perf 28M 2012-06-01 16:41 _0.cfx > > -rw-r--r-- 1 bench perf 137K 2012-06-01 16:42 _1k.cfs > > -rw-r--r-- 1 bench perf 12K 2012-06-01 16:42 segments_2 > > -rw-r--r-- 1 bench perf 20 2012-06-01 16:42 segments.gen > > -rw-r--r-- 1 bench perf 87 2012-06-01 16:42 _1l.fnm > > -rw-r--r-- 1 bench perf 87 2012-06-01 16:42 _1n.fnm > > -rw-r--r-- 1 bench perf 17M 2012-06-01 16:42 _1l.tis > > -rw-r--r-- 1 bench perf 186K 2012-06-01 16:42 _1l.tii > > -rw-r--r-- 1 bench perf 105K 2012-06-01 16:42 _1l.prx > > -rw-r--r-- 1 bench perf 4.8M 2012-06-01 16:42 _1l.frq > > -rw-r--r-- 1 bench perf 87 2012-06-01 16:42 _1o.fnm > > -rw-r--r-- 1 bench perf 17M 2012-06-01 16:42 _1n.tis > > -rw-r--r-- 1 bench perf 186K 2012-06-01 16:42 _1n.tii > > -rw-r--r-- 1 bench perf 105K 2012-06-01 16:42 _1n.prx > > -rw-r--r-- 1 bench perf 4.8M 2012-06-01 16:42 _1n.frq > > -rw-r--r-- 1 bench perf 87 2012-06-01 16:42 _1p.fnm > > -rw-r--r-- 1 bench perf 17M 2012-06-01 16:42 _1o.tis > > -rw-r--r-- 1 bench perf 186K 2012-06-01 16:42 _1o.tii > > -rw-r--r-- 1 bench perf 105K 2012-06-01 16:42 _1o.prx > > -rw-r--r-- 1 bench perf 4.8M 2012-06-01 16:42 _1o.frq > > -rw-r--r-- 1 bench perf 17M 2012-06-01 16:42 _1p.tis > > -rw-r--r-- 1 bench perf 186K 2012-06-01 16:42 _1p.tii > > -rw-r--r-- 1 bench perf 105K 2012-06-01 16:42 _1p.prx > > -rw-r--r-- 1 bench perf 4.8M 2012-06-01 16:42 _1p.frq > > -rw-r--r-- 1 bench perf 87 2012-06-01 16:42 _1m.fnm > > -rw-r--r-- 1 bench perf 17M 2012-06-01 16:42 _1m.tis > > -rw-r--r-- 1 bench perf 186K 2012-06-01 16:42 _1m.tii > > -rw-r--r-- 1 bench perf 105K 2012-06-01 16:42 _1m.prx > > -rw-r--r-- 1 bench perf 4.8M 2012-06-01 16:42 _1m.frq > > Hmm: you should close the writer (or do a final commit) before testing > the size of the index. I suspect in the 2nd case because no final > commit happened, the original segments are still around. > > Mike > > --------------------------------------------------------------------- > To unsubscribe, e-mail: java-user-unsubscr...@lucene.apache.org > For additional commands, e-mail: java-user-h...@lucene.apache.org > >
