prometheus/index
Brian Brazil 89a90fe96c
Simplify mergedPostings.Seek (#595)
The current implementation leads to very slow behaviour when there's
many lists, this no worse than n log k, where k is the number of posting
lists.

Adjust benchmark to catch this.

Remove flattening of without lists, not needed anymore.

Benchmark versus 0.4.0 (used in Prometheus 2.7):
```
benchmark                                                            old ns/op      new ns/op      delta
BenchmarkHeadPostingForMatchers/n="1"-8                              189907976      188863880      -0.55%
BenchmarkHeadPostingForMatchers/n="1",j="foo"-8                      113950106      110791414      -2.77%
BenchmarkHeadPostingForMatchers/j="foo",n="1"-8                      104965646      102388760      -2.45%
BenchmarkHeadPostingForMatchers/n="1",j!="foo"-8                     138743592      104424250      -24.74%
BenchmarkHeadPostingForMatchers/i=~".*"-8                            5279594954     5206096267     -1.39%
BenchmarkHeadPostingForMatchers/i=~".+"-8                            8004610589     6184527719     -22.74%
BenchmarkHeadPostingForMatchers/i=~""-8                              2476042646     1003920432     -59.45%
BenchmarkHeadPostingForMatchers/i!=""-8                              7178244655     6059725323     -15.58%
BenchmarkHeadPostingForMatchers/n="1",i=~".*",j="foo"-8              199342649      166642946      -16.40%
BenchmarkHeadPostingForMatchers/n="1",i=~".*",i!="2",j="foo"-8       215774683      167515095      -22.37%
BenchmarkHeadPostingForMatchers/n="1",i!=""-8                        2214714769     392943663      -82.26%
BenchmarkHeadPostingForMatchers/n="1",i!="",j="foo"-8                2148727410     322289262      -85.00%
BenchmarkHeadPostingForMatchers/n="1",i=~".+",j="foo"-8              2170658009     338458171      -84.41%
BenchmarkHeadPostingForMatchers/n="1",i=~"1.+",j="foo"-8             235720135      70597905       -70.05%
BenchmarkHeadPostingForMatchers/n="1",i=~".+",i!="2",j="foo"-8       2190570590     343034307      -84.34%
BenchmarkHeadPostingForMatchers/n="1",i=~".+",i!~"2.*",j="foo"-8     2373784439     387297908      -83.68%

benchmark                                                            old allocs     new allocs     delta
BenchmarkHeadPostingForMatchers/n="1"-8                              33             33             +0.00%
BenchmarkHeadPostingForMatchers/n="1",j="foo"-8                      33             33             +0.00%
BenchmarkHeadPostingForMatchers/j="foo",n="1"-8                      33             33             +0.00%
BenchmarkHeadPostingForMatchers/n="1",j!="foo"-8                     41             39             -4.88%
BenchmarkHeadPostingForMatchers/i=~".*"-8                            56             56             +0.00%
BenchmarkHeadPostingForMatchers/i=~".+"-8                            251577         100115         -60.21%
BenchmarkHeadPostingForMatchers/i=~""-8                              251123         100077         -60.15%
BenchmarkHeadPostingForMatchers/i!=""-8                              251525         100112         -60.20%
BenchmarkHeadPostingForMatchers/n="1",i=~".*",j="foo"-8              42             39             -7.14%
BenchmarkHeadPostingForMatchers/n="1",i=~".*",i!="2",j="foo"-8       52             42             -19.23%
BenchmarkHeadPostingForMatchers/n="1",i!=""-8                        251069         100101         -60.13%
BenchmarkHeadPostingForMatchers/n="1",i!="",j="foo"-8                251473         100101         -60.19%
BenchmarkHeadPostingForMatchers/n="1",i=~".+",j="foo"-8              250914         100102         -60.11%
BenchmarkHeadPostingForMatchers/n="1",i=~"1.+",j="foo"-8             30038          11181          -62.78%
BenchmarkHeadPostingForMatchers/n="1",i=~".+",i!="2",j="foo"-8       250813         100105         -60.09%
BenchmarkHeadPostingForMatchers/n="1",i=~".+",i!~"2.*",j="foo"-8     281503         111260         -60.48%

benchmark                                                            old bytes     new bytes     delta
BenchmarkHeadPostingForMatchers/n="1"-8                              10887600      10887600      +0.00%
BenchmarkHeadPostingForMatchers/n="1",j="foo"-8                      5456416       5456416       +0.00%
BenchmarkHeadPostingForMatchers/j="foo",n="1"-8                      5456416       5456416       +0.00%
BenchmarkHeadPostingForMatchers/n="1",j!="foo"-8                     5456640       5456544       -0.00%
BenchmarkHeadPostingForMatchers/i=~".*"-8                            258254504     258254472     -0.00%
BenchmarkHeadPostingForMatchers/i=~".+"-8                            520126192     281554792     -45.87%
BenchmarkHeadPostingForMatchers/i=~""-8                              263446640     24908456      -90.55%
BenchmarkHeadPostingForMatchers/i!=""-8                              520121144     281553664     -45.87%
BenchmarkHeadPostingForMatchers/n="1",i=~".*",j="foo"-8              7062448       7062272       -0.00%
BenchmarkHeadPostingForMatchers/n="1",i=~".*",i!="2",j="foo"-8       7063473       7062384       -0.02%
BenchmarkHeadPostingForMatchers/n="1",i!=""-8                        274325656     35793776      -86.95%
BenchmarkHeadPostingForMatchers/n="1",i!="",j="foo"-8                268926824     30362624      -88.71%
BenchmarkHeadPostingForMatchers/n="1",i=~".+",j="foo"-8              268882992     30363000      -88.71%
BenchmarkHeadPostingForMatchers/n="1",i=~"1.+",j="foo"-8             33193401      4269304       -87.14%
BenchmarkHeadPostingForMatchers/n="1",i=~".+",i!="2",j="foo"-8       268875024     30363096      -88.71%
BenchmarkHeadPostingForMatchers/n="1",i=~".+",i!~"2.*",j="foo"-8     300589656     33099784      -88.99%
```

Signed-off-by: Brian Brazil <brian.brazil@robustperception.io>
2019-05-13 10:51:07 +01:00
..
index.go fix some unchecked errors and remove unused vars. (#592) 2019-04-25 13:07:04 +03:00
index_test.go fix some unchecked errors and remove unused vars. (#592) 2019-04-25 13:07:04 +03:00
postings.go Simplify mergedPostings.Seek (#595) 2019-05-13 10:51:07 +01:00
postings_test.go index: reduce empty postings trees (#509) 2019-03-21 18:23:00 +02:00