rdf

README

go tool pprof --alloc_objects uidassigner heap.prof

(pprof) top10
196427053 of 207887723 total (94.49%)
Dropped 41 nodes (cum <= 1039438)
Showing top 10 nodes out of 31 (cum >= 8566234)
      flat  flat%   sum%        cum   cum%
  55529704 26.71% 26.71%   55529704 26.71%  github.com/dgraph-io/dgraph/rdf.Parse
  28255068 13.59% 40.30%   30647245 14.74%  github.com/dgraph-io/dgraph/posting.(*List).getPostingList
  20406729  9.82% 50.12%   20406729  9.82%  github.com/zond/gotomic.newRealEntryWithHashCode
  17777182  8.55% 58.67%   17777182  8.55%  strings.makeCutsetFunc
  17582839  8.46% 67.13%   17706815  8.52%  github.com/dgraph-io/dgraph/loader.(*state).readLines
  15139047  7.28% 74.41%   88445933 42.55%  github.com/dgraph-io/dgraph/loader.(*state).parseStream
  12927366  6.22% 80.63%   12927366  6.22%  github.com/zond/gotomic.(*element).search
  10789028  5.19% 85.82%   66411362 31.95%  github.com/dgraph-io/dgraph/posting.GetOrCreate
   9453856  4.55% 90.37%    9453856  4.55%  github.com/zond/gotomic.(*hashHit).search
   8566234  4.12% 94.49%    8566234  4.12%  github.com/dgraph-io/dgraph/uid.stringKey


(pprof) list rdf.Parse
Total: 207887723
ROUTINE ======================== github.com/dgraph-io/dgraph/rdf.Parse in /home/mrjn/go/src/github.com/dgraph-io/dgraph/rdf/parse.go
  55529704   55529704 (flat, cum) 26.71% of Total
         .          .    118:	}
         .          .    119:	return val[1 : len(val)-1]
         .          .    120:}
         .          .    121:
         .          .    122:func Parse(line string) (rnq NQuad, rerr error) {
  54857942   54857942    123:	l := lex.NewLexer(line)
         .          .    124:	go run(l)
         .          .    125:	var oval string
         .          .    126:	var vend bool


This showed that lex.NewLexer(..) was pretty expensive in terms of memory allocation.
So, let's use sync.Pool here.

After using sync.Pool, this is the output:

422808936 of 560381333 total (75.45%)
Dropped 63 nodes (cum <= 2801906)
Showing top 10 nodes out of 62 (cum >= 18180150)
      flat  flat%   sum%        cum   cum%
 103445194 18.46% 18.46%  103445194 18.46%  github.com/Sirupsen/logrus.(*Entry).WithFields
  65448918 11.68% 30.14%  163184489 29.12%  github.com/Sirupsen/logrus.(*Entry).WithField
  48366300  8.63% 38.77%  203838187 36.37%  github.com/dgraph-io/dgraph/posting.(*List).get
  39789719  7.10% 45.87%   49276181  8.79%  github.com/dgraph-io/dgraph/posting.(*List).getPostingList
  36642638  6.54% 52.41%   36642638  6.54%  github.com/dgraph-io/dgraph/lex.NewLexer
  35190301  6.28% 58.69%   35190301  6.28%  github.com/google/flatbuffers/go.(*Builder).growByteBuffer
  31392455  5.60% 64.29%   31392455  5.60%  github.com/zond/gotomic.newRealEntryWithHashCode
  25895676  4.62% 68.91%   25895676  4.62%  github.com/zond/gotomic.(*element).search
  18546971  3.31% 72.22%   72863016 13.00%  github.com/dgraph-io/dgraph/loader.(*state).parseStream
  18090764  3.23% 75.45%   18180150  3.24%  github.com/dgraph-io/dgraph/loader.(*state).readLines

After a few more discussions, I realized that lexer didn't need to be allocated on the heap.
So, I switched it to be allocated on stack. These are the results.

$ go tool pprof uidassigner heap.prof 
Entering interactive mode (type "help" for commands)
(pprof) top10
1308.70MB of 1696.59MB total (77.14%)
Dropped 73 nodes (cum <= 8.48MB)
Showing top 10 nodes out of 52 (cum >= 161.50MB)
      flat  flat%   sum%        cum   cum%
  304.56MB 17.95% 17.95%   304.56MB 17.95%  github.com/dgraph-io/dgraph/posting.NewList
  209.55MB 12.35% 30.30%   209.55MB 12.35%  github.com/Sirupsen/logrus.(*Entry).WithFields
  207.55MB 12.23% 42.54%   417.10MB 24.58%  github.com/Sirupsen/logrus.(*Entry).WithField
     108MB  6.37% 48.90%      108MB  6.37%  github.com/dgraph-io/dgraph/uid.(*lockManager).newOrExisting
      88MB  5.19% 54.09%       88MB  5.19%  github.com/zond/gotomic.newMockEntry
   85.51MB  5.04% 59.13%    85.51MB  5.04%  github.com/google/flatbuffers/go.(*Builder).growByteBuffer
   78.01MB  4.60% 63.73%    78.01MB  4.60%  github.com/dgraph-io/dgraph/posting.Key
   78.01MB  4.60% 68.32%    78.51MB  4.63%  github.com/dgraph-io/dgraph/uid.stringKey
      76MB  4.48% 72.80%       76MB  4.48%  github.com/zond/gotomic.newRealEntryWithHashCode
   73.50MB  4.33% 77.14%   161.50MB  9.52%  github.com/zond/gotomic.(*Hash).getBucketByIndex

Now, rdf.Parse is no longer shows up in memory profiler. Win!

Documentation

Overview

Package rdf package parses N-Quad statements based on http://www.w3.org/TR/n-quads/

Index

• type NQuad
  • func Parse(line string) (rnq NQuad, rerr error)
  • func (nq NQuad) ToEdge() (result x.DirectedEdge, rerr error)
  • func (nq NQuad) ToEdgeUsing(xidToUID map[string]uint64) (result x.DirectedEdge, rerr error)

Types

type NQuad

type NQuad struct {
	Subject     string
	Predicate   string
	ObjectId    string
	ObjectValue []byte
	Label       string
}

NQuad is the data structure used for storing rdf N-Quads.

func Parse

func Parse(line string) (rnq NQuad, rerr error)

Parse parses a mutation string and returns the NQuad representation for it.

func (NQuad) ToEdge

func (nq NQuad) ToEdge() (result x.DirectedEdge, rerr error)

ToEdge is useful when you want to find the UID corresponding to XID for just one edge. The method doesn't automatically generate a UID for an XID.

func (NQuad) ToEdgeUsing

func (nq NQuad) ToEdgeUsing(
	xidToUID map[string]uint64) (result x.DirectedEdge, rerr error)

ToEdgeUsing determines the UIDs for the provided XIDs and populates the xidToUid map.