[Neo4j] Index Performance(Was: Event framework has landed)

Mattias Persson mattias at neotechnology.com
Thu Jun 24 09:43:30 CEST 2010


2010/6/23 Atle Prange <atle.prange at gmail.com>

> Hm, i'll have to fix that...
>
> Any thoughts on a Trie implementation? Would it be able to compete?
>
> I have no idea on performance or what would be the best approach. I though
your alphabet-relationship-types approach sounded quite interesting. Or as a
b-tree or some other ??-tree.
>
> atle
>
>
>
>
> On Wed, Jun 23, 2010 at 11:04 AM, Mattias Persson
> <mattias at neotechnology.com> wrote:
> > I think the lucene test is flawed since it never returns any results in
> > lookup method. That's why it's so fast :)
> >
> > 2010/6/22 Atle Prange <atle.prange at gmail.com>
> >
> >> Started a new thread since the old got a bit long, if you want to
> >> catch up read the thread "The event framework has landed".
> >>
> >> Okay, i changed the tests to reflect a bit more realistic usage.
> >>
> >> The tests first inserts 1M entries to create a base of data. After
> >> that it makes reads and writes 1000 entries a thousand times.
> >>
> >> BabuDB:
> >> First million: 4s
> >> 1000 inserts, 4ms
> >> 1000 lookups: 30ms
> >>
> >> Lucene:
> >> First million entries took 1 ms. This shows the async behavior of
> Lucene.
> >> 1000 inserts: about 4 seconds (!)
> >> 1000 lookups: under 1 ms.
> >>
> >> (All numbers extremely approximated, and the numbers can only be seen
> >> as relative performance indicators)
> >>
> >>
> >> This is what i excpected. Lucene is optimized towards collecting large
> >> amount of data batchwise, and then handle many searches. (Correct me
> >> if i am wrong)
> >> BabuDB "just writes" data and "just reads" them later on.
> >>
> >> The test can of course be flawed.
> >>
> >> BabuDB test:
> >>
> >>
> >>
> >> package org.ogrm.test;
> >>
> >> import java.io.File;
> >> import java.io.IOException;
> >> import java.util.Iterator;
> >> import java.util.Map.Entry;
> >>
> >> import org.apache.commons.lang.math.RandomUtils;
> >> import org.xtreemfs.babudb.BabuDB;
> >> import org.xtreemfs.babudb.BabuDBException;
> >> import org.xtreemfs.babudb.BabuDBFactory;
> >> import org.xtreemfs.babudb.config.BabuDBConfig;
> >> import org.xtreemfs.babudb.log.DiskLogger.SyncMode;
> >> import org.xtreemfs.babudb.lsmdb.BabuDBInsertGroup;
> >> import org.xtreemfs.babudb.lsmdb.Database;
> >>
> >> public class TestBabuDb {
> >>
> >>        private static Database db;
> >>
> >>        public static void main( String[] args ) throws Exception {
> >>                deleteFileOrDirectory( new File( "babudb" ) );
> >>                BabuDB babuDb = BabuDBFactory.createBabuDB( new
> >> BabuDBConfig(
> >> "babudb/db", "babudb/log", 1, 1024 * 1024 * 20,
> >>                                10, SyncMode.ASYNC, 0, 0, false, 512,
> 1024 *
> >> 1024 * 100 ) );
> >>                db = babuDb.getDatabaseManager().createDatabase( "test",
> 1
> >> );
> >>                int init = 1000000;
> >>                int num = 1000;
> >>                int base = 0;
> >>                int iterations = 1000;
> >>                insert( init, base );
> >>                base = init;
> >>                for (int i = 0; i < iterations; i++) {
> >>                        lookup( num, base );
> >>                        insert( num, base );
> >>                        base = base + num;
> >>                }
> >>
> >>                db.shutdown();
> >>                babuDb.shutdown();
> >>        }
> >>
> >>        private static byte[] fastToBytes( long value ) throws
> IOException {
> >>                byte[] array = new byte[8];
> >>                for (int i = 0; i < 8; i++) {
> >>                        array[7 - i] = (byte) (value >>> (i * 8));
> >>                }
> >>                return array;
> >>        }
> >>
> >>        private static long fastToLong( byte[] array ) throws IOException
> {
> >>                long value = 0;
> >>                for (int i = 0; i < array.length; i++) {
> >>                        value <<= 8;
> >>                        value ^= (long) array[i] & 0xFF;
> >>                }
> >>                return value;
> >>        }
> >>
> >>        private static byte[] lookupKey( String key, Object value ) {
> >>                return String.valueOf( key + "|" + value + "|"
> ).getBytes();
> >>        }
> >>
> >>        private static byte[] key( long id, String key, Object value ) {
> >>                return String.valueOf( key + "|" + value + "|" + id
> >> ).getBytes();
> >>        }
> >>
> >>        private static void lookup( int num, int start ) throws Exception
> {
> >>                long t = System.currentTimeMillis();
> >>                for (int i = start; i < (start + num); i++) {
> >>                        Iterator<Entry<byte[], byte[]>> entries =
> >> db.prefixLookup( 0,
> >> lookupKey( "key", "value" + i ), null ).get();
> >>                        while (entries.hasNext()) {
> >>                                Entry<byte[], byte[]> entry =
> >> entries.next();
> >>                                fastToLong( entry.getValue() );
> >>                        }
> >>                }
> >>                System.out.println( num + " lookups:" +
> >> (System.currentTimeMillis() - t) );
> >>        }
> >>
> >>        private static void insert( int num, int start ) throws Exception
> {
> >>                long t = System.currentTimeMillis();
> >>                BabuDBInsertGroup group = db.createInsertGroup();
> >>
> >>                for (int i = start; i < (num + start); i++) {
> >>                        long id = i;
> >>                        group.addInsert( 0, key( id, "key", "value" + i %
> >> 10000 ),
> >> fastToBytes( id ) );
> >>                }
> >>                db.insert( group, null ).get();
> >>                System.out.println( "insert time (" + num + "):" +
> >> (System.currentTimeMillis() - t) );
> >>        }
> >>
> >>        public static void deleteFileOrDirectory( File file ) {
> >>                if (!file.exists()) {
> >>                        return;
> >>                }
> >>
> >>                if (file.isDirectory()) {
> >>                        for (File child : file.listFiles()) {
> >>                                deleteFileOrDirectory( child );
> >>                        }
> >>                        file.delete();
> >>                } else {
> >>                        file.delete();
> >>                }
> >>        }
> >>
> >>        private static long randomId() {
> >>                return RandomUtils.nextLong();
> >>        }
> >> }
> >>
> >>
> >> TestLucene
> >>
> >>
> >> package org.ogrm.test;
> >>
> >> import java.io.File;
> >> import java.io.IOException;
> >>
> >> import org.apache.lucene.analysis.KeywordAnalyzer;
> >> import org.apache.lucene.document.Document;
> >> import org.apache.lucene.document.Field;
> >> import org.apache.lucene.document.Field.Index;
> >> import org.apache.lucene.document.Field.Store;
> >> import org.apache.lucene.index.IndexReader;
> >> import org.apache.lucene.index.IndexWriter;
> >> import org.apache.lucene.index.Term;
> >> import org.apache.lucene.index.IndexWriter.MaxFieldLength;
> >> import org.apache.lucene.search.IndexSearcher;
> >> import org.apache.lucene.search.Query;
> >> import org.apache.lucene.search.ScoreDoc;
> >> import org.apache.lucene.search.TermQuery;
> >> import org.apache.lucene.search.TopDocs;
> >> import org.apache.lucene.store.Directory;
> >> import org.apache.lucene.store.FSDirectory;
> >>
> >> public class TestLucene {
> >>        private static IndexWriter writer;
> >>        private static IndexSearcher searcher;
> >>
> >>        public static void main( String[] args ) throws Exception {
> >>                File path = new File( "lcn" );
> >>                deleteFileOrDirectory( path );
> >>                Directory dir = FSDirectory.open( path );
> >>                writer = new IndexWriter( dir, new KeywordAnalyzer(),
> >> MaxFieldLength.UNLIMITED );
> >>                writer.setMaxBufferedDocs( 100000 );
> >>
> >>                IndexReader reader = writer.getReader();
> >>                searcher = new IndexSearcher( reader );
> >>
> >>                int init = 1000000;
> >>                int num = 1000;
> >>                int base = 0;
> >>                int iterations = 1000;
> >>                insert( init, base );
> >>                base = init;
> >>                for (int i = 0; i < iterations; i++) {
> >>                        lookup( num, base );
> >>                        insert( num, base );
> >>                        base = base + num;
> >>                }
> >>        }
> >>
> >>        public static void deleteFileOrDirectory( File file ) {
> >>                if (!file.exists()) {
> >>                        return;
> >>                }
> >>
> >>                if (file.isDirectory()) {
> >>                        for (File child : file.listFiles()) {
> >>                                deleteFileOrDirectory( child );
> >>                        }
> >>                        file.delete();
> >>                } else {
> >>                        file.delete();
> >>                }
> >>        }
> >>
> >>        private static void insert( int num, int base ) throws Exception
> {
> >>                long t = System.currentTimeMillis();
> >>                for (int i = num; i < (num + base); i++) {
> >>                        Document doc = new Document();
> >>                        doc.add( new Field( "_id_", fastToBytes( i ),
> >> Store.YES ) );
> >>                        doc.add( new Field( "key", "value" + i % 10000,
> >> Store.NO,
> >> Index.NOT_ANALYZED ) );
> >>                        writer.addDocument( doc );
> >>                }
> >>                writer.commit();
> >>                System.out.println( num + " inserts in " +
> >> (System.currentTimeMillis() - t) );
> >>        }
> >>
> >>        private static void lookup( int num, int base ) throws Exception
> {
> >>                long t = System.currentTimeMillis();
> >>                for (int i = 0; i < 100; i++) {
> >>                        Query query = new TermQuery( new Term( "key",
> >> "value" + (i + 2500000) ) );
> >>                        TopDocs docs = searcher.search( query, 100 );
> >>                        for (ScoreDoc scoreDoc : docs.scoreDocs) {
> >>                                Document doc = searcher.doc( scoreDoc.doc
> );
> >>                                fastToLong( doc.getBinaryValue( "_id_" )
> );
> >>                        }
> >>                }
> >>                System.out.println( num + " get " +
> >> (System.currentTimeMillis() - t) );
> >>        }
> >>
> >>        private static byte[] fastToBytes( long value ) throws
> IOException {
> >>                byte[] array = new byte[8];
> >>                for (int i = 0; i < 8; i++) {
> >>                        array[7 - i] = (byte) (value >>> (i * 8));
> >>                }
> >>                return array;
> >>        }
> >>
> >>        private static long fastToLong( byte[] array ) throws IOException
> {
> >>                long value = 0;
> >>                for (int i = 0; i < array.length; i++) {
> >>                        value <<= 8;
> >>                        value ^= (long) array[i] & 0xFF;
> >>                }
> >>                return value;
> >>        }
> >> }
> >>
> >>
> >>
> >> -atle
> >> _______________________________________________
> >> Neo4j mailing list
> >> User at lists.neo4j.org
> >> https://lists.neo4j.org/mailman/listinfo/user
> >>
> >
> >
> >
> > --
> > Mattias Persson, [mattias at neotechnology.com]
> > Hacker, Neo Technology
> > www.neotechnology.com
> > _______________________________________________
> > Neo4j mailing list
> > User at lists.neo4j.org
> > https://lists.neo4j.org/mailman/listinfo/user
> >
> _______________________________________________
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>



-- 
Mattias Persson, [mattias at neotechnology.com]
Hacker, Neo Technology
www.neotechnology.com


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