So I am doing a lot of random reads and I am getting only 1-2 lookups per
second where I used to get thousands per second. I did an HPROF and found
that the root cause relates to the Sun http protocol handler not handling
InputStream.skip() correctly. So every time it looks up a block it reads
the whole file across the network.
Anyone have any suggestions on how to improve this? Maybe use the Apache
HTTP Client instead of sun.net?
Here¹s a sample stack (Derby 10.8):
TRACE 373064:
java.net.SocketInputStream.socketRead0(SocketInputStream.java:Unknown
line)
java.net.SocketInputStream.read(SocketInputStream.java:129)
java.io.BufferedInputStream.fill(BufferedInputStream.java:218)
java.io.BufferedInputStream.read1(BufferedInputStream.java:258)
java.io.BufferedInputStream.read(BufferedInputStream.java:317)
sun.net.www.MeteredStream.read(MeteredStream.java:116)
java.io.FilterInputStream.read(FilterInputStream.java:116)
sun.net.www.protocol.http.HttpURLConnection$HttpInputStream.read(HttpURLConn
ection.java:2672)
sun.net.www.protocol.http.HttpURLConnection$HttpInputStream.skip(HttpURLConn
ection.java:2719)
org.apache.derby.iapi.services.io.InputStreamUtil.skipPersistent(InputStream
Util.java:169)
org.apache.derby.iapi.services.io.InputStreamUtil.skipFully(InputStreamUtil.
java:147)
org.apache.derby.impl.store.raw.data.InputStreamContainer.readPositionedPage
(InputStreamContainer.java:208)
org.apache.derby.impl.store.raw.data.InputStreamContainer.readPage(InputStre
amContainer.java:186)
org.apache.derby.impl.store.raw.data.CachedPage.readPage(CachedPage.java:673
)
org.apache.derby.impl.store.raw.data.CachedPage.setIdentity(CachedPage.java:
193)
org.apache.derby.impl.services.cache.ConcurrentCache.find(ConcurrentCache.ja
va:295)
org.apache.derby.impl.store.raw.data.FileContainer.getUserPage(FileContainer
.java:2541)
org.apache.derby.impl.store.raw.data.FileContainer.getPage(FileContainer.jav
a:2591)
org.apache.derby.impl.store.raw.data.BaseContainerHandle.getPage(BaseContain
erHandle.java:319)
org.apache.derby.impl.store.access.conglomerate.OpenConglomerate.latchPage(O
penConglomerate.java:308)
org.apache.derby.impl.store.access.conglomerate.GenericConglomerateControlle
r.fetch(GenericConglomerateController.java:263)
org.apache.derby.impl.sql.execute.IndexRowToBaseRowResultSet.getNextRowCore(
IndexRowToBaseRowResultSet.java:389)
org.apache.derby.impl.sql.execute.BasicNoPutResultSetImpl.getNextRow(BasicNo
PutResultSetImpl.java:478)
org.apache.derby.impl.jdbc.EmbedResultSet.movePosition(EmbedResultSet.java:4
30)
org.apache.derby.impl.jdbc.EmbedResultSet.next(EmbedResultSet.java:374)
com.icrossing.collection.ipinfo.derby.DerbyQuery.run(DerbyQuery.java:90)
java.lang.Thread.run(Thread.java:680)
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