Package org.apache.bookkeeper.bookie.datainteg

Class EntryCopierImpl

java.lang.Object

org.apache.bookkeeper.bookie.datainteg.EntryCopierImpl

All Implemented Interfaces:

EntryCopier

public class EntryCopierImpl
extends java.lang.Object
implements EntryCopier

Implementation for the EntryCopier interface. Handles the reading of entries from peer bookies.

Nested Class Summary

Nested Classes

Modifier and Type	Class	Description
(package private) class	EntryCopierImpl.BatchImpl
(package private) static class	EntryCopierImpl.SinBin

Nested classes/interfaces inherited from interface org.apache.bookkeeper.bookie.datainteg.EntryCopier

EntryCopier.Batch

Constructor Summary

Constructors

Constructor	Description
EntryCopierImpl(BookieId bookieId, BookieClient bookieClient, LedgerStorage storage, com.google.common.base.Ticker ticker)

Method Summary

Modifier and Type	Method	Description
EntryCopier.Batch	newBatch(long ledgerId, LedgerMetadata metadata)	Start copying a new batch.
(package private) static com.google.common.collect.ImmutableSortedMap<java.lang.Long,com.google.common.collect.ImmutableList<java.lang.Integer>>	preferredBookieIndices(BookieId bookieId, LedgerMetadata metadata, java.util.Set<BookieId> errorBookies, long seed)	Generate a map of preferred bookie indices.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

EntryCopierImpl

public EntryCopierImpl(BookieId bookieId,
                       BookieClient bookieClient,
                       LedgerStorage storage,
                       com.google.common.base.Ticker ticker)

Method Detail

newBatch

public EntryCopier.Batch newBatch(long ledgerId,
                                  LedgerMetadata metadata)
                           throws java.io.IOException

Description copied from interface: EntryCopier

Start copying a new batch. In general, there should be a batch per ledger.

Specified by:

newBatch in interface EntryCopier

Throws:

java.io.IOException

preferredBookieIndices

static com.google.common.collect.ImmutableSortedMap<java.lang.Long,com.google.common.collect.ImmutableList<java.lang.Integer>> preferredBookieIndices(BookieId bookieId,
                                                                                                                                                            LedgerMetadata metadata,
                                                                                                                                                            java.util.Set<BookieId> errorBookies,
                                                                                                                                                            long seed)

Generate a map of preferred bookie indices. For each ensemble, generate the order in which bookies should be tried for entries, notwithstanding errors. For example, if a e5,w2,a2 ensemble has the bookies: [bookie1, bookie2, bookie3, bookie4, bookie5] and the current bookie is bookie2, then we should return something like: [4, 2, 0, 3] Then when retrieving an entry, even though it is only written to 2, we try the bookie in the order from this list. This will cause more requests to go to the same bookie, which should give us the benefit of read locality. We don't want to simply sort by bookie id, as that would cause the same bookies to be loaded for all ensembles. Bookies which have presented errors are always tried last.