HBASE-3082 For ICV gets, first look in MemStore before reading StoreFiles (Prakash via jgray)

git-svn-id: https://svn.apache.org/repos/asf/hbase/trunk@1026910 13f79535-47bb-0310-9956-ffa450edef68
This commit is contained in:
Jonathan Gray 2010-10-24 22:36:27 +00:00
parent a574082d85
commit d92252312c
4 changed files with 184 additions and 12 deletions

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@ -1037,6 +1037,8 @@ Release 0.21.0 - Unreleased
HBASE-3132 Print TimestampRange and BloomFilters in HFile pretty print
HBASE-2514 RegionServer should refuse to be assigned a region that use
LZO when LZO isn't available
HBASE-3082 For ICV gets, first look in MemStore before reading StoreFiles
(prakash via stack)
NEW FEATURES
HBASE-1961 HBase EC2 scripts

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@ -2859,6 +2859,86 @@ public class HRegion implements HeapSize { // , Writable{
return new Result(result);
}
/**
* An optimized version of {@link #get(Get)} that checks MemStore first for
* the specified query.
* <p>
* This is intended for use by increment operations where we have the
* guarantee that versions are never inserted out-of-order so if a value
* exists in MemStore it is the latest value.
* <p>
* It only makes sense to use this method without a TimeRange and maxVersions
* equal to 1.
* @param get
* @return result
* @throws IOException
*/
private List<KeyValue> getLastIncrement(final Get get) throws IOException {
InternalScan iscan = new InternalScan(get);
List<KeyValue> results = new ArrayList<KeyValue>();
// memstore scan
iscan.checkOnlyMemStore();
InternalScanner scanner = null;
try {
scanner = getScanner(iscan);
scanner.next(results);
} finally {
if (scanner != null)
scanner.close();
}
// count how many columns we're looking for
int expected = 0;
Map<byte[], NavigableSet<byte[]>> familyMap = get.getFamilyMap();
for (NavigableSet<byte[]> qfs : familyMap.values()) {
expected += qfs.size();
}
// found everything we were looking for, done
if (results.size() == expected) {
return results;
}
// still have more columns to find
if (results != null && !results.isEmpty()) {
// subtract what was found in memstore
for (KeyValue kv : results) {
byte [] family = kv.getFamily();
NavigableSet<byte[]> qfs = familyMap.get(family);
qfs.remove(kv.getQualifier());
if (qfs.isEmpty()) familyMap.remove(family);
expected--;
}
// make a new get for just what is left
Get newGet = new Get(get.getRow());
for (Map.Entry<byte[], NavigableSet<byte[]>> f : familyMap.entrySet()) {
byte [] family = f.getKey();
for (byte [] qualifier : f.getValue()) {
newGet.addColumn(family, qualifier);
}
}
iscan = new InternalScan(newGet);
}
// check store files for what is left
List<KeyValue> fileResults = new ArrayList<KeyValue>();
iscan.checkOnlyStoreFiles();
scanner = null;
try {
scanner = getScanner(iscan);
scanner.next(fileResults);
} finally {
if (scanner != null)
scanner.close();
}
// combine and return
results.addAll(fileResults);
return results;
}
/*
* Do a get based on the get parameter.
*/
@ -2905,7 +2985,7 @@ public class HRegion implements HeapSize { // , Writable{
Get get = new Get(row);
get.addColumn(family, qualifier);
List<KeyValue> results = get(get);
List<KeyValue> results = getLastIncrement(get);
if (!results.isEmpty()) {
KeyValue kv = results.get(0);
@ -2914,7 +2994,7 @@ public class HRegion implements HeapSize { // , Writable{
result += Bytes.toLong(buffer, valueOffset, Bytes.SIZEOF_LONG);
}
// bulid the KeyValue now:
// build the KeyValue now:
KeyValue newKv = new KeyValue(row, family,
qualifier, EnvironmentEdgeManager.currentTimeMillis(),
Bytes.toBytes(result));
@ -2930,7 +3010,7 @@ public class HRegion implements HeapSize { // , Writable{
// Now request the ICV to the store, this will set the timestamp
// appropriately depending on if there is a value in memcache or not.
// returns the
// returns the change in the size of the memstore from operation
long size = store.updateColumnValue(row, family, qualifier, result);
size = this.memstoreSize.addAndGet(size);

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@ -0,0 +1,78 @@
/**
* Copyright 2010 The Apache Software Foundation
*
* Licensed to the Apache Software Foundation (ASF) under one
* or more contributor license agreements. See the NOTICE file
* distributed with this work for additional information
* regarding copyright ownership. The ASF licenses this file
* to you under the Apache License, Version 2.0 (the
* "License"); you may not use this file except in compliance
* with the License. You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package org.apache.hadoop.hbase.regionserver;
import org.apache.hadoop.hbase.client.Get;
import org.apache.hadoop.hbase.client.Scan;
/**
* Special internal-only scanner, currently used for increment operations to
* allow additional server-side arguments for Scan operations.
* <p>
* Rather than adding new options/parameters to the public Scan API, this new
* class has been created.
* <p>
* Supports adding an option to only read from the MemStore with
* {@link #checkOnlyMemStore()} or to only read from StoreFiles with
* {@link #checkOnlyStoreFiles()}.
*/
class InternalScan extends Scan {
private boolean memOnly = false;
private boolean filesOnly = false;
/**
* @param get get to model scan after
*/
public InternalScan(Get get) {
super(get);
}
/**
* StoreFiles will not be scanned. Only MemStore will be scanned.
*/
public void checkOnlyMemStore() {
memOnly = true;
filesOnly = false;
}
/**
* MemStore will not be scanned. Only StoreFiles will be scanned.
*/
public void checkOnlyStoreFiles() {
memOnly = false;
filesOnly = true;
}
/**
* Returns true if only the MemStore should be checked. False if not.
* @return true to only check MemStore
*/
public boolean isCheckOnlyMemStore() {
return (memOnly);
}
/**
* Returns true if only StoreFiles should be checked. False if not.
* @return true if only check StoreFiles
*/
public boolean isCheckOnlyStoreFiles() {
return (filesOnly);
}
}

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@ -27,6 +27,7 @@ import org.apache.hadoop.hbase.client.Scan;
import java.io.IOException;
import java.util.ArrayList;
import java.util.LinkedList;
import java.util.List;
import java.util.NavigableSet;
@ -149,22 +150,33 @@ class StoreScanner implements KeyValueScanner, InternalScanner, ChangedReadersOb
*/
private List<KeyValueScanner> getScanners(Scan scan,
final NavigableSet<byte[]> columns) throws IOException {
boolean memOnly;
boolean filesOnly;
if (scan instanceof InternalScan) {
InternalScan iscan = (InternalScan)scan;
memOnly = iscan.isCheckOnlyMemStore();
filesOnly = iscan.isCheckOnlyStoreFiles();
} else {
memOnly = false;
filesOnly = false;
}
List<KeyValueScanner> scanners = new LinkedList<KeyValueScanner>();
// First the store file scanners
List<StoreFileScanner> sfScanners = StoreFileScanner
if (memOnly == false) {
List<StoreFileScanner> sfScanners = StoreFileScanner
.getScannersForStoreFiles(store.getStorefiles(), cacheBlocks, isGet);
List<KeyValueScanner> scanners =
new ArrayList<KeyValueScanner>(sfScanners.size()+1);
// include only those scan files which pass all filters
for (StoreFileScanner sfs : sfScanners) {
if (sfs.shouldSeek(scan, columns)) {
scanners.add(sfs);
// include only those scan files which pass all filters
for (StoreFileScanner sfs : sfScanners) {
if (sfs.shouldSeek(scan, columns)) {
scanners.add(sfs);
}
}
}
// Then the memstore scanners
if (this.store.memstore.shouldSeek(scan)) {
scanners.addAll(this.store.memstore.getScanners());
if ((filesOnly == false) && (this.store.memstore.shouldSeek(scan))) {
scanners.addAll(this.store.memstore.getScanners());
}
return scanners;
}