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Server functionality for HBase
/**
* 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 java.io.IOException;
import java.util.List;
import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import org.apache.hadoop.hbase.classification.InterfaceAudience;
import org.apache.hadoop.conf.Configuration;
import org.apache.hadoop.hbase.TableName;
import org.apache.hadoop.hbase.HConstants;
import org.apache.hadoop.hbase.HTableDescriptor;
/**
* Split size is the number of regions that are on this server that all are
* of the same table, cubed, times 2x the region flush size OR the maximum
* region split size, whichever is smaller. For example, if the flush size
* is 128M, then after two flushes (256MB) we will split which will make two regions
* that will split when their size is 2^3 * 128M*2 = 2048M. If one of these
* regions splits, then there are three regions and now the split size is
* 3^3 * 128M*2 = 6912M, and so on until we reach the configured
* maximum filesize and then from there on out, we'll use that.
*/
@InterfaceAudience.Private
public class IncreasingToUpperBoundRegionSplitPolicy
extends ConstantSizeRegionSplitPolicy {
static final Log LOG =
LogFactory.getLog(IncreasingToUpperBoundRegionSplitPolicy.class);
private long initialSize;
@Override
protected void configureForRegion(HRegion region) {
super.configureForRegion(region);
Configuration conf = getConf();
this.initialSize = conf.getLong("hbase.increasing.policy.initial.size", -1);
if (this.initialSize > 0) {
return;
}
HTableDescriptor desc = region.getTableDesc();
if (desc != null) {
this.initialSize = 2*desc.getMemStoreFlushSize();
}
if (this.initialSize <= 0) {
this.initialSize = 2*conf.getLong(HConstants.HREGION_MEMSTORE_FLUSH_SIZE,
HTableDescriptor.DEFAULT_MEMSTORE_FLUSH_SIZE);
}
}
@Override
protected boolean shouldSplit() {
boolean force = region.shouldForceSplit();
boolean foundABigStore = false;
// Get count of regions that have the same common table as this.region
int tableRegionsCount = getCountOfCommonTableRegions();
// Get size to check
long sizeToCheck = getSizeToCheck(tableRegionsCount);
for (Store store : region.getStores().values()) {
// If any of the stores is unable to split (eg they contain reference files)
// then don't split
if ((!store.canSplit())) {
return false;
}
// Mark if any store is big enough
long size = store.getSize();
if (size > sizeToCheck) {
LOG.debug("ShouldSplit because " + store.getColumnFamilyName() +
" size=" + size + ", sizeToCheck=" + sizeToCheck +
", regionsWithCommonTable=" + tableRegionsCount);
foundABigStore = true;
}
}
return foundABigStore | force;
}
/**
* @return Region max size or count of regions squared * flushsize, which ever is
* smaller; guard against there being zero regions on this server.
*/
protected long getSizeToCheck(final int tableRegionsCount) {
// safety check for 100 to avoid numerical overflow in extreme cases
return tableRegionsCount == 0 || tableRegionsCount > 100 ? getDesiredMaxFileSize():
Math.min(getDesiredMaxFileSize(),
this.initialSize * tableRegionsCount * tableRegionsCount * tableRegionsCount);
}
/**
* @return Count of regions on this server that share the table this.region
* belongs to
*/
private int getCountOfCommonTableRegions() {
RegionServerServices rss = this.region.getRegionServerServices();
// Can be null in tests
if (rss == null) return 0;
TableName tablename = this.region.getTableDesc().getTableName();
int tableRegionsCount = 0;
try {
List hri = rss.getOnlineRegions(tablename);
tableRegionsCount = hri == null || hri.isEmpty()? 0: hri.size();
} catch (IOException e) {
LOG.debug("Failed getOnlineRegions " + tablename, e);
}
return tableRegionsCount;
}
}