[
https://issues.apache.org/jira/browse/SQOOP-1312?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel
]
Jong Ho Lee updated SQOOP-1312:
-------------------------------
Comment: was deleted
(was: /**
* 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.
*/
// modified by Jongho Lee at Samsung SDS. ([email protected])
package org.apache.sqoop.mapreduce.db;
import java.math.BigDecimal;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.util.ArrayList;
import java.util.List;
import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import org.apache.hadoop.conf.Configuration;
import org.apache.hadoop.mapreduce.InputSplit;
import com.cloudera.sqoop.config.ConfigurationHelper;
import com.cloudera.sqoop.mapreduce.db.DBSplitter;
import com.cloudera.sqoop.mapreduce.db.DataDrivenDBInputFormat;
/**
* Implement DBSplitter over BigDecimal values.
*/
public class BigDecimalSplitter implements DBSplitter {
private static final Log LOG = LogFactory.getLog(BigDecimalSplitter.class);
public List<InputSplit> split(Configuration conf, ResultSet results,
String colName) throws SQLException {
BigDecimal minVal = results.getBigDecimal(1);
BigDecimal maxVal = results.getBigDecimal(2);
String lowClausePrefix = colName + " >= ";
String highClausePrefix = colName + " < ";
BigDecimal numSplits = new BigDecimal(
ConfigurationHelper.getConfNumMaps(conf));
if (minVal == null && maxVal == null) {
// Range is null to null. Return a null split accordingly.
List<InputSplit> splits = new ArrayList<InputSplit>();
splits.add(new DataDrivenDBInputFormat.DataDrivenDBInputSplit(
colName + " IS NULL", colName + " IS NULL"));
return splits;
}
if (minVal == null || maxVal == null) {
// Don't know what is a reasonable min/max value for interpolation. Fail.
LOG.error("Cannot find a range for NUMERIC or DECIMAL "
+ "fields with one end NULL.");
return null;
}
// Get all the split points together.
List<BigDecimal> splitPoints = split(numSplits, minVal, maxVal);
List<InputSplit> splits = new ArrayList<InputSplit>();
// Turn the split points into a set of intervals.
BigDecimal start = splitPoints.get(0);
for (int i = 1; i < splitPoints.size(); i++) {
BigDecimal end = splitPoints.get(i);
if (i == splitPoints.size() - 1) {
// This is the last one; use a closed interval.
splits.add(new DataDrivenDBInputFormat.DataDrivenDBInputSplit(
lowClausePrefix + start.toString(),
colName + " <= " + end.toString()));
} else {
// Normal open-interval case.
splits.add(new DataDrivenDBInputFormat.DataDrivenDBInputSplit(
lowClausePrefix + start.toString(),
highClausePrefix + end.toString()));
}
start = end;
}
return splits;
}
private static final BigDecimal MIN_INCREMENT =
new BigDecimal(10000 * Double.MIN_VALUE);
/**
* Divide numerator by denominator. If impossible in exact mode, use rounding.
*/
protected BigDecimal tryDivide(BigDecimal numerator, BigDecimal denominator) {
try {
return numerator.divide(denominator);
} catch (ArithmeticException ae) {
return numerator.divide(denominator, BigDecimal.ROUND_HALF_UP);
}
}
/**
* Returns a list of BigDecimals one element longer than the list of input
* splits. This represents the boundaries between input splits. All splits
* are open on the top end, except the last one.
*
* So the list [0, 5, 8, 12, 18] would represent splits capturing the
* intervals:
*
* [0, 5)
* [5, 8)
* [8, 12)
* [12, 18] note the closed interval for the last split.
*/
protected List<BigDecimal> split(BigDecimal numSplits, BigDecimal minVal,
BigDecimal maxVal) throws SQLException {
List<BigDecimal> splits = new ArrayList<BigDecimal>();
// Use numSplits as a hint. May need an extra task if the size doesn't
// divide cleanly.
BigDecimal splitSize = tryDivide(maxVal.subtract(minVal), (numSplits));
if (splitSize.compareTo(MIN_INCREMENT) < 0) {
splitSize = MIN_INCREMENT;
LOG.warn("Set BigDecimal splitSize to MIN_INCREMENT");
}
BigDecimal curVal = minVal;
for (int i = 0; i < numSplits - 1; i++) {
// while (curVal.compareTo(maxVal) <= 0) {
// modified: while-loop is replaced with for-loop and if-condition.
if (curVal.compareTo(maxVal) > 0)
break;
splits.add(curVal);
curVal = curVal.add(splitSize);
}
if (splits.get(splits.size() - 1).compareTo(maxVal) != 0
|| splits.size() == 1) {
// We didn't end on the maxVal. Add that to the end of the list.
splits.add(maxVal);
}
return splits;
}
}
)
> One of mappers does not load data from mySql if double column is used as
> split key
> ----------------------------------------------------------------------------------
>
> Key: SQOOP-1312
> URL: https://issues.apache.org/jira/browse/SQOOP-1312
> Project: Sqoop
> Issue Type: Bug
> Affects Versions: 1.4.4
> Reporter: Jong Ho Lee
> Labels: sourcecode
>
> When we used Sqoop to load data from mySQL using one double column as
> split-key in Samsung SDS,
> the last mapper did not load data from mySQL at all.
> The number of mappers was sometimes increased by 1.
> I think they were caused by some bugs in FloatSplitter.java
> For the last split, lowClausePrefix + Double.toString(curUpper), may be
> lowClausePrefix + Double.toString(curLower).
> In while (curUpper < maxVal) loop, because of round-off error,
> minVal + splitSize * numSplits can be smaller than maxVal.
> Therefore, using for-loop would be better.
> Attached is a proposed new FloatSplitter.java
> {code}
> /**
> * 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.
> */
> // modified by Jongho Lee at Samsung SDS.
> package org.apache.sqoop.mapreduce.db;
> import java.sql.ResultSet;
> import java.sql.SQLException;
> import java.util.ArrayList;
> import java.util.List;
> import org.apache.commons.logging.Log;
> import org.apache.commons.logging.LogFactory;
> import org.apache.hadoop.conf.Configuration;
> import org.apache.hadoop.mapreduce.InputSplit;
> import com.cloudera.sqoop.config.ConfigurationHelper;
> import com.cloudera.sqoop.mapreduce.db.DBSplitter;
> import com.cloudera.sqoop.mapreduce.db.DataDrivenDBInputFormat;
> /**
> * Implement DBSplitter over floating-point values.
> */
> public class FloatSplitter implements DBSplitter {
> private static final Log LOG = LogFactory.getLog(FloatSplitter.class);
> private static final double MIN_INCREMENT = 10000 * Double.MIN_VALUE;
> public List<InputSplit> split(Configuration conf, ResultSet results,
> String colName) throws SQLException {
> LOG.warn("Generating splits for a floating-point index column. Due to
> the");
> LOG.warn("imprecise representation of floating-point values in Java,
> this");
> LOG.warn("may result in an incomplete import.");
> LOG.warn("You are strongly encouraged to choose an integral split
> column.");
> List<InputSplit> splits = new ArrayList<InputSplit>();
> if (results.getString(1) == null && results.getString(2) == null) {
> // Range is null to null. Return a null split accordingly.
> splits.add(new DataDrivenDBInputFormat.DataDrivenDBInputSplit(
> colName + " IS NULL", colName + " IS NULL"));
> return splits;
> }
> double minVal = results.getDouble(1);
> double maxVal = results.getDouble(2);
> // Use this as a hint. May need an extra task if the size doesn't
> // divide cleanly.
> int numSplits = ConfigurationHelper.getConfNumMaps(conf);
> double splitSize = (maxVal - minVal) / (double) numSplits;
> if (splitSize < MIN_INCREMENT) {
> splitSize = MIN_INCREMENT;
> }
> String lowClausePrefix = colName + " >= ";
> String highClausePrefix = colName + " < ";
> double curLower = minVal;
> double curUpper = curLower + splitSize;
> for (int i = 0; i < numSplits - 1; i++) {
> // while (curUpper < maxVal) { // changed to for loop
> splits.add(new DataDrivenDBInputFormat.DataDrivenDBInputSplit(
> lowClausePrefix + Double.toString(curLower),
> highClausePrefix + Double.toString(curUpper)));
> curLower = curUpper;
> curUpper += splitSize;
> }
> // Catch any overage and create the closed interval for the last split.
> if (curLower <= maxVal || splits.size() == 1) {
> splits.add(new DataDrivenDBInputFormat.DataDrivenDBInputSplit(
> lowClausePrefix + Double.toString(curLower),
> colName + " <= " + Double.toString(maxVal)));
> // curUpper -> curLower // changed
> }
> if (results.getString(1) == null || results.getString(2) == null) {
> // At least one extrema is null; add a null split.
> splits.add(new DataDrivenDBInputFormat.DataDrivenDBInputSplit(
> colName + " IS NULL", colName + " IS NULL"));
> }
> return splits;
> }
> }
> {code}
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