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hudi/hoodie-client/src/main/java/com/uber/hoodie/io/HoodieCleaner.java
2017-05-01 21:48:27 -07:00

277 lines
13 KiB
Java

/*
* Copyright (c) 2016 Uber Technologies, Inc. (hoodie-dev-group@uber.com)
*
* Licensed 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 com.uber.hoodie.io;
import com.clearspring.analytics.util.Lists;
import com.google.common.collect.Maps;
import com.uber.hoodie.common.HoodieCleanStat;
import com.uber.hoodie.common.model.HoodieCleaningPolicy;
import com.uber.hoodie.common.model.HoodieDataFile;
import com.uber.hoodie.common.model.HoodieRecordPayload;
import com.uber.hoodie.common.model.HoodieTableType;
import com.uber.hoodie.common.table.HoodieTimeline;
import com.uber.hoodie.common.table.TableFileSystemView;
import com.uber.hoodie.common.table.log.HoodieLogFile;
import com.uber.hoodie.common.table.timeline.HoodieInstant;
import com.uber.hoodie.common.util.FSUtils;
import com.uber.hoodie.config.HoodieWriteConfig;
import com.uber.hoodie.table.HoodieTable;
import org.apache.hadoop.fs.FileStatus;
import org.apache.hadoop.fs.FileSystem;
import org.apache.hadoop.fs.Path;
import org.apache.log4j.LogManager;
import org.apache.log4j.Logger;
import org.apache.spark.api.java.function.FlatMapFunction;
import java.io.IOException;
import java.util.ArrayList;
import java.util.Iterator;
import java.util.List;
import java.util.Map;
import java.util.Optional;
import java.util.function.Function;
import java.util.stream.Collectors;
import java.util.stream.Stream;
/**
* Cleaner is responsible for garbage collecting older files in a given partition path, such that
* <p>
* 1) It provides sufficient time for existing queries running on older versions, to finish
* <p>
* 2) It bounds the growth of the files in the file system
* <p>
* TODO: Should all cleaning be done based on {@link com.uber.hoodie.common.model.HoodieCommitMetadata}
*/
public class HoodieCleaner<T extends HoodieRecordPayload<T>> {
private static Logger logger = LogManager.getLogger(HoodieCleaner.class);
private final TableFileSystemView fileSystemView;
private final HoodieTimeline commitTimeline;
private HoodieTable<T> hoodieTable;
private HoodieWriteConfig config;
private FileSystem fs;
public HoodieCleaner(HoodieTable<T> hoodieTable, HoodieWriteConfig config) {
this.hoodieTable = hoodieTable;
this.fileSystemView = hoodieTable.getCompactedFileSystemView();
this.commitTimeline = hoodieTable.getCompletedCommitTimeline();
this.config = config;
this.fs = hoodieTable.getFs();
}
/**
* Selects the older versions of files for cleaning, such that it bounds the number of versions of each file.
* This policy is useful, if you are simply interested in querying the table, and you don't want too many
* versions for a single file (i.e run it with versionsRetained = 1)
*
* @param partitionPath
* @return
* @throws IOException
*/
private List<String> getFilesToCleanKeepingLatestVersions(String partitionPath)
throws IOException {
logger.info("Cleaning " + partitionPath + ", retaining latest " + config
.getCleanerFileVersionsRetained() + " file versions. ");
List<List<HoodieDataFile>> fileVersions =
fileSystemView.getEveryVersionInPartition(partitionPath)
.collect(Collectors.toList());
List<String> deletePaths = new ArrayList<>();
// Collect all the datafiles savepointed by all the savepoints
List<String> savepointedFiles = hoodieTable.getSavepoints().stream()
.flatMap(s -> hoodieTable.getSavepointedDataFiles(s)).collect(Collectors.toList());
for (List<HoodieDataFile> versionsForFileId : fileVersions) {
int keepVersions = config.getCleanerFileVersionsRetained();
Iterator<HoodieDataFile> commitItr = versionsForFileId.iterator();
while (commitItr.hasNext() && keepVersions > 0) {
// Skip this most recent version
HoodieDataFile next = commitItr.next();
if(savepointedFiles.contains(next.getFileName())) {
// do not clean up a savepoint data file
continue;
}
keepVersions--;
}
// Delete the remaining files
while (commitItr.hasNext()) {
HoodieDataFile nextRecord = commitItr.next();
deletePaths.add(String.format("%s/%s/%s", config.getBasePath(), partitionPath,
nextRecord.getFileName()));
if (hoodieTable.getMetaClient().getTableType()
== HoodieTableType.MERGE_ON_READ) {
// If merge on read, then clean the log files for the commits as well
deletePaths.add(String
.format("%s/%s/%s", config.getBasePath(), partitionPath,
FSUtils.maskWithoutLogVersion(nextRecord.getCommitTime(),
nextRecord.getFileId(),
HoodieLogFile.DELTA_EXTENSION)));
}
}
}
return deletePaths;
}
/**
* Selects the versions for file for cleaning, such that it
* <p>
* - Leaves the latest version of the file untouched
* - For older versions,
* - It leaves all the commits untouched which has occured in last <code>config.getCleanerCommitsRetained()</code> commits
* - It leaves ONE commit before this window. We assume that the max(query execution time) == commit_batch_time * config.getCleanerCommitsRetained(). This is 12 hours by default.
* This is essential to leave the file used by the query thats running for the max time.
* <p>
* This provides the effect of having lookback into all changes that happened in the last X
* commits. (eg: if you retain 24 commits, and commit batch time is 30 mins, then you have 12 hrs of lookback)
* <p>
* This policy is the default.
*
* @param partitionPath
* @return
* @throws IOException
*/
private List<String> getFilesToCleanKeepingLatestCommits(String partitionPath)
throws IOException {
int commitsRetained = config.getCleanerCommitsRetained();
logger.info(
"Cleaning " + partitionPath + ", retaining latest " + commitsRetained + " commits. ");
List<String> deletePaths = new ArrayList<>();
// Collect all the datafiles savepointed by all the savepoints
List<String> savepointedFiles = hoodieTable.getSavepoints().stream()
.flatMap(s -> hoodieTable.getSavepointedDataFiles(s)).collect(Collectors.toList());
// determine if we have enough commits, to start cleaning.
if (commitTimeline.countInstants() > commitsRetained) {
HoodieInstant earliestCommitToRetain =
commitTimeline.nthInstant(commitTimeline.countInstants() - commitsRetained).get();
List<List<HoodieDataFile>> fileVersions =
fileSystemView.getEveryVersionInPartition(partitionPath)
.collect(Collectors.toList());
for (List<HoodieDataFile> fileList : fileVersions) {
String lastVersion = FSUtils.getCommitTime(fileList.get(0).getFileName());
String lastVersionBeforeEarliestCommitToRetain =
getLatestVersionBeforeCommit(fileList, earliestCommitToRetain);
// Ensure there are more than 1 version of the file (we only clean old files from updates)
// i.e always spare the last commit.
for (HoodieDataFile afile : fileList) {
String fileCommitTime = afile.getCommitTime();
if(savepointedFiles.contains(afile.getFileName())) {
// do not clean up a savepoint data file
continue;
}
// Dont delete the latest commit and also the last commit before the earliest commit we are retaining
// The window of commit retain == max query run time. So a query could be running which still
// uses this file.
if (fileCommitTime.equals(lastVersion) || (
lastVersionBeforeEarliestCommitToRetain != null && fileCommitTime
.equals(lastVersionBeforeEarliestCommitToRetain))) {
// move on to the next file
continue;
}
// Always keep the last commit
if (HoodieTimeline.compareTimestamps(
earliestCommitToRetain.getTimestamp(),
fileCommitTime,
HoodieTimeline.GREATER)) {
// this is a commit, that should be cleaned.
deletePaths.add(String
.format("%s/%s/%s", config.getBasePath(), partitionPath, FSUtils
.maskWithoutTaskPartitionId(fileCommitTime, afile.getFileId())));
if (hoodieTable.getMetaClient().getTableType()
== HoodieTableType.MERGE_ON_READ) {
// If merge on read, then clean the log files for the commits as well
deletePaths.add(String
.format("%s/%s/%s", config.getBasePath(), partitionPath,
FSUtils.maskWithoutLogVersion(fileCommitTime, afile.getFileId(),
HoodieLogFile.DELTA_EXTENSION)));
}
}
}
}
}
return deletePaths;
}
/**
* Gets the latest version < commitTime. This version file could still be used by queries.
*/
private String getLatestVersionBeforeCommit(List<HoodieDataFile> fileList,
HoodieInstant commitTime) {
for (HoodieDataFile file : fileList) {
String fileCommitTime = FSUtils.getCommitTime(file.getFileName());
if (HoodieTimeline.compareTimestamps(commitTime.getTimestamp(), fileCommitTime,
HoodieTimeline.GREATER)) {
// fileList is sorted on the reverse, so the first commit we find <= commitTime is the one we want
return fileCommitTime;
}
}
// There is no version of this file which is <= commitTime
return null;
}
/**
* Performs cleaning of the partition path according to cleaning policy and returns the number
* of files cleaned.
*
* @throws IllegalArgumentException if unknown cleaning policy is provided
*/
public HoodieCleanStat clean(String partitionPath) throws IOException {
HoodieCleaningPolicy policy = config.getCleanerPolicy();
List<String> deletePaths;
Optional<HoodieInstant> earliestCommitToRetain = Optional.empty();
if (policy == HoodieCleaningPolicy.KEEP_LATEST_COMMITS) {
deletePaths = getFilesToCleanKeepingLatestCommits(partitionPath);
int commitsRetained = config.getCleanerCommitsRetained();
if (commitTimeline.countInstants() > commitsRetained) {
earliestCommitToRetain =
commitTimeline.nthInstant(commitTimeline.countInstants() - commitsRetained);
}
} else if (policy == HoodieCleaningPolicy.KEEP_LATEST_FILE_VERSIONS) {
deletePaths = getFilesToCleanKeepingLatestVersions(partitionPath);
} else {
throw new IllegalArgumentException("Unknown cleaning policy : " + policy.name());
}
// perform the actual deletes
Map<FileStatus, Boolean> deletedFiles = Maps.newHashMap();
for (String deletePath : deletePaths) {
logger.info("Working on delete path :" + deletePath);
FileStatus[] deleteVersions = fs.globStatus(new Path(deletePath));
if (deleteVersions != null) {
for (FileStatus deleteVersion : deleteVersions) {
boolean deleteResult = fs.delete(deleteVersion.getPath(), false);
deletedFiles.put(deleteVersion, deleteResult);
if (deleteResult) {
logger.info("Cleaned file at path :" + deleteVersion.getPath());
}
}
}
}
logger.info(deletePaths.size() + " patterns used to delete in partition path:" + partitionPath);
return HoodieCleanStat.newBuilder().withPolicy(policy).withDeletePathPattern(deletePaths)
.withPartitionPath(partitionPath).withEarliestCommitRetained(earliestCommitToRetain)
.withDeletedFileResults(deletedFiles).build();
}
}