/**
*
* 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.mob.mapreduce;
import java.io.IOException;
import java.util.Arrays;
import java.util.Base64;
import java.util.HashSet;
import java.util.Set;
import java.util.UUID;
import org.apache.hadoop.conf.Configuration;
import org.apache.hadoop.conf.Configured;
import org.apache.hadoop.fs.FileStatus;
import org.apache.hadoop.fs.FileSystem;
import org.apache.hadoop.fs.Path;
import org.apache.hadoop.hbase.Cell;
import org.apache.hadoop.hbase.HBaseConfiguration;
import org.apache.hadoop.hbase.HConstants;
import org.apache.hadoop.hbase.TableName;
import org.apache.hadoop.hbase.client.Admin;
import org.apache.hadoop.hbase.client.ColumnFamilyDescriptor;
import org.apache.hadoop.hbase.client.Connection;
import org.apache.hadoop.hbase.client.ConnectionFactory;
import org.apache.hadoop.hbase.client.Result;
import org.apache.hadoop.hbase.client.Scan;
import org.apache.hadoop.hbase.client.TableDescriptor;
import org.apache.hadoop.hbase.io.HFileLink;
import org.apache.hadoop.hbase.io.ImmutableBytesWritable;
import org.apache.hadoop.hbase.mapreduce.TableInputFormat;
import org.apache.hadoop.hbase.mapreduce.TableMapReduceUtil;
import org.apache.hadoop.hbase.mapreduce.TableMapper;
import org.apache.hadoop.hbase.mob.MobConstants;
import org.apache.hadoop.hbase.mob.MobUtils;
import org.apache.hadoop.hbase.util.Bytes;
import org.apache.hadoop.hbase.util.CommonFSUtils;
import org.apache.hadoop.hbase.util.EnvironmentEdgeManager;
import org.apache.hadoop.hbase.util.HFileArchiveUtil;
import org.apache.hadoop.hbase.util.Pair;
import org.apache.hadoop.io.Text;
import org.apache.hadoop.mapreduce.Job;
import org.apache.hadoop.mapreduce.Reducer;
import org.apache.hadoop.mapreduce.lib.output.TextOutputFormat;
import org.apache.hadoop.security.UserGroupInformation;
import org.apache.hadoop.util.Tool;
import org.apache.hadoop.util.ToolRunner;
import org.apache.yetus.audience.InterfaceAudience;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
/**
* Scans a given table + CF for all mob reference cells to get the list of backing mob files.
* For each referenced file we attempt to verify that said file is on the FileSystem in a place
* that the MOB system will look when attempting to resolve the actual value.
*
* The job includes counters that can help provide a rough sketch of the mob data.
*
* <pre>
* Map-Reduce Framework
* Map input records=10000
* ...
* Reduce output records=99
* ...
* CELLS PER ROW
* Number of rows with 1s of cells per row=10000
* MOB
* NUM_CELLS=52364
* PROBLEM
* Affected rows=338
* Problem MOB files=2
* ROWS WITH PROBLEMS PER FILE
* Number of HFiles with 100s of affected rows=2
* SIZES OF CELLS
* Number of cells with size in the 10,000s of bytes=627
* Number of cells with size in the 100,000s of bytes=51392
* Number of cells with size in the 1,000,000s of bytes=345
* SIZES OF ROWS
* Number of rows with total size in the 100,000s of bytes=6838
* Number of rows with total size in the 1,000,000s of bytes=3162
* </pre>
*
* * Map-Reduce Framework:Map input records - the number of rows with mob references
* * Map-Reduce Framework:Reduce output records - the number of unique hfiles referenced
* * MOB:NUM_CELLS - the total number of mob reference cells
* * PROBLEM:Affected rows - the number of rows that reference hfiles with an issue
* * PROBLEM:Problem MOB files - the number of unique hfiles that have an issue
* * CELLS PER ROW: - this counter group gives a histogram of the order of magnitude of the
* number of cells in a given row by grouping by the number of digits used in each count.
* This allows us to see more about the distribution of cells than what we can determine
* with just the cell count and the row count. In this particular example we can see that
* all of our rows have somewhere between 1 - 9 cells.
* * ROWS WITH PROBLEMS PER FILE: - this counter group gives a histogram of the order of
* magnitude of the number of rows in each of the hfiles with a problem. e.g. in the
* example there are 2 hfiles and they each have the same order of magnitude number of rows,
* specifically between 100 and 999.
* * SIZES OF CELLS: - this counter group gives a histogram of the order of magnitude of
* the size of mob values according to our reference cells. e.g. in the example above we
* have cell sizes that are all between 10,000 bytes and 9,999,999 bytes. From this
* histogram we can also see that _most_ cells are 100,000 - 999,000 bytes and the smaller
* and bigger ones are outliers making up less than 2% of mob cells.
* * SIZES OF ROWS: - this counter group gives a histogram of the order of magnitude of the
* size of mob values across each row according to our reference cells. In the example above
* we have rows that are are between 100,000 bytes and 9,999,999 bytes. We can also see that
* about 2/3rd of our rows are 100,000 - 999,999 bytes.
*
* Generates a report that gives one file status per line, with tabs dividing fields.
*
* <pre>
* RESULT OF LOOKUP FILE REF comma seperated, base64 encoded rows when there's a problem
* </pre>
*
* e.g.
*
* <pre>
* MOB DIR 09c576e28a65ed2ead0004d192ffaa382019110184b30a1c7e034573bf8580aef8393402
* MISSING FILE 28e252d7f013973174750d483d358fa020191101f73536e7133f4cd3ab1065edf588d509 MmJiMjMyYzBiMTNjNzc0OTY1ZWY4NTU4ZjBmYmQ2MTUtNTIz,MmEzOGE0YTkzMTZjNDllNWE4MzM1MTdjNDVkMzEwNzAtODg=
* </pre>
*
* Possible results are listed; the first three indicate things are working properly.
* * MOB DIR - the reference is in the normal MOB area for the given table and CF
* * HLINK TO ARCHIVE FOR SAME TABLE - the reference is present in the archive area for this
* table and CF
* * HLINK TO ARCHIVE FOR OTHER TABLE - the reference is present in a different table and CF,
* either in the MOB or archive areas (e.g. from a snapshot restore or clone)
* * ARCHIVE WITH HLINK BUT NOT FROM OUR TABLE - the reference is currently present in the archive
* area for this table and CF, but it is kept there because a _different_ table has a
* reference to it (e.g. from a snapshot clone). If these other tables are removed then
* the file will likely be deleted unless there is a snapshot also referencing it.
* * ARCHIVE BUT NO HLINKS - the reference is currently present in the archive for this table and
* CF, but there are no references present to prevent its removal. Unless it is newer than
* the general TTL (default 5 minutes) or referenced in a snapshot it will be subject to
* cleaning.
* * ARCHIVE BUT FAILURE WHILE CHECKING HLINKS - Check the job logs to see why things failed while
* looking for why this file is being kept around.
* * MISSING FILE - We couldn't find the reference on the FileSystem. Either there is dataloss due
* to a bug in the MOB storage system or the MOB storage is damaged but in an edge case that
* allows it to work for now. You can verify which by doing a raw reference scan to get the
* referenced hfile and check the underlying filesystem. See the ref guide section on mob
* for details.
* * HLINK BUT POINT TO MISSING FILE - There is a pointer in our mob area for this table and CF
* to a file elsewhere on the FileSystem, however the file it points to no longer exists.
* * MISSING FILE BUT FAILURE WHILE CHECKING HLINKS - We could not find the referenced file,
* however you should check the job logs to see why we couldn't check to see if there is a
* pointer to the referenced file in our archive or another table's archive or mob area.
*
*/
@InterfaceAudience.Private
public class MobRefReporter extends Configured implements Tool {
private static Logger LOG = LoggerFactory.getLogger(MobRefReporter.class);
public static final String NAME = "mobrefs";
static final String REPORT_JOB_ID = "mob.report.job.id";
static final String REPORT_START_DATETIME = "mob.report.job.start";
public static class MobRefMapper extends TableMapper<Text, ImmutableBytesWritable> {
@Override
public void map(ImmutableBytesWritable r, Result columns, Context context) throws IOException,
InterruptedException {
if (columns == null) {
return;
}
Cell[] cells = columns.rawCells();
if (cells == null || cells.length == 0) {
return;
}
Set<String> files = new HashSet<>();
long count = 0;
long size = 0;
for (Cell c : cells) {
if (MobUtils.hasValidMobRefCellValue(c)) {
// TODO confirm there aren't tags
String fileName = MobUtils.getMobFileName(c);
if (!files.contains(fileName)) {
context.write(new Text(fileName), r);
files.add(fileName);
}
final int cellsize = MobUtils.getMobValueLength(c);
context.getCounter("SIZES OF CELLS", "Number of cells with size in the " +
log10GroupedString(cellsize) + "s of bytes").increment(1L);
size += cellsize;
count++;
} else {
LOG.debug("cell is not a mob ref, even though we asked for only refs. cell={}", c);
}
}
context.getCounter("CELLS PER ROW", "Number of rows with " + log10GroupedString(count) +
"s of cells per row").increment(1L);
context.getCounter("SIZES OF ROWS", "Number of rows with total size in the " +
log10GroupedString(size) + "s of bytes").increment(1L);
context.getCounter("MOB","NUM_CELLS").increment(count);
}
}
public static class MobRefReducer extends
Reducer<Text, ImmutableBytesWritable, Text, Text> {
TableName table;
String mobRegion;
Path mob;
Path archive;
String seperator;
/* Results that mean things are fine */
final Text OK_MOB_DIR = new Text("MOB DIR");
final Text OK_HLINK_RESTORE = new Text("HLINK TO ARCHIVE FOR SAME TABLE");
final Text OK_HLINK_CLONE = new Text("HLINK TO ARCHIVE FOR OTHER TABLE");
/* Results that mean something is incorrect */
final Text INCONSISTENT_ARCHIVE_BAD_LINK =
new Text("ARCHIVE WITH HLINK BUT NOT FROM OUR TABLE");
final Text INCONSISTENT_ARCHIVE_STALE = new Text("ARCHIVE BUT NO HLINKS");
final Text INCONSISTENT_ARCHIVE_IOE = new Text("ARCHIVE BUT FAILURE WHILE CHECKING HLINKS");
/* Results that mean data is probably already gone */
final Text DATALOSS_MISSING = new Text("MISSING FILE");
final Text DATALOSS_HLINK_DANGLING = new Text("HLINK BUT POINTS TO MISSING FILE");
final Text DATALOSS_MISSING_IOE = new Text("MISSING FILE BUT FAILURE WHILE CHECKING HLINKS");
final Base64.Encoder base64 = Base64.getEncoder();
@Override
public void setup(Context context) throws IOException, InterruptedException {
final Configuration conf = context.getConfiguration();
final String tableName = conf.get(TableInputFormat.INPUT_TABLE);
if (null == tableName) {
throw new IOException("Job configuration did not include table.");
}
table = TableName.valueOf(tableName);
mobRegion = MobUtils.getMobRegionInfo(table).getEncodedName();
final String family = conf.get(TableInputFormat.SCAN_COLUMN_FAMILY);
if (null == family) {
throw new IOException("Job configuration did not include column family");
}
mob = MobUtils.getMobFamilyPath(conf, table, family);
LOG.info("Using active mob area '{}'", mob);
archive = HFileArchiveUtil.getStoreArchivePath(conf, table,
MobUtils.getMobRegionInfo(table).getEncodedName(), family);
LOG.info("Using archive mob area '{}'", archive);
seperator = conf.get(TextOutputFormat.SEPERATOR, "\t");
}
@Override
public void reduce(Text key, Iterable<ImmutableBytesWritable> rows, Context context)
throws IOException, InterruptedException {
final Configuration conf = context.getConfiguration();
final String file = key.toString();
// active mob area
if (mob.getFileSystem(conf).exists(new Path(mob, file))) {
LOG.debug("Found file '{}' in mob area", file);
context.write(OK_MOB_DIR, key);
// archive area - is there an hlink back reference (from a snapshot from same table)
} else if (archive.getFileSystem(conf).exists(new Path(archive, file))) {
Path backRefDir = HFileLink.getBackReferencesDir(archive, file);
try {
FileStatus[] backRefs = CommonFSUtils.listStatus(archive.getFileSystem(conf), backRefDir);
if (backRefs != null) {
boolean found = false;
for (FileStatus backRef : backRefs) {
Pair<TableName, String> refParts = HFileLink.parseBackReferenceName(
backRef.getPath().getName());
if (table.equals(refParts.getFirst()) && mobRegion.equals(refParts.getSecond())) {
Path hlinkPath = HFileLink.getHFileFromBackReference(MobUtils.getMobHome(conf),
backRef.getPath());
if (hlinkPath.getFileSystem(conf).exists(hlinkPath)) {
found = true;
} else {
LOG.warn("Found file '{}' in archive area with a back reference to the mob area "
+ "for our table, but the mob area does not have a corresponding hfilelink.",
file);
}
}
}
if (found) {
LOG.debug("Found file '{}' in archive area. has proper hlink back references to "
+ "suggest it is from a restored snapshot for this table.", file);
context.write(OK_HLINK_RESTORE, key);
} else {
LOG.warn("Found file '{}' in archive area, but the hlink back references do not "
+ "properly point to the mob area for our table.", file);
context.write(INCONSISTENT_ARCHIVE_BAD_LINK, encodeRows(context, key, rows));
}
} else {
LOG.warn("Found file '{}' in archive area, but there are no hlinks pointing to it. Not "
+ "yet used snapshot or an error.", file);
context.write(INCONSISTENT_ARCHIVE_STALE, encodeRows(context, key, rows));
}
} catch (IOException e) {
LOG.warn("Found file '{}' in archive area, but got an error while checking "
+ "on back references.", file, e);
context.write(INCONSISTENT_ARCHIVE_IOE, encodeRows(context, key, rows));
}
} else {
// check for an hlink in the active mob area (from a snapshot of a different table)
try {
/**
* we are doing this ourselves instead of using FSUtils.getReferenceFilePaths because
* we know the mob region never splits, so we can only have HFileLink references
* and looking for just them is cheaper then listing everything.
*
* This glob should match the naming convention for HFileLinks to our referenced hfile.
* As simplified explanation those file names look like "table=region-hfile". For details
* see the {@link HFileLink#createHFileLinkName HFileLink implementation}.
*/
FileStatus[] hlinks = mob.getFileSystem(conf).globStatus(new Path(mob + "/*=*-" + file));
if (hlinks != null && hlinks.length != 0) {
if (hlinks.length != 1) {
LOG.warn("Found file '{}' as hfilelinks in the mob area, but there are more than " +
"one: {}", file, Arrays.deepToString(hlinks));
}
HFileLink found = null;
for (FileStatus hlink : hlinks) {
HFileLink tmp = HFileLink.buildFromHFileLinkPattern(conf, hlink.getPath());
if (tmp.exists(archive.getFileSystem(conf))) {
found = tmp;
break;
} else {
LOG.debug("Target file does not exist for ref {}", tmp);
}
}
if (found != null) {
LOG.debug("Found file '{}' as a ref in the mob area: {}", file, found);
context.write(OK_HLINK_CLONE, key);
} else {
LOG.warn("Found file '{}' as ref(s) in the mob area but they do not point to an hfile"
+ " that exists.", file);
context.write(DATALOSS_HLINK_DANGLING, encodeRows(context, key, rows));
}
} else {
LOG.error("Could not find referenced file '{}'. See the docs on this tool.", file);
LOG.debug("Note that we don't have the server-side tag from the mob cells that says "
+ "what table the reference is originally from. So if the HFileLink in this table "
+ "is missing but the referenced file is still in the table from that tag, then "
+ "lookups of these impacted rows will work. Do a scan of the reference details "
+ "of the cell for the hfile name and then check the entire hbase install if this "
+ "table was made from a snapshot of another table. see the ref guide section on "
+ "mob for details.");
context.write(DATALOSS_MISSING, encodeRows(context, key, rows));
}
} catch (IOException e) {
LOG.error(
"Exception while checking mob area of our table for HFileLinks that point to {}",
file, e);
context.write(DATALOSS_MISSING_IOE, encodeRows(context, key, rows));
}
}
}
/**
* reuses the passed Text key. appends the configured seperator and then a comma seperated list
* of base64 encoded row keys
*/
private Text encodeRows(Context context, Text key, Iterable<ImmutableBytesWritable> rows)
throws IOException {
StringBuilder sb = new StringBuilder(key.toString());
sb.append(seperator);
boolean moreThanOne = false;
long count = 0;
for (ImmutableBytesWritable row : rows) {
if (moreThanOne) {
sb.append(",");
}
sb.append(base64.encodeToString(row.copyBytes()));
moreThanOne = true;
count++;
}
context.getCounter("PROBLEM", "Problem MOB files").increment(1L);
context.getCounter("PROBLEM", "Affected rows").increment(count);
context.getCounter("ROWS WITH PROBLEMS PER FILE", "Number of HFiles with " +
log10GroupedString(count) + "s of affected rows").increment(1L);
key.set(sb.toString());
return key;
}
}
/**
* Returns the string representation of the given number after grouping it
* into log10 buckets. e.g. 0-9 -> 1, 10-99 -> 10, ..., 100,000-999,999 -> 100,000, etc.
*/
static String log10GroupedString(long number) {
return String.format("%,d", (long)(Math.pow(10d, Math.floor(Math.log10(number)))));
}
/**
* Main method for the tool.
* @return 0 if success, 1 for bad args. 2 if job aborted with an exception,
* 3 if mr job was unsuccessful
*/
public int run(String[] args) throws IOException, InterruptedException {
// TODO make family and table optional
if (args.length != 3) {
printUsage();
return 1;
}
final String output = args[0];
final String tableName = args[1];
final String familyName = args[2];
final long reportStartTime = EnvironmentEdgeManager.currentTime();
Configuration conf = getConf();
try {
FileSystem fs = FileSystem.get(conf);
// check whether the current user is the same one with the owner of hbase root
String currentUserName = UserGroupInformation.getCurrentUser().getShortUserName();
FileStatus[] hbaseRootFileStat = fs.listStatus(new Path(conf.get(HConstants.HBASE_DIR)));
if (hbaseRootFileStat.length > 0) {
String owner = hbaseRootFileStat[0].getOwner();
if (!owner.equals(currentUserName)) {
String errorMsg = "The current user[" + currentUserName
+ "] does not have hbase root credentials."
+ " If this job fails due to an inability to read HBase's internal directories, "
+ "you will need to rerun as a user with sufficient permissions. The HBase superuser "
+ "is a safe choice.";
LOG.warn(errorMsg);
}
} else {
LOG.error("The passed configs point to an HBase dir does not exist: {}",
conf.get(HConstants.HBASE_DIR));
throw new IOException("The target HBase does not exist");
}
byte[] family;
int maxVersions;
TableName tn = TableName.valueOf(tableName);
try (Connection connection = ConnectionFactory.createConnection(conf);
Admin admin = connection.getAdmin()) {
TableDescriptor htd = admin.getDescriptor(tn);
ColumnFamilyDescriptor hcd = htd.getColumnFamily(Bytes.toBytes(familyName));
if (hcd == null || !hcd.isMobEnabled()) {
throw new IOException("Column family " + familyName + " is not a MOB column family");
}
family = hcd.getName();
maxVersions = hcd.getMaxVersions();
}
String id = getClass().getSimpleName() + UUID.randomUUID().toString().replace("-", "");
Job job = null;
Scan scan = new Scan();
scan.addFamily(family);
// Do not retrieve the mob data when scanning
scan.setAttribute(MobConstants.MOB_SCAN_RAW, Bytes.toBytes(Boolean.TRUE));
scan.setAttribute(MobConstants.MOB_SCAN_REF_ONLY, Bytes.toBytes(Boolean.TRUE));
// If a scanner caching value isn't set, pick a smaller default since we know we're doing
// a full table scan and don't want to impact other clients badly.
scan.setCaching(conf.getInt(HConstants.HBASE_CLIENT_SCANNER_CACHING, 10000));
scan.setCacheBlocks(false);
scan.readVersions(maxVersions);
conf.set(REPORT_JOB_ID, id);
job = Job.getInstance(conf);
job.setJarByClass(getClass());
TableMapReduceUtil.initTableMapperJob(tn, scan,
MobRefMapper.class, Text.class, ImmutableBytesWritable.class, job);
job.setReducerClass(MobRefReducer.class);
job.setOutputFormatClass(TextOutputFormat.class);
TextOutputFormat.setOutputPath(job, new Path(output));
job.setJobName(getClass().getSimpleName() + "-" + tn + "-" + familyName);
// for use in the reducer. easier than re-parsing it out of the scan string.
job.getConfiguration().set(TableInputFormat.SCAN_COLUMN_FAMILY, familyName);
// Use when we start this job as the base point for file "recency".
job.getConfiguration().setLong(REPORT_START_DATETIME, reportStartTime);
if (job.waitForCompletion(true)) {
LOG.info("Finished creating report for '{}', family='{}'", tn, familyName);
} else {
System.err.println("Job was not successful");
return 3;
}
return 0;
} catch (ClassNotFoundException | RuntimeException | IOException | InterruptedException e) {
System.err.println("Job aborted due to exception " + e);
return 2; // job failed
}
}
public static void main(String[] args) throws Exception {
Configuration conf = HBaseConfiguration.create();
int ret = ToolRunner.run(conf, new MobRefReporter(), args);
System.exit(ret);
}
private void printUsage() {
System.err.println("Usage:\n" + "--------------------------\n" + MobRefReporter.class.getName()
+ " output-dir tableName familyName");
System.err.println(" output-dir Where to write output report.");
System.err.println(" tableName The table name");
System.err.println(" familyName The column family name");
}
}
