/**
* 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.wal;
import java.io.FileNotFoundException;
import java.io.IOException;
import java.io.PrintStream;
import java.util.ArrayList;
import java.util.Date;
import java.util.HashMap;
import java.util.List;
import java.util.Map;
import org.apache.commons.cli.CommandLine;
import org.apache.commons.cli.CommandLineParser;
import org.apache.commons.cli.HelpFormatter;
import org.apache.commons.cli.Options;
import org.apache.commons.cli.ParseException;
import org.apache.commons.cli.PosixParser;
import org.apache.hadoop.classification.InterfaceAudience;
import org.apache.hadoop.classification.InterfaceStability;
import org.apache.hadoop.conf.Configuration;
import org.apache.hadoop.fs.FileSystem;
import org.apache.hadoop.fs.Path;
import org.apache.hadoop.hbase.HBaseConfiguration;
import org.apache.hadoop.hbase.KeyValue;
import org.apache.hadoop.hbase.regionserver.wal.HLog.Reader;
import org.apache.hadoop.hbase.util.Bytes;
import org.codehaus.jackson.map.ObjectMapper;
/**
* HLogPrettyPrinter prints the contents of a given HLog with a variety of
* options affecting formatting and extent of content.
*
* It targets two usage cases: pretty printing for ease of debugging directly by
* humans, and JSON output for consumption by monitoring and/or maintenance
* scripts.
*
* It can filter by row, region, or sequence id.
*
* It can also toggle output of values.
*
*/
@InterfaceAudience.Public
@InterfaceStability.Evolving
public class HLogPrettyPrinter {
private boolean outputValues;
private boolean outputJSON;
// The following enable filtering by sequence, region, and row, respectively
private long sequence;
private String region;
private String row;
// enable in order to output a single list of transactions from several files
private boolean persistentOutput;
private boolean firstTxn;
// useful for programatic capture of JSON output
private PrintStream out;
// for JSON encoding
private ObjectMapper mapper;
/**
* Basic constructor that simply initializes values to reasonable defaults.
*/
public HLogPrettyPrinter() {
outputValues = false;
outputJSON = false;
sequence = -1;
region = null;
row = null;
persistentOutput = false;
firstTxn = true;
out = System.out;
mapper = new ObjectMapper();
}
/**
* Fully specified constructor.
*
* @param outputValues
* when true, enables output of values along with other log
* information
* @param outputJSON
* when true, enables output in JSON format rather than a
* "pretty string"
* @param sequence
* when nonnegative, serves as a filter; only log entries with this
* sequence id will be printed
* @param region
* when not null, serves as a filter; only log entries from this
* region will be printed
* @param row
* when not null, serves as a filter; only log entries from this row
* will be printed
* @param persistentOutput
* keeps a single list running for multiple files. if enabled, the
* endPersistentOutput() method must be used!
* @param out
* Specifies an alternative to stdout for the destination of this
* PrettyPrinter's output.
*/
public HLogPrettyPrinter(boolean outputValues, boolean outputJSON,
long sequence, String region, String row, boolean persistentOutput,
PrintStream out) {
this.outputValues = outputValues;
this.outputJSON = outputJSON;
this.sequence = sequence;
this.region = region;
this.row = row;
this.persistentOutput = persistentOutput;
if (persistentOutput) {
beginPersistentOutput();
}
this.out = out;
this.firstTxn = true;
}
/**
* turns value output on
*/
public void enableValues() {
outputValues = true;
}
/**
* turns value output off
*/
public void disableValues() {
outputValues = false;
}
/**
* turns JSON output on
*/
public void enableJSON() {
outputJSON = true;
}
/**
* turns JSON output off, and turns on "pretty strings" for human consumption
*/
public void disableJSON() {
outputJSON = false;
}
/**
* sets the region by which output will be filtered
*
* @param sequence
* when nonnegative, serves as a filter; only log entries with this
* sequence id will be printed
*/
public void setSequenceFilter(long sequence) {
this.sequence = sequence;
}
/**
* sets the region by which output will be filtered
*
* @param region
* when not null, serves as a filter; only log entries from this
* region will be printed
*/
public void setRegionFilter(String region) {
this.region = region;
}
/**
* sets the region by which output will be filtered
*
* @param row
* when not null, serves as a filter; only log entries from this row
* will be printed
*/
public void setRowFilter(String row) {
this.row = row;
}
/**
* enables output as a single, persistent list. at present, only relevant in
* the case of JSON output.
*/
public void beginPersistentOutput() {
if (persistentOutput)
return;
persistentOutput = true;
firstTxn = true;
if (outputJSON)
out.print("[");
}
/**
* ends output of a single, persistent list. at present, only relevant in the
* case of JSON output.
*/
public void endPersistentOutput() {
if (!persistentOutput)
return;
persistentOutput = false;
if (outputJSON)
out.print("]");
}
/**
* reads a log file and outputs its contents, one transaction at a time, as
* specified by the currently configured options
*
* @param conf
* the HBase configuration relevant to this log file
* @param p
* the path of the log file to be read
* @throws IOException
* may be unable to access the configured filesystem or requested
* file.
*/
public void processFile(final Configuration conf, final Path p)
throws IOException {
FileSystem fs = FileSystem.get(conf);
if (!fs.exists(p)) {
throw new FileNotFoundException(p.toString());
}
if (!fs.isFile(p)) {
throw new IOException(p + " is not a file");
}
if (outputJSON && !persistentOutput) {
out.print("[");
firstTxn = true;
}
Reader log = HLogFactory.createReader(fs, p, conf);
try {
FSHLog.Entry entry;
while ((entry = log.next()) != null) {
HLogKey key = entry.getKey();
WALEdit edit = entry.getEdit();
// begin building a transaction structure
Map<String, Object> txn = key.toStringMap();
long writeTime = key.getWriteTime();
// check output filters
if (sequence >= 0 && ((Long) txn.get("sequence")) != sequence)
continue;
if (region != null && !((String) txn.get("region")).equals(region))
continue;
// initialize list into which we will store atomic actions
List<Map> actions = new ArrayList<Map>();
for (KeyValue kv : edit.getKeyValues()) {
// add atomic operation to txn
Map<String, Object> op =
new HashMap<String, Object>(kv.toStringMap());
if (outputValues)
op.put("value", Bytes.toStringBinary(kv.getValue()));
// check row output filter
if (row == null || ((String) op.get("row")).equals(row))
actions.add(op);
}
if (actions.size() == 0)
continue;
txn.put("actions", actions);
if (outputJSON) {
// JSON output is a straightforward "toString" on the txn object
if (firstTxn)
firstTxn = false;
else
out.print(",");
// encode and print JSON
out.print(mapper.writeValueAsString(txn));
} else {
// Pretty output, complete with indentation by atomic action
out.println("Sequence " + txn.get("sequence") + " "
+ "from region " + txn.get("region") + " " + "in table "
+ txn.get("table") + " at write timestamp: " + new Date(writeTime));
for (int i = 0; i < actions.size(); i++) {
Map op = actions.get(i);
out.println(" Action:");
out.println(" row: " + op.get("row"));
out.println(" column: " + op.get("family") + ":"
+ op.get("qualifier"));
out.println(" timestamp: "
+ (new Date((Long) op.get("timestamp"))));
if (outputValues)
out.println(" value: " + op.get("value"));
}
}
}
} finally {
log.close();
}
if (outputJSON && !persistentOutput) {
out.print("]");
}
}
public static void main(String[] args) throws IOException {
run(args);
}
/**
* Pass one or more log file names and formatting options and it will dump out
* a text version of the contents on <code>stdout</code>.
*
* @param args
* Command line arguments
* @throws IOException
* Thrown upon file system errors etc.
* @throws ParseException
* Thrown if command-line parsing fails.
*/
public static void run(String[] args) throws IOException {
// create options
Options options = new Options();
options.addOption("h", "help", false, "Output help message");
options.addOption("j", "json", false, "Output JSON");
options.addOption("p", "printvals", false, "Print values");
options.addOption("r", "region", true,
"Region to filter by. Pass region name; e.g. '.META.,,1'");
options.addOption("s", "sequence", true,
"Sequence to filter by. Pass sequence number.");
options.addOption("w", "row", true, "Row to filter by. Pass row name.");
HLogPrettyPrinter printer = new HLogPrettyPrinter();
CommandLineParser parser = new PosixParser();
List files = null;
try {
CommandLine cmd = parser.parse(options, args);
files = cmd.getArgList();
if (files.size() == 0 || cmd.hasOption("h")) {
HelpFormatter formatter = new HelpFormatter();
formatter.printHelp("HLog <filename...>", options, true);
System.exit(-1);
}
// configure the pretty printer using command line options
if (cmd.hasOption("p"))
printer.enableValues();
if (cmd.hasOption("j"))
printer.enableJSON();
if (cmd.hasOption("r"))
printer.setRegionFilter(cmd.getOptionValue("r"));
if (cmd.hasOption("s"))
printer.setSequenceFilter(Long.parseLong(cmd.getOptionValue("s")));
if (cmd.hasOption("w"))
printer.setRowFilter(cmd.getOptionValue("w"));
} catch (ParseException e) {
e.printStackTrace();
HelpFormatter formatter = new HelpFormatter();
formatter.printHelp("HFile filename(s) ", options, true);
System.exit(-1);
}
// get configuration, file system, and process the given files
Configuration conf = HBaseConfiguration.create();
conf.set("fs.defaultFS",
conf.get(org.apache.hadoop.hbase.HConstants.HBASE_DIR));
conf.set("fs.default.name",
conf.get(org.apache.hadoop.hbase.HConstants.HBASE_DIR));
// begin output
printer.beginPersistentOutput();
for (Object f : files) {
Path file = new Path((String) f);
FileSystem fs = file.getFileSystem(conf);
if (!fs.exists(file)) {
System.err.println("ERROR, file doesnt exist: " + file);
return;
}
printer.processFile(conf, file);
}
printer.endPersistentOutput();
}
}