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HBaseClient.java
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HBaseClient.java
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/**
* Copyright (c) 2010 Yahoo! Inc. All rights reserved.
*
* 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. See accompanying
* LICENSE file.
*/
package com.yahoo.ycsb.db;
import com.yahoo.ycsb.DBException;
import java.io.IOException;
import java.util.*;
//import java.util.HashMap;
//import java.util.Properties;
//import java.util.Set;
//import java.util.Vector;
import org.apache.hadoop.hbase.client.HTable;
//import org.apache.hadoop.hbase.client.Scanner;
import org.apache.hadoop.hbase.client.Get;
import org.apache.hadoop.hbase.client.Put;
import org.apache.hadoop.hbase.client.Delete;
import org.apache.hadoop.hbase.client.Scan;
import org.apache.hadoop.hbase.client.Result;
import org.apache.hadoop.hbase.client.ResultScanner;
//import org.apache.hadoop.hbase.io.Cell;
//import org.apache.hadoop.hbase.io.RowResult;
import org.apache.hadoop.hbase.util.Bytes;
import org.apache.hadoop.hbase.HBaseConfiguration;
public class HBaseClient extends com.yahoo.ycsb.DB
{
public boolean _debug=false;
public String _table="";
public HTable _hTable=null;
public String _columnFamily="";
public static final int Ok=0;
public static final int ServerError=-1;
public static final int HttpError=-2;
public static final int NoMatchingRecord=-3;
public static Object tableLock = new Object();
/**
* Initialize any state for this DB.
* Called once per DB instance; there is one DB instance per client thread.
*/
public void init() throws DBException
{
if ( (getProperties().getProperty("debug")!=null) &&
(getProperties().getProperty("debug").compareTo("true")==0) )
{
_debug=true;
}
_columnFamily = getProperties().getProperty("columnfamily");
if (_columnFamily == null)
{
System.err.println("Error, must specify a columnfamily for HBase table");
throw new DBException("No columnfamily specified");
}
}
/**
* Cleanup any state for this DB.
* Called once per DB instance; there is one DB instance per client thread.
*/
public void cleanup() throws DBException
{
}
public void getHTable(String table) throws IOException
{
synchronized (tableLock) {
HBaseConfiguration config = new HBaseConfiguration();
_hTable = new HTable(config, table);
//2 suggestions from http://ryantwopointoh.blogspot.com/2009/01/performance-of-hbase-importing.html
_hTable.setAutoFlush(false);
_hTable.setWriteBufferSize(1024*1024*12);
//return hTable;
}
}
/**
* Read a record from the database. Each field/value pair from the result will be stored in a HashMap.
*
* @param table The name of the table
* @param key The record key of the record to read.
* @param fields The list of fields to read, or null for all of them
* @param result A HashMap of field/value pairs for the result
* @return Zero on success, a non-zero error code on error
*/
public int read(String table, String key, Set<String> fields, HashMap<String,String> result)
{
//if this is a "new" table, init HTable object. Else, use existing one
if (!_table.equals(table)) {
_hTable = null;
try
{
getHTable(table);
_table = table;
}
catch (IOException e)
{
System.err.println("Error accessing HBase table: "+e);
return ServerError;
}
}
Result r = null;
try
{
if (_debug) {
System.out.println("Doing read from HBase columnfamily "+_columnFamily);
System.out.println("Doing read for key: "+key);
}
Get g = new Get(Bytes.toBytes(key));
r = _hTable.get(g);
}
catch (IOException e)
{
System.err.println("Error doing get: "+e);
return ServerError;
}
catch (ConcurrentModificationException e)
{
//do nothing for now...need to understand HBase concurrency model better
return ServerError;
}
//now parse out all desired fields
if (fields != null) {
for (String field : fields) {
byte[] value = r.getValue(Bytes.toBytes(_columnFamily),Bytes.toBytes(field));
result.put(field,Bytes.toString(value));
if (_debug) {
System.out.println("Result for field: "+field+" is: "+Bytes.toString(value));
}
}
}
return Ok;
}
/**
* Perform a range scan for a set of records in the database. Each field/value pair from the result will be stored in a HashMap.
*
* @param table The name of the table
* @param startkey The record key of the first record to read.
* @param recordcount The number of records to read
* @param fields The list of fields to read, or null for all of them
* @param result A Vector of HashMaps, where each HashMap is a set field/value pairs for one record
* @return Zero on success, a non-zero error code on error
*/
public int scan(String table, String startkey, int recordcount, Set<String> fields, Vector<HashMap<String,String>> result)
{
//if this is a "new" table, init HTable object. Else, use existing one
if (!_table.equals(table)) {
_hTable = null;
try
{
getHTable(table);
_table = table;
}
catch (IOException e)
{
System.err.println("Error accessing HBase table: "+e);
return ServerError;
}
}
Scan s = new Scan(Bytes.toBytes(startkey));
//HBase has no record limit. Here, assume recordcount is small enough to bring back in one call.
//We get back recordcount records
s.setCaching(recordcount);
//add specified fields or else all fields
if (fields == null)
{
s.addFamily(Bytes.toBytes(_columnFamily));
}
else
{
for (String field : fields)
{
s.addColumn(Bytes.toBytes(_columnFamily),Bytes.toBytes(field));
}
}
//get results
ResultScanner scanner = null;
try {
scanner = _hTable.getScanner(s);
int numResults = 0;
for (Result rr = scanner.next(); rr != null; rr = scanner.next())
{
//get row key
String key = Bytes.toString(rr.getRow());
if (_debug)
{
System.out.println("Got scan result for key: "+key);
}
HashMap<String,String> rowResult = new HashMap<String, String>();
//parse row
if (fields != null) //parse specified field list
{
for (String field : fields) {
byte[] value = rr.getValue(Bytes.toBytes(_columnFamily),Bytes.toBytes(field));
rowResult.put(field,Bytes.toString(value));
if (_debug)
{
System.out.println("Result for field: "+field+" is: "+Bytes.toString(value));
}
}
}
else //get all fields
{
//HBase can return a mapping for all columns in a column family
NavigableMap<byte[], byte[]> scanMap = rr.getFamilyMap(Bytes.toBytes(_columnFamily));
for (byte[] fieldkey : scanMap.keySet())
{
String value = Bytes.toString(scanMap.get(fieldkey));
rowResult.put(Bytes.toString(fieldkey),value);
if (_debug)
{
System.out.println("Result for field: "+Bytes.toString(fieldkey)+" is: "+value);
}
}
}
//add rowResult to result vector
result.add(rowResult);
numResults++;
if (numResults >= recordcount) //if hit recordcount, bail out
{
break;
}
} //done with row
}
catch (IOException e) {
if (_debug)
{
System.out.println("Error in getting/parsing scan result: "+e);
}
return ServerError;
}
finally {
scanner.close();
}
return Ok;
}
/**
* Update a record in the database. Any field/value pairs in the specified values HashMap will be written into the record with the specified
* record key, overwriting any existing values with the same field name.
*
* @param table The name of the table
* @param key The record key of the record to write
* @param values A HashMap of field/value pairs to update in the record
* @return Zero on success, a non-zero error code on error
*/
public int update(String table, String key, HashMap<String,String> values)
{
//if this is a "new" table, init HTable object. Else, use existing one
if (!_table.equals(table)) {
_hTable = null;
try
{
getHTable(table);
_table = table;
}
catch (IOException e)
{
System.err.println("Error accessing HBase table: "+e);
return ServerError;
}
}
if (_debug) {
System.out.println("Setting up put for key: "+key);
}
Put p = new Put(Bytes.toBytes(key));
for (String fieldkey : values.keySet())
{
String value = values.get(fieldkey);
if (_debug) {
System.out.println("Adding field/value " + fieldkey + "/"+value+" to put request");
}
p.add(Bytes.toBytes(_columnFamily),Bytes.toBytes(fieldkey),Bytes.toBytes(value));
}
try
{
_hTable.put(p);
}
catch (IOException e)
{
if (_debug) {
System.err.println("Error doing put: "+e);
}
return ServerError;
}
catch (ConcurrentModificationException e)
{
//do nothing for now...hope this is rare
return ServerError;
}
return Ok;
}
/**
* Insert a record in the database. Any field/value pairs in the specified values HashMap will be written into the record with the specified
* record key.
*
* @param table The name of the table
* @param key The record key of the record to insert.
* @param values A HashMap of field/value pairs to insert in the record
* @return Zero on success, a non-zero error code on error
*/
public int insert(String table, String key, HashMap<String,String> values)
{
return update(table,key,values);
}
/**
* Delete a record from the database.
*
* @param table The name of the table
* @param key The record key of the record to delete.
* @return Zero on success, a non-zero error code on error
*/
public int delete(String table, String key)
{
//if this is a "new" table, init HTable object. Else, use existing one
if (!_table.equals(table)) {
_hTable = null;
try
{
getHTable(table);
_table = table;
}
catch (IOException e)
{
System.err.println("Error accessing HBase table: "+e);
return ServerError;
}
}
if (_debug) {
System.out.println("Doing delete for key: "+key);
}
Delete d = new Delete(Bytes.toBytes(key));
try
{
_hTable.delete(d);
}
catch (IOException e)
{
if (_debug) {
System.err.println("Error doing delete: "+e);
}
return ServerError;
}
return Ok;
}
public static void main(String[] args)
{
if (args.length!=3)
{
System.out.println("Please specify a threadcount, columnfamily and operation count");
System.exit(0);
}
final int keyspace=10000; //120000000;
final int threadcount=Integer.parseInt(args[0]);
final String columnfamily=args[1];
final int opcount=Integer.parseInt(args[2])/threadcount;
Vector<Thread> allthreads=new Vector<Thread>();
for (int i=0; i<threadcount; i++)
{
Thread t=new Thread()
{
public void run()
{
try
{
Random random=new Random();
HBaseClient cli=new HBaseClient();
Properties props=new Properties();
props.setProperty("columnfamily",columnfamily);
props.setProperty("debug","true");
cli.setProperties(props);
cli.init();
//HashMap<String,String> result=new HashMap<String,String>();
long accum=0;
for (int i=0; i<opcount; i++)
{
int keynum=random.nextInt(keyspace);
String key="user"+keynum;
long st=System.currentTimeMillis();
int rescode;
/*
HashMap hm = new HashMap();
hm.put("field1","value1");
hm.put("field2","value2");
hm.put("field3","value3");
rescode=cli.insert("table1",key,hm);
HashSet<String> s = new HashSet();
s.add("field1");
s.add("field2");
rescode=cli.read("table1", key, s, result);
//rescode=cli.delete("table1",key);
rescode=cli.read("table1", key, s, result);
*/
HashSet<String> scanFields = new HashSet<String>();
scanFields.add("field1");
scanFields.add("field3");
Vector<HashMap<String,String>> scanResults = new Vector<HashMap<String,String>>();
rescode = cli.scan("table1","user2",20,null,scanResults);
long en=System.currentTimeMillis();
accum+=(en-st);
if (rescode!=Ok)
{
System.out.println("Error "+rescode+" for "+key);
}
if (i%1==0)
{
System.out.println(i+" operations, average latency: "+(((double)accum)/((double)i)));
}
}
//System.out.println("Average latency: "+(((double)accum)/((double)opcount)));
//System.out.println("Average get latency: "+(((double)cli.TotalGetTime)/((double)cli.TotalGetOps)));
}
catch (Exception e)
{
e.printStackTrace();
}
}
};
allthreads.add(t);
}
long st=System.currentTimeMillis();
for (Thread t: allthreads)
{
t.start();
}
for (Thread t: allthreads)
{
try
{
t.join();
}
catch (InterruptedException e)
{
}
}
long en=System.currentTimeMillis();
System.out.println("Throughput: "+((1000.0)*(((double)(opcount*threadcount))/((double)(en-st))))+" ops/sec");
}
}
/* For customized vim control
* set autoindent
* set si
* set shiftwidth=4
*/

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