mapreducer编程模型是一种八股文的代码逻辑,就以用户行为分析求流存率的作为例子

1.map端来说:必须继承hadoop规定好的mapper类:在读取hbase数据时,已经有现成的接口
TableMapper,只需要规定输出的key和value的类型
public class LoseUserMapper extends TableMapper<KeyStatsDimension, Text> {
//////////省去代码 在执行map方法前会执行setup方法,在流失率的时候 比如说求的是七天的流失率:
1。先将七天前的那天的组合key+uuid存入一个map集合,这过程在setup方法中进行
2.再将今天的数据根据key+uuid2组成字符串
3。if(map.get(key+uuid2)!=null)
4.context.write(userDimensionKey, uuidText);发给reducer
    @Override
protected void setup(Context context) throws IOException, InterruptedException {
Configuration conf = context.getConfiguration();
long endDate = TimeUtil.parseString2Long(conf.get(GlobalConstants.END_DATE), TimeUtil.DATE_FORMAT);
long beginDate = TimeUtil.parseString2Long(conf.get(GlobalConstants.BEGIN_DATE), TimeUtil.DATE_FORMAT);
dateKey = DateDimensionKey.buildDate(endDate, DateEnum.DAY); if ((endDate - beginDate) == 7 * GlobalConstants.DAY_OF_MILLISECONDS) {
channelKpiKey = new KpiDimensionKey(KpiEnum.CHANNEL_SEVEN_DAY_LOSE.name);
versionKpiKey = new KpiDimensionKey(KpiEnum.VERSION_SEVEN_DAY_LOSE.name);
areaKpiKey = new KpiDimensionKey(KpiEnum.AREA_SEVEN_DAY_LOSE.name);
} if ((endDate - beginDate) == 14 * GlobalConstants.DAY_OF_MILLISECONDS) {
channelKpiKey = new KpiDimensionKey(KpiEnum.CHANNEL_FOURTEEN_DAY_LOSE.name);
versionKpiKey = new KpiDimensionKey(KpiEnum.VERSION_FOURTEEN_DAY_LOSE.name);
areaKpiKey = new KpiDimensionKey(KpiEnum.AREA_FOURTEEN_DAY_LOSE.name);
} if ((endDate - beginDate) /30 == GlobalConstants.DAY_OF_MILLISECONDS) {
channelKpiKey = new KpiDimensionKey(KpiEnum.CHANNEL_THIRTY_DAY_LOSE.name);
versionKpiKey = new KpiDimensionKey(KpiEnum.VERSION_THIRTY_DAY_LOSE.name);
areaKpiKey = new KpiDimensionKey(KpiEnum.AREA_THIRTY_DAY_LOSE.name);
} setActiveUserCache(conf);
} @Override
protected void map(ImmutableBytesWritable key, Result value, Context context)
throws IOException, InterruptedException {
String uuid = Bytes.toString(value.getValue(family, Bytes.toBytes(EventLogConstants.LOG_COLUMN_NAME_UUID)));
String appId = Bytes.toString(value.getValue(family, Bytes.toBytes(EventLogConstants.LOG_COLUMN_NAME_APP)));
String platformId = Bytes.toString(value.getValue(family, Bytes.toBytes(EventLogConstants.LOG_COLUMN_NAME_PLATFORM)));
String channel = Bytes.toString(value.getValue(family, Bytes.toBytes(EventLogConstants.LOG_COLUMN_NAME_CHANNEL)));
String version = Bytes.toString(value.getValue(family, Bytes.toBytes(EventLogConstants.LOG_COLUMN_NAME_VERSION)));
String country = Bytes.toString(value.getValue(family, Bytes.toBytes(EventLogConstants.LOG_COLUMN_NAME_COUNTRY)));
String province = Bytes.toString(value.getValue(family, Bytes.toBytes(EventLogConstants.LOG_COLUMN_NAME_PROVINCE)));
String city = Bytes.toString(value.getValue(family, Bytes.toBytes(EventLogConstants.LOG_COLUMN_NAME_CITY)));
String isp = Bytes.toString(value.getValue(family, Bytes.toBytes(EventLogConstants.LOG_COLUMN_NAME_ISP))); List<StatsUserDimensionKey> userDimensionKeys = getDimensionKeys(appId, platformId, channel, version, country, province, city, isp); for (StatsUserDimensionKey userDimensionKey : userDimensionKeys) {
if (activeUserCache.get(userDimensionKey.toString() + GlobalConstants.KEY_SEPARATOR + uuid) != null) {
this.uuidText.set(uuid);
context.write(userDimensionKey, uuidText);
}
}
} public void setActiveUserCache(Configuration conf){
String date = conf.get(GlobalConstants.BEGIN_DATE).replaceAll("-", ""); FilterList filterList = new FilterList();
filterList.addFilter(
new SingleColumnValueFilter(EventLogConstants.EVENT_LOGS_FAMILY_NAME_BYTES,
Bytes.toBytes(EventLogConstants.LOG_COLUMN_NAME_EVENT_NAME),
CompareFilter.CompareOp.EQUAL, Bytes.toBytes(EventLogConstants.EventEnum.START.alias)));
String[] columns = new String[] {
EventLogConstants.LOG_COLUMN_NAME_EVENT_NAME,
EventLogConstants.LOG_COLUMN_NAME_APP,
EventLogConstants.LOG_COLUMN_NAME_PLATFORM,
EventLogConstants.LOG_COLUMN_NAME_CHANNEL,
EventLogConstants.LOG_COLUMN_NAME_VERSION,
EventLogConstants.LOG_COLUMN_NAME_PROVINCE,
EventLogConstants.LOG_COLUMN_NAME_ISP,
EventLogConstants.LOG_COLUMN_NAME_UUID,
};
filterList.addFilter(this.getColumnFilter(columns)); Connection conn = null;
Admin admin = null;
Scan scan = new Scan();
Table table = null;
try {
conn = ConnectionFactory.createConnection(conf);
admin = conn.getAdmin();
String tableName = EventLogConstants.HBASE_NAME_EVENT_LOGS +"_"+ date;
table = conn.getTable(TableName.valueOf(tableName));
scan.setFilter(filterList);
ResultScanner rs = table.getScanner(scan);
for (Result r : rs) {
String appId = Bytes.toString(r.getValue(family, Bytes.toBytes(EventLogConstants.LOG_COLUMN_NAME_APP)));
String platformId = Bytes.toString(r.getValue(family, Bytes.toBytes(EventLogConstants.LOG_COLUMN_NAME_PLATFORM)));
String channel = Bytes.toString(r.getValue(family, Bytes.toBytes(EventLogConstants.LOG_COLUMN_NAME_CHANNEL)));
String version = Bytes.toString(r.getValue(family, Bytes.toBytes(EventLogConstants.LOG_COLUMN_NAME_VERSION)));
String country = Bytes.toString(r.getValue(family, Bytes.toBytes(EventLogConstants.LOG_COLUMN_NAME_COUNTRY)));
String province = Bytes.toString(r.getValue(family, Bytes.toBytes(EventLogConstants.LOG_COLUMN_NAME_PROVINCE)));
String city = Bytes.toString(r.getValue(family, Bytes.toBytes(EventLogConstants.LOG_COLUMN_NAME_CITY)));
String isp = Bytes.toString(r.getValue(family, Bytes.toBytes(EventLogConstants.LOG_COLUMN_NAME_ISP)));
String uuid = Bytes.toString(r.getValue(family, Bytes.toBytes(EventLogConstants.LOG_COLUMN_NAME_UUID))); List<StatsUserDimensionKey> userDimensionKeys = getDimensionKeys(appId, platformId, channel, version, country, province, city, isp); for (StatsUserDimensionKey userDimensionKey : userDimensionKeys) {
activeUserCache.put(userDimensionKey.toString() + GlobalConstants.KEY_SEPARATOR + uuid, 1);
}
}
} catch (Exception e) {
e.printStackTrace();
throw new RuntimeException("创建HBaseAdmin发生异常", e);
} finally {
if (admin != null) {
try {
admin.close();
} catch (IOException e) {
e.printStackTrace();
}
}
}
} private Filter getColumnFilter(String[] columns) {
int length = columns.length;
byte[][] filter = new byte[length][];
for (int i = 0; i < length; i++) {
filter[i] = Bytes.toBytes(columns[i]);
}
return new MultipleColumnPrefixFilter(filter);
} private List<StatsUserDimensionKey> getDimensionKeys(String appid, String platformId, String channel, String version, String country, String province, String city, String isp) {
List<StatsUserDimensionKey> keys = new ArrayList<>(); AppDimensionKey appKey = new AppDimensionKey(appid, AppEnum.valueOfAlias(appid).name);
List<PlatformDimensionKey> platformKeys = PlatformDimensionKey.buildList(platformId, PlatformEnum.valueOfAlias(platformId).name);
List<ChannelDimensionKey> channelKeys = ChannelDimensionKey.buildList(channel);
List<VersionDimensionKey> versionKeys = VersionDimensionKey.buildList(version);
List<AreaDimensionKey> areaKeys = AreaDimensionKey.buildList(country, province, city);
List<IspDimensionKey> ispKeys = IspDimensionKey.buildList(isp); for (PlatformDimensionKey platformKey : platformKeys) { //应用+终端+渠道 维度
for (ChannelDimensionKey channelKey : channelKeys) {
StatsUserDimensionKey userDimensionKey = new StatsUserDimensionKey();
StatsCommonDimensionKey commonKey = userDimensionKey.getCommonDimensionKey();
commonKey.setDateDimensionKey(dateKey);
commonKey.setAppDimensionKey(appKey);
commonKey.setPlatformDimensionKey(platformKey);
commonKey.setKpiDimensionKey(channelKpiKey);
userDimensionKey.setCommonDimensionKey(commonKey);
userDimensionKey.setChannelDimensionKey(channelKey);
keys.add(userDimensionKey);
}
//应用+终端+版本 维度
for (VersionDimensionKey versionKey : versionKeys) {
StatsUserDimensionKey userDimensionKey = new StatsUserDimensionKey();
StatsCommonDimensionKey commonKey = userDimensionKey.getCommonDimensionKey();
commonKey.setDateDimensionKey(dateKey);
commonKey.setAppDimensionKey(appKey);
commonKey.setPlatformDimensionKey(platformKey);
commonKey.setKpiDimensionKey(versionKpiKey);
userDimensionKey.setVersionDimensionKey(versionKey);
keys.add(userDimensionKey);
}
//应用+终端+地域+运营商 维度
for (AreaDimensionKey areaKey : areaKeys) {
for (IspDimensionKey ispKey : ispKeys) {
StatsUserDimensionKey userDimensionKey = new StatsUserDimensionKey();
StatsCommonDimensionKey commonKey = userDimensionKey.getCommonDimensionKey();
commonKey.setDateDimensionKey(dateKey);
commonKey.setAppDimensionKey(appKey);
commonKey.setPlatformDimensionKey(platformKey);
commonKey.setKpiDimensionKey(areaKpiKey);
userDimensionKey.setAreaDimensionKey(areaKey);
userDimensionKey.setIspDimensionKey(ispKey);
keys.add(userDimensionKey);
}
}
}
return keys;
}
}
reducer:对map端的key进行拉取,相同的key存入一个集合中 ,不同的组合key可能有相同的uuid,遍历value将uuid存入set集合求取他的长度就是
今天在七天前的留存人数
public class LoseUserReducer extends Reducer<StatsUserDimensionKey, Text, StatsUserDimensionKey, MapWritableValue> {
private MapWritableValue outputValue = new MapWritableValue();
private Set<String> unique = new HashSet<String>(); @Override
protected void reduce(StatsUserDimensionKey key, Iterable<Text> values, Context context)
throws IOException, InterruptedException {
this.unique.clear();
for (Text value : values) {
this.unique.add(value.toString());
} // 设置值
MapWritable map = new MapWritable();
map.put(new IntWritable(-1), new IntWritable(this.unique.size()));
this.outputValue.setValue(map); // 设置kpi
this.outputValue.setKpi(KpiEnum.valueOfName(key.getCommonDimensionKey().getKpiDimensionKey().getKpiName())); // 数据输出
context.write(key, outputValue);
}
}
输出到mysql:
 /**
* 输出数据, 当在reduce中调用context.write方法的时候,底层调用的是该方法
* 将Reduce输出的Key/Value写成特定的格式
* 自定义输出到MySQL的outputformat类
*/
public class TransformerOutputFormat extends OutputFormat<KeyBaseDimension, BaseStatsValueWritable> { /**
* 返回一个具体定义如何输出数据的对象, recordwriter被称为数据的输出器
* getRecordWriter用于返回一个RecordWriter的实例,Reduce任务在执行的时候就是利用这个实例来输出Key/Value的。
* (如果Job不需要Reduce,那么Map任务会直接使用这个实例来进行输出。)
*/
@Override
public RecordWriter<KeyBaseDimension, BaseStatsValueWritable> getRecordWriter(TaskAttemptContext context)
throws IOException, InterruptedException {
Configuration conf = context.getConfiguration();
/**
* 使用RPC方式创建converter,很重要,通过配置获取维度id
*/
IDimensionConverter converter = DimensionConverterClient.createDimensionConverter(conf);
Connection conn = null; try {
conn = JdbcManager.getConnection(conf, GlobalConstants.WAREHOUSE_OF_REPORT);
// 关闭自动提交机制
conn.setAutoCommit(false);
} catch (Exception e) {
throw new RuntimeException("获取数据库连接失败", e);
}
return new TransformerRecordWriter(conn, conf, converter);
} /**
* 执行reduce时,会验证输出目录是否存在,
* checkOutputSpecs是 在JobClient提交Job之前被调用的(在使用InputFomat进行输入数据划分之前),用于检测Job的输出路径。
* 比如,FileOutputFormat通过这个方法来确认在Job开始之前,Job的Output路径并不存在,然后该方法又会重新创建这个Output 路径。
* 这样一来,就能确保Job结束后,Output路径下的东西就是且仅是该Job输出的。
* @param context
* @throws IOException
* @throws InterruptedException
*/
@Override
public void checkOutputSpecs(JobContext context) throws IOException, InterruptedException {
// 这个方法在自己实现的时候不需要关注,如果你非要关注,最多检查一下表数据存在 } /**
* getOutputCommitter则 用于返回一个OutputCommitter的实例
* @param context
* @return
* @throws IOException
* @throws InterruptedException
*/
@Override
public OutputCommitter getOutputCommitter(TaskAttemptContext context) throws IOException, InterruptedException {
return new FileOutputCommitter(FileOutputFormat.getOutputPath(context), context);
} /**
* 自定义的数据输出器
*/
public class TransformerRecordWriter extends RecordWriter<KeyBaseDimension, BaseStatsValueWritable> { private Connection conn = null;
private Configuration conf = null;
private IDimensionConverter converter = null;
private Map<KpiEnum, PreparedStatement> kpiTypeSQLMap = new HashMap<>();
private Map<KpiEnum, Integer> batchMap = new HashMap<>(); public TransformerRecordWriter(Connection conn, Configuration conf, IDimensionConverter converter) {
super();
this.conn = conn;
this.conf = conf;
this.converter = converter;
} /**
* 输出数据, 当在reduce中调用context.write方法的时候,底层调用的是该方法
* 将Reduce输出的Key/Value写成特定的格式
* @param key
* @param value
* @throws IOException
* @throws InterruptedException
*/
@Override
public void write(KeyBaseDimension key, BaseStatsValueWritable value)
throws IOException, InterruptedException { KpiEnum kpiEnum = value.getKpi(); String sql = this.conf.get(kpiEnum.name);
PreparedStatement pstmt;
int count = 1;
try {
if (kpiTypeSQLMap.get(kpiEnum) == null) {
// 第一次创建
pstmt = this.conn.prepareStatement(sql);
kpiTypeSQLMap.put(kpiEnum, pstmt);
} else {
// 标示已经存在
pstmt = kpiTypeSQLMap.get(kpiEnum);
if (!batchMap.containsKey(kpiEnum)) {
batchMap.put(kpiEnum, count);
}
count = batchMap.get(kpiEnum);
count++;
}
batchMap.put(kpiEnum, count); // 针对特定的MR任务有特定的输出器:IOutputCollector
String collectorClassName = conf.get(GlobalConstants.OUTPUT_COLLECTOR_KEY_PREFIX + kpiEnum.name);
Class<?> clazz = Class.forName(collectorClassName);
// 创建对象, 要求实现子类一定要有一个无参数的构造方法
IOutputCollector collector = (IOutputCollector) clazz.newInstance();
collector.collect(conf, key, value, pstmt, converter); // 批量提交
if (count % conf.getInt(GlobalConstants.JDBC_BATCH_NUMBER, GlobalConstants.DEFAULT_JDBC_BATCH_NUMBER) == 0) {
pstmt.executeBatch(); // 批量提交
conn.commit();
batchMap.remove(kpiEnum); // 移除已经存在的输出数据
}
} catch (Exception e) {
throw new IOException("数据输出产生异常", e);
}
} /**
* 关闭资源使用,最终一定会调用
* 负责对输出做最后的确认并关闭输出
* @param context
* @throws IOException
* @throws InterruptedException
*/
@Override
public void close(TaskAttemptContext context) throws IOException, InterruptedException {
try {
try {
for (Map.Entry<KpiEnum, PreparedStatement> entry : this.kpiTypeSQLMap.entrySet()) {
entry.getValue().executeBatch();
}
} catch (Exception e) {
throw new IOException("输出数据出现异常", e);
} finally {
try {
if (conn != null) {
conn.commit();
}
} catch (Exception e) {
e.printStackTrace();
} finally {
if (conn != null) {
for (Map.Entry<KpiEnum, PreparedStatement> entry : this.kpiTypeSQLMap.entrySet()) {
try {
entry.getValue().close();
} catch (SQLException e) {
e.printStackTrace();
}
}
try {
conn.close();
} catch (SQLException e) {
e.printStackTrace();
}
}
}
}
} finally {
// 关闭远程连接
DimensionConverterClient.stopDimensionConverterProxy(converter);
}
} } }
 
04-21 09:43
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