前面已经讲过如何将log4j的日志输出到指定的hdfs目录,我们前面的指定目录为/flume/events。
如果想用hive来分析采集来的日志,我们可以将/flume/events下面的日志数据都load到hive中的表当中去。
如果了解hive的load data原理的话,还有一种更简便的方式,可以省去load data这一步,就是直接将sink1.hdfs.path指定为hive表的目录。
下面我将详细描述具体的操作步骤。
我们还是从需求驱动来讲解,前面我们采集的数据,都是接口的访问日志数据,数据格式是JSON格式如下:
{“requestTime”:1405651379758,”requestParams”:{“timestamp”:1405651377211,”phone”:”02038824941″,”cardName”:”测试商家名称”,”provinceCode”:”440000″,”cityCode”:”440106″},”requestUrl”:”/reporter-api/reporter/reporter12/init.do”}
现在有一个需求,我们要统计接口的总调用量。
我第一想法就是,hive中建一张表:test 然后将hdfs.path指定为tier1.sinks.sink1.hdfs.path=hdfs://master68:8020/user/hive/warehouse/besttone.db/test
然后select count(*) from test; 完事。
这个方案简单,粗暴,先这么干着。于是会遇到一个问题,我的日志数据时JSON格式的,需要hive来序列化和反序列化JSON格式的数据到test表的具体字段当中去。
这有点糟糕,因为hive本身没有提供JSON的SERDE,但是有提供函数来解析JSON字符串,
第一个是(UDF):
get_json_object(string json_string,string path) 从给定路径上的JSON字符串中抽取出JSON对象,并返回这个对象的JSON字符串形式,如果输入的JSON字符串是非法的,则返回NULL。
第二个是表生成函数(UDTF):json_tuple(string jsonstr,p1,p2,…,pn) 本函数可以接受多个标签名称,对输入的JSON字符串进行处理,这个和get_json_object这个UDF类似,不过更高效,其通过一次调用就可以获得多个键值,例:select b.* from test_json a lateral view json_tuple(a.id,’id’,’name’) b as f1,f2;通过lateral view行转列。
最理想的方式就是能有一种JSON SERDE,只要我们LOAD完数据,就直接可以select * from test,而不是select get_json_object这种方式来获取,N个字段就要解析N次,效率太低了。
好在cloudrea wiki里提供了一个json serde类(这个类没有在发行的hive的jar包中),于是我把它搬来了,如下:
- package com.besttone.hive.serde;
- import java.util.ArrayList;
- import java.util.Arrays;
- import java.util.HashMap;
- import java.util.List;
- import java.util.Map;
- import java.util.Properties;
- import org.apache.hadoop.conf.Configuration;
- import org.apache.hadoop.hive.serde.serdeConstants;
- import org.apache.hadoop.hive.serde2.SerDe;
- import org.apache.hadoop.hive.serde2.SerDeException;
- import org.apache.hadoop.hive.serde2.SerDeStats;
- import org.apache.hadoop.hive.serde2.objectinspector.ListObjectInspector;
- import org.apache.hadoop.hive.serde2.objectinspector.MapObjectInspector;
- import org.apache.hadoop.hive.serde2.objectinspector.ObjectInspector;
- import org.apache.hadoop.hive.serde2.objectinspector.PrimitiveObjectInspector;
- import org.apache.hadoop.hive.serde2.objectinspector.StructField;
- import org.apache.hadoop.hive.serde2.objectinspector.StructObjectInspector;
- import org.apache.hadoop.hive.serde2.typeinfo.ListTypeInfo;
- import org.apache.hadoop.hive.serde2.typeinfo.MapTypeInfo;
- import org.apache.hadoop.hive.serde2.typeinfo.StructTypeInfo;
- import org.apache.hadoop.hive.serde2.typeinfo.TypeInfo;
- import org.apache.hadoop.hive.serde2.typeinfo.TypeInfoFactory;
- import org.apache.hadoop.hive.serde2.typeinfo.TypeInfoUtils;
- import org.apache.hadoop.io.Text;
- import org.apache.hadoop.io.Writable;
- import org.codehaus.jackson.map.ObjectMapper;
- /**
- * This SerDe can be used for processing JSON data in Hive. It supports
- * arbitrary JSON data, and can handle all Hive types except for UNION. However,
- * the JSON data is expected to be a series of discrete records, rather than a
- * JSON array of objects.
- *
- * The Hive table is expected to contain columns with names corresponding to
- * fields in the JSON data, but it is not necessary for every JSON field to have
- * a corresponding Hive column. Those JSON fields will be ignored during
- * queries.
- *
- * Example:
- *
- * { “a”: 1, “b”: [ "str1", "str2" ], “c”: { “field1″: “val1″ } }
- *
- * Could correspond to a table:
- *
- * CREATE TABLE foo (a INT, b ARRAY<STRING>, c STRUCT<field1:STRING>);
- *
- * JSON objects can also interpreted as a Hive MAP type, so long as the keys and
- * values in the JSON object are all of the appropriate types. For example, in
- * the JSON above, another valid table declaraction would be:
- *
- * CREATE TABLE foo (a INT, b ARRAY<STRING>, c MAP<STRING,STRING>);
- *
- * Only STRING keys are supported for Hive MAPs.
- */
- public class JSONSerDe implements SerDe {
- private StructTypeInfo rowTypeInfo;
- private ObjectInspector rowOI;
- private List<String> colNames;
- private List<Object> row = new ArrayList<Object>();
- //遇到非JSON格式输入的时候的处理。
- private boolean ignoreInvalidInput;
- /**
- * An initialization function used to gather information about the table.
- * Typically, a SerDe implementation will be interested in the list of
- * column names and their types. That information will be used to help
- * perform actual serialization and deserialization of data.
- */
- @Override
- public void initialize(Configuration conf, Properties tbl)
- throws SerDeException {
- // 遇到无法转换成JSON对象的字符串时,是否忽略,默认不忽略,抛出异常,设置为true将跳过异常。
- ignoreInvalidInput = Boolean.valueOf(tbl.getProperty(
- “input.invalid.ignore”, “false”));
- // Get a list of the table’s column names.
- String colNamesStr = tbl.getProperty(serdeConstants.LIST_COLUMNS);
- colNames = Arrays.asList(colNamesStr.split(“,”));
- // Get a list of TypeInfos for the columns. This list lines up with
- // the list of column names.
- String colTypesStr = tbl.getProperty(serdeConstants.LIST_COLUMN_TYPES);
- List<TypeInfo> colTypes = TypeInfoUtils
- .getTypeInfosFromTypeString(colTypesStr);
- rowTypeInfo = (StructTypeInfo) TypeInfoFactory.getStructTypeInfo(
- colNames, colTypes);
- rowOI = TypeInfoUtils
- .getStandardJavaObjectInspectorFromTypeInfo(rowTypeInfo);
- }
- /**
- * This method does the work of deserializing a record into Java objects
- * that Hive can work with via the ObjectInspector interface. For this
- * SerDe, the blob that is passed in is a JSON string, and the Jackson JSON
- * parser is being used to translate the string into Java objects.
- *
- * The JSON deserialization works by taking the column names in the Hive
- * table, and looking up those fields in the parsed JSON object. If the
- * value of the field is not a primitive, the object is parsed further.
- */
- @Override
- public Object deserialize(Writable blob) throws SerDeException {
- Map<?, ?> root = null;
- row.clear();
- try {
- ObjectMapper mapper = new ObjectMapper();
- // This is really a Map<String, Object>. For more information about
- // how
- // Jackson parses JSON in this example, see
- // http://wiki.fasterxml.com/JacksonDataBinding
- root = mapper.readValue(blob.toString(), Map.class);
- } catch (Exception e) {
- // 如果为true,不抛出异常,忽略该行数据
- if (!ignoreInvalidInput)
- throw new SerDeException(e);
- else {
- return null;
- }
- }
- // Lowercase the keys as expected by hive
- Map<String, Object> lowerRoot = new HashMap();
- for (Map.Entry entry : root.entrySet()) {
- lowerRoot.put(((String) entry.getKey()).toLowerCase(),
- entry.getValue());
- }
- root = lowerRoot;
- Object value = null;
- for (String fieldName : rowTypeInfo.getAllStructFieldNames()) {
- try {
- TypeInfo fieldTypeInfo = rowTypeInfo
- .getStructFieldTypeInfo(fieldName);
- value = parseField(root.get(fieldName), fieldTypeInfo);
- } catch (Exception e) {
- value = null;
- }
- row.add(value);
- }
- return row;
- }
- /**
- * Parses a JSON object according to the Hive column’s type.
- *
- * @param field
- * – The JSON object to parse
- * @param fieldTypeInfo
- * – Metadata about the Hive column
- * @return – The parsed value of the field
- */
- private Object parseField(Object field, TypeInfo fieldTypeInfo) {
- switch (fieldTypeInfo.getCategory()) {
- case PRIMITIVE:
- // Jackson will return the right thing in this case, so just return
- // the object
- if (field instanceof String) {
- field = field.toString().replaceAll(“\n”, “\\\\n”);
- }
- return field;
- case LIST:
- return parseList(field, (ListTypeInfo) fieldTypeInfo);
- case MAP:
- return parseMap(field, (MapTypeInfo) fieldTypeInfo);
- case STRUCT:
- return parseStruct(field, (StructTypeInfo) fieldTypeInfo);
- case UNION:
- // Unsupported by JSON
- default:
- return null;
- }
- }
- /**
- * Parses a JSON object and its fields. The Hive metadata is used to
- * determine how to parse the object fields.
- *
- * @param field
- * – The JSON object to parse
- * @param fieldTypeInfo
- * – Metadata about the Hive column
- * @return – A map representing the object and its fields
- */
- private Object parseStruct(Object field, StructTypeInfo fieldTypeInfo) {
- Map<Object, Object> map = (Map<Object, Object>) field;
- ArrayList<TypeInfo> structTypes = fieldTypeInfo
- .getAllStructFieldTypeInfos();
- ArrayList<String> structNames = fieldTypeInfo.getAllStructFieldNames();
- List<Object> structRow = new ArrayList<Object>(structTypes.size());
- for (int i = 0; i < structNames.size(); i++) {
- structRow.add(parseField(map.get(structNames.get(i)),
- structTypes.get(i)));
- }
- return structRow;
- }
- /**
- * Parse a JSON list and its elements. This uses the Hive metadata for the
- * list elements to determine how to parse the elements.
- *
- * @param field
- * – The JSON list to parse
- * @param fieldTypeInfo
- * – Metadata about the Hive column
- * @return – A list of the parsed elements
- */
- private Object parseList(Object field, ListTypeInfo fieldTypeInfo) {
- ArrayList<Object> list = (ArrayList<Object>) field;
- TypeInfo elemTypeInfo = fieldTypeInfo.getListElementTypeInfo();
- for (int i = 0; i < list.size(); i++) {
- list.set(i, parseField(list.get(i), elemTypeInfo));
- }
- return list.toArray();
- }
- /**
- * Parse a JSON object as a map. This uses the Hive metadata for the map
- * values to determine how to parse the values. The map is assumed to have a
- * string for a key.
- *
- * @param field
- * – The JSON list to parse
- * @param fieldTypeInfo
- * – Metadata about the Hive column
- * @return
- */
- private Object parseMap(Object field, MapTypeInfo fieldTypeInfo) {
- Map<Object, Object> map = (Map<Object, Object>) field;
- TypeInfo valueTypeInfo = fieldTypeInfo.getMapValueTypeInfo();
- for (Map.Entry<Object, Object> entry : map.entrySet()) {
- map.put(entry.getKey(), parseField(entry.getValue(), valueTypeInfo));
- }
- return map;
- }
- /**
- * Return an ObjectInspector for the row of data
- */
- @Override
- public ObjectInspector getObjectInspector() throws SerDeException {
- return rowOI;
- }
- /**
- * Unimplemented
- */
- @Override
- public SerDeStats getSerDeStats() {
- return null;
- }
- /**
- * JSON is just a textual representation, so our serialized class is just
- * Text.
- */
- @Override
- public Class<? extends Writable> getSerializedClass() {
- return Text.class;
- }
- /**
- * This method takes an object representing a row of data from Hive, and
- * uses the ObjectInspector to get the data for each column and serialize
- * it. This implementation deparses the row into an object that Jackson can
- * easily serialize into a JSON blob.
- */
- @Override
- public Writable serialize(Object obj, ObjectInspector oi)
- throws SerDeException {
- Object deparsedObj = deparseRow(obj, oi);
- ObjectMapper mapper = new ObjectMapper();
- try {
- // Let Jackson do the work of serializing the object
- return new Text(mapper.writeValueAsString(deparsedObj));
- } catch (Exception e) {
- throw new SerDeException(e);
- }
- }
- /**
- * Deparse a Hive object into a Jackson-serializable object. This uses the
- * ObjectInspector to extract the column data.
- *
- * @param obj
- * – Hive object to deparse
- * @param oi
- * – ObjectInspector for the object
- * @return – A deparsed object
- */
- private Object deparseObject(Object obj, ObjectInspector oi) {
- switch (oi.getCategory()) {
- case LIST:
- return deparseList(obj, (ListObjectInspector) oi);
- case MAP:
- return deparseMap(obj, (MapObjectInspector) oi);
- case PRIMITIVE:
- return deparsePrimitive(obj, (PrimitiveObjectInspector) oi);
- case STRUCT:
- return deparseStruct(obj, (StructObjectInspector) oi, false);
- case UNION:
- // Unsupported by JSON
- default:
- return null;
- }
- }
- /**
- * Deparses a row of data. We have to treat this one differently from other
- * structs, because the field names for the root object do not match the
- * column names for the Hive table.
- *
- * @param obj
- * – Object representing the top-level row
- * @param structOI
- * – ObjectInspector for the row
- * @return – A deparsed row of data
- */
- private Object deparseRow(Object obj, ObjectInspector structOI) {
- return deparseStruct(obj, (StructObjectInspector) structOI, true);
- }
- /**
- * Deparses struct data into a serializable JSON object.
- *
- * @param obj
- * – Hive struct data
- * @param structOI
- * – ObjectInspector for the struct
- * @param isRow
- * – Whether or not this struct represents a top-level row
- * @return – A deparsed struct
- */
- private Object deparseStruct(Object obj, StructObjectInspector structOI,
- boolean isRow) {
- Map<Object, Object> struct = new HashMap<Object, Object>();
- List<? extends StructField> fields = structOI.getAllStructFieldRefs();
- for (int i = 0; i < fields.size(); i++) {
- StructField field = fields.get(i);
- // The top-level row object is treated slightly differently from
- // other
- // structs, because the field names for the row do not correctly
- // reflect
- // the Hive column names. For lower-level structs, we can get the
- // field
- // name from the associated StructField object.
- String fieldName = isRow ? colNames.get(i) : field.getFieldName();
- ObjectInspector fieldOI = field.getFieldObjectInspector();
- Object fieldObj = structOI.getStructFieldData(obj, field);
- struct.put(fieldName, deparseObject(fieldObj, fieldOI));
- }
- return struct;
- }
- /**
- * Deparses a primitive type.
- *
- * @param obj
- * – Hive object to deparse
- * @param oi
- * – ObjectInspector for the object
- * @return – A deparsed object
- */
- private Object deparsePrimitive(Object obj, PrimitiveObjectInspector primOI) {
- return primOI.getPrimitiveJavaObject(obj);
- }
- private Object deparseMap(Object obj, MapObjectInspector mapOI) {
- Map<Object, Object> map = new HashMap<Object, Object>();
- ObjectInspector mapValOI = mapOI.getMapValueObjectInspector();
- Map<?, ?> fields = mapOI.getMap(obj);
- for (Map.Entry<?, ?> field : fields.entrySet()) {
- Object fieldName = field.getKey();
- Object fieldObj = field.getValue();
- map.put(fieldName, deparseObject(fieldObj, mapValOI));
- }
- return map;
- }
- /**
- * Deparses a list and its elements.
- *
- * @param obj
- * – Hive object to deparse
- * @param oi
- * – ObjectInspector for the object
- * @return – A deparsed object
- */
- private Object deparseList(Object obj, ListObjectInspector listOI) {
- List<Object> list = new ArrayList<Object>();
- List<?> field = listOI.getList(obj);
- ObjectInspector elemOI = listOI.getListElementObjectInspector();
- for (Object elem : field) {
- list.add(deparseObject(elem, elemOI));
- }
- return list;
- }
- }
我稍微修改了一点东西,多加了一个参数input.invalid.ignore,对应的变量为:
//遇到非JSON格式输入的时候的处理。
private boolean ignoreInvalidInput;
在deserialize方法中原来是如果传入的是非JSON格式字符串的话,直接抛出了SerDeException,我加了一个参数来控制它是否抛出异常,在initialize方法中初始化这个变量(默认为false):
// 遇到无法转换成JSON对象的字符串时,是否忽略,默认不忽略,抛出异常,设置为true将跳过异常。
ignoreInvalidInput = Boolean.valueOf(tbl.getProperty(
“input.invalid.ignore”, “false”));
好的,现在将这个类打成JAR包: JSONSerDe.jar,放在hive_home的auxlib目录下(我的是/etc/hive/auxlib),然后修改hive-env.sh,添加HIVE_AUX_JARS_PATH=/etc/hive/auxlib/JSONSerDe.jar,这样每次运行hive客户端的时候都会将这个jar包添加到classpath,否则在设置SERDE的时候会报找不到类。
现在我们在HIVE中创建一张表用来存放日志数据:
- create table test(
- requestTime BIGINT,
- requestParams STRUCT<timestamp:BIGINT,phone:STRING,cardName:STRING,provinceCode:STRING,cityCode:STRING>,
- requestUrl STRING)
- row format serde “com.besttone.hive.serde.JSONSerDe”
- WITH SERDEPROPERTIES(
- “input.invalid.ignore”=”true”,
- “requestTime”=”$.requestTime”,
- “requestParams.timestamp”=”$.requestParams.timestamp”,
- “requestParams.phone”=”$.requestParams.phone”,
- “requestParams.cardName”=”$.requestParams.cardName”,
- “requestParams.provinceCode”=”$.requestParams.provinceCode”,
- “requestParams.cityCode”=”$.requestParams.cityCode”,
- “requestUrl”=”$.requestUrl”);
这个表结构就是按照日志格式设计的,还记得前面说过的日志数据如下:
{“requestTime”:1405651379758,”requestParams”:{“timestamp”:1405651377211,”phone”:”02038824941″,”cardName”:”测试商家名称”,”provinceCode”:”440000″,”cityCode”:”440106″},”requestUrl”:”/reporter-api/reporter/reporter12/init.do”}
我使用了一个STRUCT类型来保存requestParams的值,row format我们用的是自定义的json serde:com.besttone.hive.serde.JSONSerDe,SERDEPROPERTIES中,除了设置JSON对象的映射关系外,我还设置了一个自定义的参数:”input.invalid.ignore”=”true”,忽略掉所有非JSON格式的输入行。这里不是真正意义的忽略,只是非法行的每个输出字段都为NULL了,要在结果集上忽略,必须这样写:select * from test where requestUrl is not null;
OK表建好了,现在就差数据了,我们启动flumedemo的WriteLog,往hive表test目录下面输出一些日志数据,然后在进入hive客户端,select * from test;所以字段都正确的解析,大功告成。
flume.conf如下:
- tier1.sources=source1
- tier1.channels=channel1
- tier1.sinks=sink1
- tier1.sources.source1.type=avro
- tier1.sources.source1.bind=0.0.0.0
- tier1.sources.source1.port=44444
- tier1.sources.source1.channels=channel1
- tier1.sources.source1.interceptors=i1 i2
- tier1.sources.source1.interceptors.i1.type=regex_filter
- tier1.sources.source1.interceptors.i1.regex=\\{.*\\}
- tier1.sources.source1.interceptors.i2.type=timestamp
- tier1.channels.channel1.type=memory
- tier1.channels.channel1.capacity=10000
- tier1.channels.channel1.transactionCapacity=1000
- tier1.channels.channel1.keep-alive=30
- tier1.sinks.sink1.type=hdfs
- tier1.sinks.sink1.channel=channel1
- tier1.sinks.sink1.hdfs.path=hdfs://master68:8020/user/hive/warehouse/besttone.db/test
- tier1.sinks.sink1.hdfs.fileType=DataStream
- tier1.sinks.sink1.hdfs.writeFormat=Text
- tier1.sinks.sink1.hdfs.rollInterval=0
- tier1.sinks.sink1.hdfs.rollSize=10240
- tier1.sinks.sink1.hdfs.rollCount=0
- tier1.sinks.sink1.hdfs.idleTimeout=60
besttone.db是我在hive中创建的数据库,了解hive的应该理解没多大问题。
OK,到这篇文章为止,整个从LOG4J生产日志,到flume收集日志,再到用hive离线分析日志,一整套流水线都讲解完了。