詳解Apache Hudi如何配置各種型別分割槽
阿新 • • 發佈：2020-08-18
## 1. 引入
Apache Hudi支援多種分割槽方式資料集，如多級分割槽、單分割槽、時間日期分割槽、無分割槽資料集等，使用者可根據實際需求選擇合適的分割槽方式，下面來詳細瞭解Hudi如何配置何種型別分割槽。
## 2. 分割槽處理
為說明Hudi對不同分割槽型別的處理，假定寫入Hudi的Schema如下
```json
{
"type" : "record",
"name" : "HudiSchemaDemo",
"namespace" : "hoodie.HudiSchemaDemo",
"fields" : [ {
"name" : "age",
"type" : [ "long", "null" ]
}, {
"name" : "location",
"type" : [ "string", "null" ]
}, {
"name" : "name",
"type" : [ "string", "null" ]
}, {
"name" : "sex",
"type" : [ "string", "null" ]
}, {
"name" : "ts",
"type" : [ "long", "null" ]
}, {
"name" : "date",
"type" : [ "string", "null" ]
} ]
}
```
其中一條具體資料如下
```json
{
"name": "zhangsan",
"ts": 1574297893837,
"age": 16,
"location": "beijing",
"sex":"male",
"date":"2020/08/16"
}
```
### 2.1 單分割槽
單分割槽表示使用一個欄位表示作為分割槽欄位的場景，可具體分為非日期格式欄位（如location）和日期格式欄位（如date）
### 2.1.1 非日期格式欄位分割槽
如使用上述location欄位做為分割槽欄位，在寫入Hudi並同步至Hive時配置如下
```java
df.write().format("org.apache.hudi").
options(getQuickstartWriteConfigs()).
option(DataSourceWriteOptions.TABLE_TYPE_OPT_KEY(), "COPY_ON_WRITE").
option(DataSourceWriteOptions.PRECOMBINE_FIELD_OPT_KEY(), "ts").
option(DataSourceWriteOptions.RECORDKEY_FIELD_OPT_KEY(), "name").
option(DataSourceWriteOptions.PARTITIONPATH_FIELD_OPT_KEY(), partitionFields).
option(DataSourceWriteOptions.KEYGENERATOR_CLASS_OPT_KEY(), keyGenerator).
option(TABLE_NAME, tableName).
option("hoodie.datasource.hive_sync.enable", true).
option("hoodie.datasource.hive_sync.table", tableName).
option("hoodie.datasource.hive_sync.username", "root").
option("hoodie.datasource.hive_sync.password", "123456").
option("hoodie.datasource.hive_sync.jdbcurl", "jdbc:hive2://localhost:10000").
option("hoodie.datasource.hive_sync.partition_fields", hivePartitionFields).
option("hoodie.datasource.write.table.type", "COPY_ON_WRITE").
option("hoodie.embed.timeline.server", false).
option("hoodie.datasource.hive_sync.partition_extractor_class", hivePartitionExtractorClass).
mode(saveMode).
save(basePath);
```
值得注意如下幾個配置項
* `DataSourceWriteOptions.PARTITIONPATH_FIELD_OPT_KEY()`配置為`location`；
* `hoodie.datasource.hive_sync.partition_fields`配置為`location`，與寫入Hudi的分割槽欄位相同；
* **`DataSourceWriteOptions.KEYGENERATOR_CLASS_OPT_KEY()`配置為`org.apache.hudi.keygen.SimpleKeyGenerator`，或者不配置該選項，預設為`org.apache.hudi.keygen.SimpleKeyGenerator`**；
* **`hoodie.datasource.hive_sync.partition_extractor_class`配置為`org.apache.hudi.hive.MultiPartKeysValueExtractor`**；
Hudi同步到Hive建立的表如下
```sql
CREATE EXTERNAL TABLE `notdateformatsinglepartitiondemo`(
`_hoodie_commit_time` string,
`_hoodie_commit_seqno` string,
`_hoodie_record_key` string,
`_hoodie_partition_path` string,
`_hoodie_file_name` string,
`age` bigint,
`date` string,
`name` string,
`sex` string,
`ts` bigint)
PARTITIONED BY (
`location` string)
ROW FORMAT SERDE
'org.apache.hadoop.hive.ql.io.parquet.serde.ParquetHiveSerDe'
STORED AS INPUTFORMAT
'org.apache.hudi.hadoop.HoodieParquetInputFormat'
OUTPUTFORMAT
'org.apache.hadoop.hive.ql.io.parquet.MapredParquetOutputFormat'
LOCATION
'file:/tmp/hudi-partitions/notDateFormatSinglePartitionDemo'
TBLPROPERTIES (
'last_commit_time_sync'='20200816154250',
'transient_lastDdlTime'='1597563780')
```
查詢表`notdateformatsinglepartitiondemo`
**tips: 查詢時請先將hudi-hive-sync-bundle-xxx.jar包放入$HIVE_HOME/lib下**
### 2.1.2 日期格式分割槽
如使用上述date欄位做為分割槽欄位，核心配置項如下
* `DataSourceWriteOptions.PARTITIONPATH_FIELD_OPT_KEY()`配置為`date`；
* `hoodie.datasource.hive_sync.partition_fields`配置為`date`，與寫入Hudi的分割槽欄位相同；
* **`DataSourceWriteOptions.KEYGENERATOR_CLASS_OPT_KEY()`配置為`org.apache.hudi.keygen.SimpleKeyGenerator`，或者不配置該選項，預設為`org.apache.hudi.keygen.SimpleKeyGenerator`**；
* **`hoodie.datasource.hive_sync.partition_extractor_class`配置為`org.apache.hudi.hive.SlashEncodedDayPartitionValueExtractor`**；
Hudi同步到Hive建立的表如下
```sql
CREATE EXTERNAL TABLE `dateformatsinglepartitiondemo`(
`_hoodie_commit_time` string,
`_hoodie_commit_seqno` string,
`_hoodie_record_key` string,
`_hoodie_partition_path` string,
`_hoodie_file_name` string,
`age` bigint,
`location` string,
`name` string,
`sex` string,
`ts` bigint)
PARTITIONED BY (
`date` string)
ROW FORMAT SERDE
'org.apache.hadoop.hive.ql.io.parquet.serde.ParquetHiveSerDe'
STORED AS INPUTFORMAT
'org.apache.hudi.hadoop.HoodieParquetInputFormat'
OUTPUTFORMAT
'org.apache.hadoop.hive.ql.io.parquet.MapredParquetOutputFormat'
LOCATION
'file:/tmp/hudi-partitions/dateFormatSinglePartitionDemo'
TBLPROPERTIES (
'last_commit_time_sync'='20200816155107',
'transient_lastDdlTime'='1597564276')
```
查詢表`dateformatsinglepartitiondemo`
### 2.2 多分割槽
多分割槽表示使用多個欄位表示作為分割槽欄位的場景，如上述使用location欄位和sex欄位，核心配置項如下
* `DataSourceWriteOptions.PARTITIONPATH_FIELD_OPT_KEY()`配置為`location,sex`；
* `hoodie.datasource.hive_sync.partition_fields`配置為`location,sex`，與寫入Hudi的分割槽欄位相同；
* **`DataSourceWriteOptions.KEYGENERATOR_CLASS_OPT_KEY()`配置為`org.apache.hudi.keygen.ComplexKeyGenerator`**；
* **`hoodie.datasource.hive_sync.partition_extractor_class`配置為`org.apache.hudi.hive.MultiPartKeysValueExtractor`**；
Hudi同步到Hive建立的表如下
```sql
CREATE EXTERNAL TABLE `multipartitiondemo`(
`_hoodie_commit_time` string,
`_hoodie_commit_seqno` string,
`_hoodie_record_key` string,
`_hoodie_partition_path` string,
`_hoodie_file_name` string,
`age` bigint,
`date` string,
`name` string,
`ts` bigint)
PARTITIONED BY (
`location` string,
`sex` string)
ROW FORMAT SERDE
'org.apache.hadoop.hive.ql.io.parquet.serde.ParquetHiveSerDe'
STORED AS INPUTFORMAT
'org.apache.hudi.hadoop.HoodieParquetInputFormat'
OUTPUTFORMAT
'org.apache.hadoop.hive.ql.io.parquet.MapredParquetOutputFormat'
LOCATION
'file:/tmp/hudi-partitions/multiPartitionDemo'
TBLPROPERTIES (
'last_commit_time_sync'='20200816160557',
'transient_lastDdlTime'='1597565166')
```
查詢表`multipartitiondemo`
### 2.3 無分割槽
無分割槽場景是指無分割槽欄位，寫入Hudi的資料集無分割槽。核心配置如下
* `DataSourceWriteOptions.PARTITIONPATH_FIELD_OPT_KEY()`配置為空字串；
* `hoodie.datasource.hive_sync.partition_fields`配置為空字串，與寫入Hudi的分割槽欄位相同；
* **`DataSourceWriteOptions.KEYGENERATOR_CLASS_OPT_KEY()`配置為`org.apache.hudi.keygen.NonpartitionedKeyGenerator`**；
* **`hoodie.datasource.hive_sync.partition_extractor_class`配置為`org.apache.hudi.hive.NonPartitionedExtractor`**；
Hudi同步到Hive建立的表如下
```sql
CREATE EXTERNAL TABLE `nonpartitiondemo`(
`_hoodie_commit_time` string,
`_hoodie_commit_seqno` string,
`_hoodie_record_key` string,
`_hoodie_partition_path` string,
`_hoodie_file_name` string,
`age` bigint,
`date` string,
`location` string,
`name` string,
`sex` string,
`ts` bigint)
ROW FORMAT SERDE
'org.apache.hadoop.hive.ql.io.parquet.serde.ParquetHiveSerDe'
STORED AS INPUTFORMAT
'org.apache.hudi.hadoop.HoodieParquetInputFormat'
OUTPUTFORMAT
'org.apache.hadoop.hive.ql.io.parquet.MapredParquetOutputFormat'
LOCATION
'file:/tmp/hudi-partitions/nonPartitionDemo'
TBLPROPERTIES (
'last_commit_time_sync'='20200816161558',
'transient_lastDdlTime'='1597565767')
```
查詢表`nonpartitiondemo`
### 2.4 Hive風格分割槽
除了上述幾種常見的分割槽方式，還有一種Hive風格分割槽格式，如location=beijing/sex=male格式，以`location,sex`作為分割槽欄位，核心配置如下
* `DataSourceWriteOptions.PARTITIONPATH_FIELD_OPT_KEY()`配置為`location,sex`；
* `hoodie.datasource.hive_sync.partition_fields`配置為`location,sex`，與寫入Hudi的分割槽欄位相同；
* **`DataSourceWriteOptions.KEYGENERATOR_CLASS_OPT_KEY()`配置為`org.apache.hudi.keygen.ComplexKeyGenerator`**；
* **`hoodie.datasource.hive_sync.partition_extractor_class`配置為`org.apache.hudi.hive.SlashEncodedDayPartitionValueExtractor`**；
* **`DataSourceWriteOptions.HIVE_STYLE_PARTITIONING_OPT_KEY()`配置為`true`**；
生成的Hudi資料集目錄結構會為如下格式
```shell
/location=beijing/sex=male
```
Hudi同步到Hive建立的表如下
```sql
CREATE EXTERNAL TABLE `hivestylepartitiondemo`(
`_hoodie_commit_time` string,
`_hoodie_commit_seqno` string,
`_hoodie_record_key` string,
`_hoodie_partition_path` string,
`_hoodie_file_name` string,
`age` bigint,
`date` string,
`name` string,
`ts` bigint)
PARTITIONED BY (
`location` string,
`sex` string)
ROW FORMAT SERDE
'org.apache.hadoop.hive.ql.io.parquet.serde.ParquetHiveSerDe'
STORED AS INPUTFORMAT
'org.apache.hudi.hadoop.HoodieParquetInputFormat'
OUTPUTFORMAT
'org.apache.hadoop.hive.ql.io.parquet.MapredParquetOutputFormat'
LOCATION
'file:/tmp/hudi-partitions/hiveStylePartitionDemo'
TBLPROPERTIES (
'last_commit_time_sync'='20200816172710',
'transient_lastDdlTime'='1597570039')
```
查詢表`hivestylepartitiondemo`
## 3. 總結
本篇文章介紹了Hudi如何處理不同分割槽場景，上述配置的分割槽類配置可以滿足絕大多數場景，當然Hudi非常靈活，還支援自定義分割槽解析器，具體可檢視`KeyGenerator`和`PartitionValueExtractor`類，其中所有寫入Hudi的分割槽欄位生成器都是`KeyGenerator`的子類，所有同步至Hive的分割槽值解析器都是`PartitionValueExtractor`的子類。上述示例程式碼都已經上傳至[https://github.com/leesf/hudi-demos](https://github.com/leesf/hudi-demos)，該倉庫會持續補充各種使用Hudi的Demo，方便開發者快速瞭解Hudi，構建企業級資料湖，歡迎star &