【原创】大叔经验分享(7)创建hive表时格式如何选择

时间:2021-09-22 19:57:25

常用格式

textfile

需要定义分隔符,占用空间大,读写效率最低,非常容易发生冲突(分隔符)的一种格式,基本上只有需要导入数据的时候才会使用,比如导入csv文件;

ROW FORMAT DELIMITED

  FIELDS TERMINATED BY '\u0001'

  LINES TERMINATED BY '\n'

STORED AS TEXTFILE

json

hive3.0后官方支持json格式,之前需要使用第三方,导入jar,http://www.congiu.net/hive-json-serde/

add jar hdfs://nn/jarpath/json-udf-1.3.8-jar-with-dependencies.jar;
add jar hdfs://nn/jarpath/json-serde-1.3.8-jar-with-dependencies.jar;

占用空间最大,读写效率低,基本上只有需要导入数据的时候才会使用,比如导入json文件;

ROW FORMAT SERDE 'org.openx.data.jsonserde.JsonSerDe'
STORED AS TEXTFILE

lzo

相比textfile多了lzo压缩,占用空间更小;

ROW FORMAT DELIMITED
FIELDS TERMINATED BY '\t'
STORED AS INPUTFORMAT
'com.hadoop.mapred.DeprecatedLzoTextInputFormat'
OUTPUTFORMAT
'org.apache.hadoop.hive.ql.io.HiveIgnoreKeyTextOutputFormat'

orc

列式存储,占用空间最小,非常适合用来做数仓;

STORED AS ORC

压缩

STORED AS ORC TBLPROPERTIES ("orc.compression"="ZLIB")

STORED AS ORC TBLPROPERTIES ("orc.compression"="SNAPPY")

注意设置orc压缩格式前一定要先设置:

set hive.exec.orc.compression.strategy=COMPRESSION;

否则压缩不生效;

parquet

列式存储,占用空间居中,如果后期使用spark来处理,parquet是最佳格式;

 STORED AS PARQUET

parquet+snappy

STORED AS PARQUET TBLPROPERTIES ("parquet.compression"="SNAPPY")

 

对比测试

测试表:test_table

测试行数:10亿

测试sql类型:aggregation

测试sql:select col_1, count(1) from test_table group by col_1;

测试结果

fs

hdfs

kudu

format

textfile

lzo

parquet

parquet snappy

orc

orc snappy

 

capacity

464.0 G

169.4 G

177.2 G

111.3 G

71.5 G

65.7G

184 G

 

100%

36%

37%

23%

15%

14%

39%

Hive2.3.4

816 s

711 s

250 s

158 s

130 s

127 s

 

Hive2.3.4

Tuning

 

 

251 s

163 s

109 s

96 s

 

Hive2.3.4

On

spark2.4.0

 

 

54 s

47 s

149 s

138 s

 

Spark2.1.1

371 s

293 s

17 s

16 s

51 s

 

 

Spark2.4.0

496 s

297 s

16 s

16 s

21 s

21 s

 

Drill1.15.0

 

 

59 s

57 s

75 s

45 s

 

Impala2.12

 

 

 

15 s

 

 

16 s

Presto0.215

 

 

25 s

21 s

13 s

12 s

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

  • 从数据大小和查询效率上看,表现最好的是presto+orc+snappy;
  • hive下最佳格式为orc snappy,数据大小最小,并且查询最快;
  • hive切换engine为spark后,对parquet格式的查询有一些提升,但是占用相同资源的情况下,远不如直接使用spark sql快;
  • spark2.3以后对orc格式相比之前有很大优化,已经很接近parquet格式;
  • impala+parquet+hdfs的性能和impala+kudu差不多,kudu的好处是支持实时更新;
  • drill看起来没有必要;
  • spark2.4.0中的parquet为2.4,parquet从2.5开始支持column index,预计以后的spark版本对parquet的查询会更快;
  • impala对orc的支持从3.1开始作为实验功能的一部分;

 

详细数据

yarn 200g 50core

1 hive-2.3.4

set mapreduce.map.memory.mb=4096;
set mapreduce.map.java.opts=-Xmx3072m;

hive-textfile:
Time taken: 816.202 seconds, Fetched: 32 row(s)
Stage-Stage-1: Map: 1831 Reduce: 1009 Cumulative CPU: 27614.77 sec HDFS Read: 498267775168 HDFS Write: 88861 SUCCESS
Total MapReduce CPU Time Spent: 0 days 7 hours 40 minutes 14 seconds 770 msec

hive-lzo:
Time taken: 711.266 seconds, Fetched: 32 row(s)
Stage-Stage-1: Map: 183 Reduce: 711 Cumulative CPU: 13949.24 sec HDFS Read: 181881436157 HDFS Write: 62935 SUCCESS
Total MapReduce CPU Time Spent: 0 days 3 hours 52 minutes 29 seconds 240 msec

hive-orc:
Time taken: 130.194 seconds, Fetched: 32 row(s)
Stage-Stage-1: Map: 275 Reduce: 300 Cumulative CPU: 4368.67 sec HDFS Read: 626004573 HDFS Write: 27178 SUCCESS
Total MapReduce CPU Time Spent: 0 days 1 hours 12 minutes 48 seconds 670 msec

hive-orc snappy:
Time taken: 127.803 seconds, Fetched: 32 row(s)
Stage-Stage-1: Map: 191 Reduce: 276 Cumulative CPU: 4374.74 sec HDFS Read: 580889407 HDFS Write: 25090 SUCCESS
Total MapReduce CPU Time Spent: 0 days 1 hours 12 minutes 54 seconds 740 msec

hive-orc-tuning:
Time taken: 109.539 seconds, Fetched: 32 row(s)
Stage-Stage-1: Map: 275 Reduce: 300 Cumulative CPU: 3051.67 sec HDFS Read: 627064673 HDFS Write: 40321 SUCCESS
Total MapReduce CPU Time Spent: 50 minutes 51 seconds 670 msec

hive-orc snappy-tuning:
Time taken: 94.135 seconds, Fetched: 32 row(s)
Stage-Stage-1: Map: 191 Reduce: 276 Cumulative CPU: 2393.92 sec HDFS Read: 581727151 HDFS Write: 37201 SUCCESS
Total MapReduce CPU Time Spent: 39 minutes 53 seconds 920 msec

hive-parquet:
Time taken: 250.786 seconds, Fetched: 32 row(s)
Stage-Stage-1: Map: 642 Reduce: 744 Cumulative CPU: 10919.85 sec HDFS Read: 873784253 HDFS Write: 65806 SUCCESS
Total MapReduce CPU Time Spent: 0 days 3 hours 1 minutes 59 seconds 850 msec

hive-parquet snappy:
Time taken: 158.009 seconds, Fetched: 32 row(s)
Stage-Stage-1: Map: 367 Reduce: 467 Cumulative CPU: 6246.0 sec HDFS Read: 721915438 HDFS Write: 41707 SUCCESS
Total MapReduce CPU Time Spent: 0 days 1 hours 44 minutes 6 seconds 0 msec

2 hive-2.3.4 on spark-2.4.0

set spark.driver.memory=4g;
set spark.executor.memory=4g;
set spark.executor.instances=10;

hive on spark-parquet:
Time taken: 54.446 seconds, Fetched: 32 row(s)

hive on spark-parquet snappy:
Time taken: 47.364 seconds, Fetched: 32 row(s)

hive on spark-orc:
Time taken: 149.901 seconds, Fetched: 32 row(s)

hive on spark-orc snappy:
Time taken: 138.844 seconds, Fetched: 32 row(s)

3 impala-2.12

MEM_LIMIT=20g * 3

impala-parquet snappy:
Fetched 32 row(s) in 15.10s
+--------------+--------+----------+----------+-------+------------+-----------+---------------+---------------------------------------------------+
| Operator | #Hosts | Avg Time | Max Time | #Rows | Est. #Rows | Peak Mem | Est. Peak Mem | Detail |
+--------------+--------+----------+----------+-------+------------+-----------+---------------+---------------------------------------------------+
| 04:EXCHANGE | 1 | 211.45us | 211.45us | 32 | 50 | 208.00 KB | 0 B | UNPARTITIONED |
| 03:AGGREGATE | 3 | 2.58ms | 2.91ms | 32 | 50 | 34.03 MB | 128.00 MB | FINALIZE |
| 02:EXCHANGE | 3 | 29.23us | 30.92us | 96 | 1.04B | 32.00 KB | 0 B | HASH(cpp_addr_province) |
| 01:AGGREGATE | 3 | 13.29s | 13.97s | 96 | 1.04B | 34.05 MB | 128.00 MB | STREAMING |
| 00:SCAN HDFS | 3 | 723.09ms | 760.01ms | 1.04B | 1.04B | 36.55 MB | 88.00 MB | temp.app_ba_userprofile_prop_nonpolar_view_ext_ps |
+--------------+--------+----------+----------+-------+------------+-----------+---------------+---------------------------------------------------+

impala-kudu:
Fetched 32 row(s) in 15.61s

4 drill-1.15

10g+10g+1g+1g * 3

drill-parquet:
32 rows selected (59.501 seconds)

drill-parquet snappy:
32 rows selected (57.653 seconds)

drill-orc:
32 rows selected (75.749 seconds)

drill-orc snappy:
32 rows selected (45.323 seconds)

5 spark-sql --master yarn --num-executors 10 --executor-memory 4g --driver-memory 4g

5.1 spark-2.1.1

spark sql-textfile:
Time taken: 371.77 seconds, Fetched 32 row(s)

spark sql-lzo:
Time taken: 293.391 seconds, Fetched 32 row(s)

spark sql-parquet:
Time taken: 17.338 seconds, Fetched 32 row(s)

spark sql-parquet snappy:
Time taken: 16.609 seconds, Fetched 32 row(s)

spark sql-orc:
Time taken: 51.959 seconds, Fetched 32 row(s)


5.2 spark-2.4.0

spark sql-textfile:
Time taken: 496.395 seconds, Fetched 32 row(s)

spark sql-lzo:
Time taken: 297.142 seconds, Fetched 32 row(s)

spark sql-parquet:
Time taken: 16.728 seconds, Fetched 32 row(s)

spark sql-parquet snappy:
Time taken: 16.879 seconds, Fetched 32 row(s)

spark sql-orc:
Time taken: 21.432 seconds, Fetched 32 row(s)

spark sql-orc snappy:
Time taken: 21.935 seconds, Fetched 32 row(s)

 

6 presto

presto-parquet:
Splits: 3,182 total, 3,182 done (100.00%)
0:25 [1.04B rows, 612MB] [42.2M rows/s, 24.9MB/s]

presto-parquet snappy:
Splits: 2,088 total, 2,088 done (100.00%)
0:21 [1.04B rows, 584MB] [49.3M rows/s, 27.8MB/s

presto-orc:
Splits: 1,532 total, 1,532 done (100.00%)
0:13 [1.04B rows, 850MB] [81.7M rows/s, 66.8MB/s]

presto-orc snappy:
Splits: 1,353 total, 1,353 done (100.00%)
0:12 [1.04B rows, 1.13GB] [87.5M rows/s, 97.4MB/s]