sparkstreaming 实时读取kafka写入hive优化（高流量）

背景：

kafka流量在800M/s,前任留下的程序大量数据丢失，且逻辑生成复杂，查询hive直接奔溃，优化从两方面，程序优化及小文件合并（生成结果产生大量小文件）

程序直接上代码，啥也不说了

程序

def main(args: Array[String]): Unit = {
val sdf = new SimpleDateFormat("yyyyMMddHHmm")
val broker_list = "XXXX";
val zk = "xxx";
val confSpark = new SparkConf()
.setAppName("kafka2hive")
.set("spark.serializer", "org.apache.spark.serializer.KryoSerializer")
.set("spark.rdd.compress", "true")
.set("spark.sql.shuffle.partitions", "512") //生成的partition根据kafka topic 分区生成，这个配置项貌似没效果
.set("spark.streaming.stopGracefullyOnShutdown", "true") //能够处理完最后一批数据，再关闭程序，不会发生强制kill导致数据处理中断，没处理完的数据丢失
.set("spark.streaming.backpressure.enabled","true")//开启后spark自动根据系统负载选择最优消费速率
.set("spark.shuffle.manager", "sort")
.set("spark.locality.wait", "5ms")
//.setMaster("local[*]")

val kafkaMapParams = Map(
"auto.offset.reset" -> "largest",
"group.id" -> "kafka2dhive",
"zookeeper.session.timeout.ms" -> "40000",
"metadata.broker.list" -> broker_list,
"zookeeper.connect" -> zk
)
val topicsSet = Set("innerBashData")
val sc = new SparkContext(confSpark)
val ssc = new StreamingContext(sc,Seconds(30)) //这个是重点微批处理，根据自己的机器资源，测试调整
val sqlContext = new HiveContext(sc)
var daily = sdf.format(new Date()).substring(0,8)
var dailyTableName = "bashdata"+daily;
val schema = StructType(
StructField("ver", StringType, true) ::
StructField("session_id", StringType, true) ::
StructField("host_time", StringType, true) ::
StructField("host_name", StringType, true) ::
StructField("src_ip", StringType, true) ::
Nil)

sqlContext.sql(s"""create table if not exists $dailyTableName(
a string ,
b string ,
c string ,
d string ,
e string
)
PARTITIONED BY (hours string,min string)
ROW FORMAT SERDE 'org.apache.hadoop.hive.ql.io.parquet.serde.ParquetHiveSerDe'
STORED AS INPUTFORMAT 'org.apache.hadoop.hive.ql.io.parquet.MapredParquetInputFormat'
OUTPUTFORMAT 'org.apache.hadoop.hive.ql.io.parquet.MapredParquetOutputFormat'
""".stripMargin)

val lines = KafkaUtils.createDirectStream[String, String, StringDecoder, StringDecoder](ssc, kafkaMapParams, topicsSet)
lines.foreachRDD( beforerdd => {
val rdd = beforerdd.map( rdd1 => {
rdd1._2
})
rdd.cache()

val agentDataFrame = sqlContext.read.schema(schema).json(rdd)
// .coalesce(10) //控制文件输出个数
agentDataFrame.registerTempTable("tmp_bashdata")
sqlContext.sql("set hive.exec.dynamic.partition = true")
sqlContext.sql("set hive.exec.dynamic.partition.mode = nonstrict")
sqlContext.sql("set hive.mapred.supports.subdirectories=true")
sqlContext.sql("set mapreduce.input.fileinputformat.input.dir.recursive=true")
sqlContext.sql("set mapred.max.split.size=256000000")
sqlContext.sql("set mapred.min.split.size.per.node=128000000")
sqlContext.sql("set mapred.min.split.size.per.rack=128000000")
sqlContext.sql("set hive.merge.mapfiles=true")
sqlContext.sql("set hive.merge.mapredfiles=true")
sqlContext.sql("set hive.merge.size.per.task=256000000")
sqlContext.sql("set hive.merge.smallfiles.avgsize=256000000")
sqlContext.sql("set hive.groupby.skewindata=true")

var hours = sdf.format(new Date()).substring(8,10)
var min = sdf.format(new Date()).substring(10,12) //每10分钟生成一个文件夹，这tm数据量也够大的
sqlContext.sql(
s"""
|INSERT OVERWRITE TABLE $dailyTableName PARTITION(hours='$hours', min='$min')
|SELECT
| a,
| b,
| c,
| d,
| e
|FROM tmp_bashdata
""".stripMargin)

});
ssc.start()
ssc.awaitTermination()

小文件合并

核心思想是重新生成一张表，指定分区数。脚本如下：

set mapred.reduce.tasks=5;
set mapred.max.split.size=512000000;
insert into table yhtable PARTITION(hours=14,min=1)
select
ver,
session_id,
host_time,
host_name,
src_ip
from aa20190624 where hours=14 and min=0;

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原文链接：https://blog.csdn.net/silentanytime/article/details/94395713