Hive的执行引擎Tez、spark出现的问题

Hive on Tez中，切换成mr引擎出现以下问题：

hadoop版本为2.7.3

tez版本为0.9.1

因为tez安装目录中应该有hadoop-mapreduce-client-core、hadoop-mapreduce-client-common等jar，hadoop中也有hadoop-mapreduce-client-core、hadoop-mapreduce-client-common等jar，确认他们的版本是否相同，如果不同，会有这个问题；

解决：将tez低版本的jar替换成2.7.3版本即可。

这是我替换后的，重新进入即可。

Spark引擎报错

hive> set hive.execution.engine=spark;
hive> select count(*) from wyp;
Query ID = hdfs_20200902101245_96089374-8a76-48d7-8d14-7ac61315b8b6
Total jobs = 1
Launching Job 1 out of 1
In order to change the average load for a reducer (in bytes):
  set hive.exec.reducers.bytes.per.reducer=
In order to limit the maximum number of reducers:
  set hive.exec.reducers.max=
In order to set a constant number of reducers:
  set mapreduce.job.reduces=
Failed to execute spark task, with exception 'org.apache.hadoop.hive.ql.metadata.HiveException(Failed to create spark client.)'
FAILED: Execution Error, return code 1 from org.apache.hadoop.hive.ql.exec.spark.SparkTask. Failed to create spark client.

解决方法

cd $SPARK_HOME/jars
rm -f hive-*
rm -rf spark-hive_*