初次使用Sqoop报错，sqoop命令不能正常使用：hcatalog does not exist!accumulo does not exist!

1、问题描述：

（1）问题示例：

[hadoop@master Tmp]$ sqoop  help
Warning: /home/grid/Sqoop/sqoop-1.4.7/../hcatalog does not exist! HCatalog jobs will fail.
Please set $HCAT_HOME to the root of your HCatalog installation.
Warning: /home/grid/Sqoop/sqoop-1.4.7/../accumulo does not exist! Accumulo imports will fail.
Please set $ACCUMULO_HOME to the root of your Accumulo installation.
No such sqoop tool: -help. See 'sqoop help'.
[hadoop@master Tmp]$ sqoop  version
Warning: /home/grid/Sqoop/sqoop-1.4.7/../hcatalog does not exist! HCatalog jobs will fail.
Please set $HCAT_HOME to the root of your HCatalog installation.
Warning: /home/grid/Sqoop/sqoop-1.4.7/../accumulo does not exist! Accumulo imports will fail.
Please set $ACCUMULO_HOME to the root of your Accumulo installation.
No such sqoop tool: -version. See 'sqoop help'.

（2）问题综述：

　　　　Sqoop工具的命令：sqoop不能正常使用，连-help查看参数、-version显示版本信息都报错。

　　　　问题的关键是：找不到，HCatalog和accumulo，这两个工具。

2、解决方案：

参考：https://blog.csdn.net/weixin_43716338/article/details/106752816

（1）找到Sqoop的配置文件：configure-sqoop

（2）找到如下段代码：

## Moved to be a runtime check in sqoop.
if [ ! -d "${HCAT_HOME}" ]; then
echo "Warning: $HCAT_HOME does not exist! HCatalog jobs will fail."
echo 'Please set $HCAT_HOME to the root of your HCatalog installation.'
fi

if [ ! -d "${ACCUMULO_HOME}" ]; then
echo "Warning: $ACCUMULO_HOME does not exist! Accumulo imports will fail."
echo 'Please set $ACCUMULO_HOME to the root of your Accumulo installation.'
fi

（3）上述代码全部用“#”注释掉，如下所示：

## Moved to be a runtime check in sqoop.
#if [ ! -d "${HCAT_HOME}" ]; then
# echo "Warning: $HCAT_HOME does not exist! HCatalog jobs will fail."
# echo 'Please set $HCAT_HOME to the root of your HCatalog installation.'
#fi

#if [ ! -d "${ACCUMULO_HOME}" ]; then
# echo "Warning: $ACCUMULO_HOME does not exist! Accumulo imports will fail."
# echo 'Please set $ACCUMULO_HOME to the root of your Accumulo installation.'
#fi

（4）结果检验：

[Hadoop@master Tmp]$ sqoop help
2021-11-05 00:55:21,339 INFO sqoop.Sqoop: Running Sqoop version: 1.4.7
usage: sqoop COMMAND [ARGS]

Available commands:

codegen 　　 　　　  Generate code to interact with database records
create-hive-table 　　 Import a table definition into Hive
eval　　 　　　　 　   Evaluate a SQL statement and display the results
export 　　 　　　　  Export an HDFS directory to a database table
help　　 　　　　　   List available commands
import　　      　　　  Import a table from a database to HDFS
import-all-tables 　　  Import tables from a database to HDFS
import-mainframe 　   Import datasets from a mainframe server to HDFS
job 　　　　　　　　 Work with saved jobs
list-databases 　　　  List available databases on a server
list-tables 　　　　     List available tables in a database
merge 　　　　 　　   Merge results of incremental imports
metast　　　　　　   ore Run a standalone Sqoop metastore
version 　　　　　　 Display version information

See 'sqoop help COMMAND' for information on a specific command.
[Hadoop@master Tmp]$ sqoop version
2021-11-05 00:55:33,567 INFO sqoop.Sqoop: Running Sqoop version: 1.4.7
Sqoop 1.4.7
git commit id 2328971411f57f0cb683dfb79d19d4d19d185dd8
Compiled by maugli on Thu Dec 21 15:59:58 STD 2017

3、问题剖析：

　　就是检测上述环境变量（${HCAT_HOME}和${ACCUMULO_HOME}）是否存在，通常工具 HCatalog和Accumulo，要么没有安装，要么安装时改变了通常意义上（系统默认）的安装位置。笔者改变了上述安装位置，所以才导致上述报错。