使用Ambari搭建集群遇到的问题

使用Ambari-2.4.1.0+HDP-2.5.0.0+HDP-UTILS-1.1.0.21+CentOS7搭建集群，每次卡在Confirm Hosts步骤，一直处于安装状态或失败，查看报错日志；

ERROR 2018-05-18 14:13:02,566 NetUtil.py:88 - [SSL: CERTIFICATE_VERIFY_FAILED] certificate verify failed (_ssl.c:579)
ERROR 2018-05-18 14:13:02,566 NetUtil.py:89 - SSLError: Failed to connect. Please check openssl library versions. 
Refer to: https://bugzilla.redhat.com/show_bug.cgi?id=1022468 for more details.
WARNING 2018-05-18 14:13:02,568 NetUtil.py:116 - Server at https://amb71.hp:8440 is not reachable, sleeping for 10 seconds...

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初步以为是OpenSSL版本问题，但是查看系统版本是比较新的，更新后依然无法解决该问题

最后在官方论坛找到解决方法：

Your issue looks similar to : https://community.hortonworks.com/questions/120861/ambari-agent-ssl-certificate-verify-failed-certifi.html

So please check if you using Python version "python-2.7.5" or higher, if yes then you should try to either downgrade the python version to lower than python-2.7.5 as it causes this issue.

[SSL: CERTIFICATE_VERIFY_FAILED] certificate verify failed (_ssl.c:579)
(OR)

Else you will need to following the steps mentioned in the following doc to fix the "certificate verify failed (_ssl.c" issue while using RHEL7: Controlling and troubleshooting certificate verification

https://access.redhat.com/articles/2039753#controlling-certificate-verification-7

意思是，自带的Python版本大于或等于Python-2.7.5，需做如下修改：

修改文件：

vi /etc/python/cert-verification.cfg

将内容改为

[https]

verify=disable

注意：每个主机都要进行修改！