yum updateでHTTP Error 404がでる

yum updateをすると下のようなエラーがでました。

[root@ip- ]# yum update
読み込んだプラグイン:extras_suggestions, langpacks, priorities, update-motd
amzn2-core                                               | 3.7 kB     00:00
amzn2extra-docker                                        | 3.0 kB     00:00
amzn2extra-php7.2                                        | 3.0 kB     00:00
mysql-connectors-community                               | 2.5 kB     00:00
mysql-tools-community                                    | 2.5 kB     00:00
http://repo.mysql.com/yum/mysql-5.7-community/el/7/aarch64/repodata/repomd.xml: [Errno 14] HTTP Error 404 - Not Found
他のミラーを試します。


 One of the configured repositories failed (MySQL 5.7 Community Server),
 and yum doesn't have enough cached data to continue. At this point the only
 safe thing yum can do is fail. There are a few ways to work "fix" this:

     1. Contact the upstream for the repository and get them to fix the problem.

     2. Reconfigure the baseurl/etc. for the repository, to point to a working
        upstream. This is most often useful if you are using a newer
        distribution release than is supported by the repository (and the
        packages for the previous distribution release still work).

     3. Run the command with the repository temporarily disabled
            yum --disablerepo=mysql57-community ...

     4. Disable the repository permanently, so yum won't use it by default. Yum
        will then just ignore the repository until you permanently enable it
        again or use --enablerepo for temporary usage:

            yum-config-manager --disable mysql57-community
        or
            subscription-manager repos --disable=mysql57-community

     5. Configure the failing repository to be skipped, if it is unavailable.
        Note that yum will try to contact the repo. when it runs most commands,
        so will have to try and fail each time (and thus. yum will be be much
        slower). If it is a very temporary problem though, this is often a nice
        compromise:

            yum-config-manager --save --setopt=mysql57-community.skip_if_unavailable=true

failure: repodata/repomd.xml from mysql57-community: [Errno 256] No more mirrors to try.
http://repo.mysql.com/yum/mysql-5.7-community/el/7/aarch64/repodata/repomd.xml: [Errno 14] HTTP Error 404 - Not Found

yumが参照しているリポジトリが古いものであるというエラーです。

対策

  1. キャッシュを消す
rm -fr /var/cache/yum/* 
yum clean all
yum update
  1. リポジトリを無効にする

エラーが出ているリポジトリがとりあえず不要である場合、無効にすることでエラーは消えます

cd /etc/yum.repos.d
vi mysql-community.repo

#enabled=1を書き換えます
enabled=0
  1. ネットワークを確認する

上記をしてもyum updateでエラーが出る場合、別の原因としてネットワークが通じていない可能性があります。

ping www.yahoo.co.jp

pingしてみて正常に返ってこない場合ネットワークの状態を確認してみます

systemctl status network