Re: sha256_password deprecated warnings filling logs

[Greg Turner]

This is a brand new install, there are no users to migrate as all were created with the correct plugin:

SQL > select user, host, plugin from mysql.user;
+---------------------------------+-----------+-----------------------+
| user | host | plugin |
+---------------------------------+-----------+-----------------------+
| webapp | % | caching_sha2_password |
| mysql_innodb_cluster_1276292843 | % | caching_sha2_password |
| mysql_innodb_cluster_2043890000 | % | caching_sha2_password |
| mysql_innodb_cluster_2047920959 | % | caching_sha2_password |
| mysql_router10_hbhormyiqiwc | % | mysql_native_password |
| mysql_router11_ux2ml626arqw | % | mysql_native_password |
| mysql_router12_g847vidgk7oz | % | mysql_native_password |
| mysql_router13_8a11hzknc8lb | % | mysql_native_password |
| mysql_router14_z3p00lytw05r | % | mysql_native_password |
| mysql_router15_vaqexicgybsz | % | mysql_native_password |
| mysql_router16_pon3x3wv6qms | % | mysql_native_password |
| mysql_router17_x7z0agqaem0n | % | mysql_native_password |
| mysql_router18_f9id9e8z6kz5 | % | mysql_native_password |
| mysql_router1_4vnsu2whnq49 | % | mysql_native_password |
| mysql_router22_i0qd106q7a7y | % | mysql_native_password |
| mysql_router23_2dv1ox5pn1xu | % | mysql_native_password |
| mysql_router24_k0wkgx2id2sy | % | mysql_native_password |
| mysql_router25_borrfuqeh17s | % | mysql_native_password |
| mysql_router26_4lifpdfgabgs | % | mysql_native_password |
| mysql_router27_zogdakztdunt | % | mysql_native_password |
| mysql_router28_px3xvstrnaqu | % | mysql_native_password |
| mysql_router29_pek16cbmv6vk | % | mysql_native_password |
| mysql_router2_me424wcj7c0k | % | mysql_native_password |
| mysql_router30_hf1kpzglinvo | % | mysql_native_password |
| mysql_router3_qug9fk633if9 | % | mysql_native_password |
| mysql_router4_os7gsa9j5m43 | % | mysql_native_password |
| mysql_router5_132e0tahui5j | % | mysql_native_password |
| mysql_router6_mvzf2r27nl74 | % | mysql_native_password |
| mysql_router7_ghxssawhydoa | % | mysql_native_password |
| mysql_router8_6v8uzii1etxw | % | mysql_native_password |
| mysql_router8_pl6a23em6zs7 | % | mysql_native_password |
| mysql_router9_j9focotrzy8s | % | mysql_native_password |
| backup | localhost | caching_sha2_password |
| mysql.infoschema | localhost | caching_sha2_password |
| mysql.session | localhost | caching_sha2_password |
| mysql.sys | localhost | caching_sha2_password |
| root | localhost | caching_sha2_password |
+---------------------------------+-----------+-----------------------+

As you can see, my hunch is that it is coming from the auto-generated 'mysql-router*' users created by the MySQL Router applications since they are the only users continually executing queries. I'm unsure why they would be causing this warning message, but I have no other evidence that it would be anything else.