[MDEV-26231] mysql_upgrade attempts to remove plugins which it failed to install Created: 2021-07-23  Updated: 2023-11-30

Status: In Review
Project: MariaDB Server
Component/s: Scripts & Clients
Affects Version/s: 10.5, 10.6
Fix Version/s: 10.5, 10.6

Type: Bug Priority: Minor
Reporter: Elena Stepanova Assignee: Vicențiu Ciorbaru
Resolution: Unresolved Votes: 0
Labels: None

Issue Links:
Relates
relates to MDEV-26230 mysql_upgrade fails to load type_mysq... Closed

 Description   

When mysql_upgrade is run on a MySQL datadir with JSON type, it attempts to install type_mysql_json. In reality, it is likely to fail (e.g. due to MDEV-26230).
Further in the logic it attempts to uninstall previously installed plugins. Since it failed to install this one, it should be skipped upon uninstallation, but it is not:

10.5 5518c320

 
Checking for tables with unknown storage engine
 
installing plugin for MYSQL_JSON data type
 
ERROR 1126 (HY000) at line 1: Can't open shared library 'type_mysql_json.so' (errno: 1, Loading of alpha plugin MYSQL_JSON is prohibited by --plugin-maturity=gamma)
 
Phase 3/7: Fixing views from mysql


test.t
 
Error    : Unknown data type: 'MYSQL_JSON'
 
error    : Corrupt
 
uninstalling plugin for 'type_mysql_json' data type
 
ERROR 1305 (42000) at line 1: SONAME type_mysql_json.so does not exist
 
Phase 7/7: Running 'FLUSH PRIVILEGES'



 Comments   
Comment by Anel Husakovic [ 2023-11-13 ]

Hi elenst,
since MDEV-26230 is fixed this may be closed,right?
I have tested on 10.6.16 and I don't see above behavior.

Comment by Elena Stepanova [ 2023-11-13 ]

Naturally you can't see the described behavior if the description uses type_mysql_json as an example of a failing plugin and it doesn't fail anymore. This report is not about that, it is about mysql_upgrade not detecting / remembering whether it succeeded at installing something before or not, and trying to uninstall it anyway.

So, if somebody can guarantee that no plugin will ever fail to install during mysql_upgrade, then sure, it can be closed on this reason.

Another reason to close it could be that it doesn't matter. I can't remember now why it mattered that mysql_upgrade throws an additional error, even a meaningless one. It looks like a cosmetic issue, so I'll decrease the priority.

Comment by Anel Husakovic [ 2023-11-14 ]

I have tried to create the verify the test case running the MariaDB mysql_upgrade binary on the MySQL 5.7 data directory.
The way I have done it was through containers

MySQL 5.7 datadir upgrade

 
# MySQL  server
 
$ docker run --name mysql-cont --rm -v"${PWD}/mysql-data-dir":/var/lib/mysql -p 127.0.0.1:3344:3306 -eMYSQL_ROOT_PASSWORD=secret -d mysql:5.7
 
# MariaDB client
 
$ ./client/mysql_upgrade -uroot -psecret -h127.0.0.1 -P3344 --protocol=tcp
 
Reading datadir from the MariaDB server failed. Got the following error when executing the 'mysql' command line client
 
ERROR 1193 (HY000) at line 1: Unknown system variable 'WSREP_ON'
 
FATAL ERROR: Upgrade failed
 
#  Noted that it {MariaDB}'s {mariadb} client binary was successful on connecting to the {MySQL} server
 
$ ./client/mariadb -uroot -psecret -h127.0.0.1 -P3344 --protocol=tcp
 
Welcome to the MariaDB monitor.  Commands end with ; or \g.
 
Your MySQL connection id is 4
 
Server version: 5.7.44 MySQL Community Server (GPL)
 
 
 
Copyright (c) 2000, 2018, Oracle, MariaDB Corporation Ab and others.
 
 
 
Type 'help;' or '\h' for help. Type '\c' to clear the current input statement.

The same was done on MySQL 8.0, just for testing and noted that caching_sha2_password is missing for tested mariadb and mysql_upgrade clients.

MySQL 8.0 datadir upgrade

 
# MySQL  server
 
$ docker run --name mysql-cont --rm -v"${PWD}/mysql-data-dir":/var/lib/mysql -p 127.0.0.1:3344:3306 -eMYSQL_ROOT_PASSWORD=secret -d mysql
 
# MariaDB client
 
$ ./client/mysql_upgrade -uroot -psecret -h127.0.0.1 -P3344 --protocol=tcp
 
Reading datadir from the MariaDB server failed. Got the following error when executing the 'mysql' command line client
 
ERROR 1045 (28000): Plugin caching_sha2_password could not be loaded: /usr/local/mysql/lib/plugin/caching_sha2_password.so: cannot open shared object file: No such file or directory
 
FATAL ERROR: Upgrade failed
 
 
 
# MariaDB client
 
$ ./client/mariadb -uroot -psecret -h127.0.0.1 -P3344 --protocol=tcp
 
ERROR 1045 (28000): Plugin caching_sha2_password could not be loaded: /usr/local/mysql/lib/plugin/caching_sha2_password.so: cannot open shared object file: No such file or directory

But in order to be sure that no error will be generated I'm suggesting the following patch

Patch: Check if plugin is installed via string

 
$ git diff
 
diff --git a/client/mysql_upgrade.c b/client/mysql_upgrade.c
 
index 617d5464e34..81e66ecf2c2 100644
 
--- a/client/mysql_upgrade.c
 
+++ b/client/mysql_upgrade.c
 
@@ -1124,7 +1124,7 @@ static my_bool from_before_10_1()
 
 
 static void uninstall_plugins(void)
 
 {
 
-  if (ds_plugin_data_types.length)
 
+  if (strcmp(ds_plugin_data_types.str, "") > 0)
 
   {
 
     char *plugins= ds_plugin_data_types.str;
 
     char *next= get_line(plugins);
 
@@ -1181,6 +1181,7 @@ static int install_used_plugin_data_types(void)
 
         else
 
         {
 
           fprintf(stderr, "... can't %s\n", "INSTALL SONAME 'type_mysql_json'");
 
+          dynstr_set(&ds_plugin_data_types, "");
 
           return 1;
 
         }
 
       }

Have created PR.
Regards,
Anel

Comment by Vicențiu Ciorbaru [ 2023-11-28 ]

Review sent. Need aditional input because the current patch doesn't seem to change anything logic wise.

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