mariadb 10.4 does not work correctly.

[morgo]

Overview of the Issue

MariaDB is now supported by mysqlctl, but it fails the simple local example in reparenting. We will need to investigate the reason and fix it.

[pedroalb]

Hi team! Do you have any plans for when to fully support MariaDB 10.4? Thanks

[deepthi]

@askdba can you post the latest status here?

[askdba]

Currently, we're evaluating and testing MariaDB 10.4 compatibility and engaging with MariaDB to resolve this issue. We plan to make progress in the coming weeks on this.

[pedroalb]

Thanks @askdba !

[askdba]

Started investigating this issue with local docker build against MariaDB 10.4

There were initial errors:

    /vt/src/vitess.io/vitess/go/cmd/vtctldclient/main.go:41 +0x126
I0127 12:51:28.973345    1038 main.go:67] I0127 12:51:28.970629 tablet_executor.go:240] Received DDL request. strategy=direct
W0127 12:51:38.986194    1038 main.go:67] W0127 12:51:38.984720 schema.go:107] Failed to reload schema on replica tablet zone1-0000000102 in commerce/0 (use vtctl ReloadSchema to try again): rpc error: code = DeadlineExceeded desc = context deadline exceeded
W0127 12:51:38.988819    1038 main.go:67] W0127 12:51:38.985909 schema.go:107] Failed to reload schema on replica tablet zone1-0000000101 in commerce/0 (use vtctl ReloadSchema to try again): rpc error: code = DeadlineExceeded desc = context deadline exceeded
I0127 12:51:38.991125    1038 main.go:67] I0127 12:51:38.990194 tablet_executor.go:240] Received DDL request. strategy=direct
W0127 12:51:49.003539    1038 main.go:67] W0127 12:51:49.002249 schema.go:107] Failed to reload schema on replica tablet zone1-0000000102 in commerce/0 (use vtctl ReloadSchema to try again): rpc error: code = DeadlineExceeded desc = context deadline exceeded
W0127 12:51:49.005873    1038 main.go:67] W0127 12:51:49.002366 schema.go:107] Failed to reload schema on replica tablet zone1-0000000101 in commerce/0 (use vtctl ReloadSchema to try again): rpc error: code = DeadlineExceeded desc = context deadline exceeded
I0127 12:51:49.006843    1038 main.go:67] I0127 12:51:49.002479 tablet_executor.go:240] Received DDL request. strategy=direct
W0127 12:51:59.020102    1038 main.go:67] W0127 12:51:59.017486 schema.go:107] Failed to reload schema on replica tablet zone1-0000000102 in commerce/0 (use vtctl ReloadSchema to try again): rpc error: code = DeadlineExceeded desc = context deadline exceeded
W0127 12:51:59.020863    1038 main.go:67] W0127 12:51:59.017623 schema.go:107] Failed to reload schema on replica tablet zone1-0000000101 in commerce/0 (use vtctl ReloadSchema to try again): rpc error: code = DeadlineExceeded desc = context deadline exceeded
New VSchema object:

Later cluster came up as follows:

Welcome to the MariaDB monitor.  Commands end with ; or \g.
Your MySQL connection id is 1
Server version: 5.7.9-Vitess mariadb.org binary distribution

Copyright (c) 2000, 2018, Oracle, MariaDB Corporation Ab and others.

Type 'help;' or '\h' for help. Type '\c' to clear the current input statement.

MySQL [(none)]> \s
--------------
mysql  Ver 15.1 Distrib 10.4.17-MariaDB, for debian-linux-gnu (x86_64) using readline 5.2

Connection id:      1
Current database:
Current user:       vt_app@localhost
SSL:            Not in use
Current pager:      stdout
Using outfile:      ''
Using delimiter:    ;
Server:         MySQL
Server version:     5.7.9-Vitess mariadb.org binary distribution
Protocol version:   10
Connection:     127.0.0.1 via TCP/IP
Server characterset:    utf8
Db     characterset:    utf8
Client characterset:    utf8
Conn.  characterset:    utf8
TCP port:       15306
--------------

MySQL [(none)]> select @@version;
+--------------------------------------------+
| @@version                                  |
+--------------------------------------------+
| 10.4.17-MariaDB-1:10.4.17+maria~buster-log |
+--------------------------------------------+
1 row in set (0.003 sec)

Only single tablet serving :

MySQL [(none)]> show vitess_tablets;
+-------+----------+-------+------------+-------------+------------------+--------------+----------------------+
| Cell  | Keyspace | Shard | TabletType | State       | Alias            | Hostname     | MasterTermStartTime  |
+-------+----------+-------+------------+-------------+------------------+--------------+----------------------+
| zone1 | commerce | 0     | MASTER     | SERVING     | zone1-0000000100 | 7dc55e26e778 | 2021-01-27T12:50:58Z |
| zone1 | commerce | 0     | REPLICA    | NOT_SERVING | zone1-0000000101 | 7dc55e26e778 |                      |
| zone1 | commerce | 0     | RDONLY     | NOT_SERVING | zone1-0000000102 | 7dc55e26e778 |                      |
+-------+----------+-------+------------+-------------+------------------+--------------+----------------------+

vitess@7dc55e26e778:/vt/local$ vtctl -version
ERROR: logging before flag.Parse: E0127 13:13:48.186764    1908 syslogger.go:149] can't connect to syslog
Version: e259a08f0 (Git branch 'mariadb104_compatibility') built on Wed Jan 27 12:44:06 UTC 2021 by vitess@adc40b5d1fb0 using go1.15.6 linux/amd64

Looking further into draft PR https://github.com/vitessio/vitess/pull/7318

[shlomi-noach]

@askdba can you please illustrate the steps to reproduce? I want to look at the ApplySchema command you executed. How did you build and what did you run, exactly?

[askdba]

@shlomi-noach steps to build MariaDB 10.4

• Edit and add mariadb104 flavor to Makefile
• Edit and add mariadb104 to docker/base/Dockerfile
• Edit and add mariadb104 to docker/local/Dockerfile
• Create docker/bootstrap/Dockerfile.mariadb104 file (copy from mariadb103)

make docker_local run.sh using that hash that make generates.

I will create a draft PR so you can see my changes. I'm also testing suggestions from the draft PR #7318 suggestions around config/init_db.sql. I think there are changes needs for replication setup as well.

[mattlord]

I'm going to close this as won't fix for now given the deprecation notice in https://github.com/vitessio/vitess/issues/9518.