Preface

Percona is well known for its offer of several outstanding fully open source, free to download software packages. And while Percona started as a MySQL focus company, nowadays it covers different technologies such as MySQL, Postgres and Mongodb.

In its constant effort to make life easier for our utilizer Percona had moved from providing single software packages, to Percona Distributions for MySQL, MongoDB and Postgres. Percona Distributions are a set of software packages that Percona has tested and certifies working together. That it easier to deploy architectural solutions requiring the use of multiple components, such as proxy, topology manager, backup software and more. 

But we are going even further, and with the release of Percona Distribution for MySQL/MongoDB Operator we are providing a high level of automation to roll out and manage solutions based on Percona Distributions. 

One of my tasks, as MySQL technical leader, is to identify optimal architectures to serve several common cases. Such as Percona Distribution for MySQL: High Availability with Group Replication Solution. Or in the case of  Percona Distribution for MySQL Operator, identify the different dimensions (low/mid/high utilization) and suggest a Vanilla setup with the scope to get the most out of the solution deployed.  

This is a long exercise, which started with a lot of internal discussions to identify what can make sense as traffic, then testing, identifying the saturation points, testing again and so on. 

It is during this process that I found a small problem (Feature Request). This small issue is preventing us from easily and dynamically modifying some parameters in the checks the Operator  uses. Given that we had to put the testing on hold until the above FR is implemented. As you can see it is a small thing but it will give us better control over the Operator behavior and will help to have a well tuned platform. 

This article is to show the level of improvement you can have with small but targeted tuning.To do so I used the smallest solution we have identified. The solution is dimensioned to serve a small website or a simple application with low level of traffic. 

The environment

To help identify a balanced setup we were using sysbench and sysbench-tpcc. The whole stack on GCP was composed of Application nodes with sysbench, 2 ProxySQL nodes for R/W split only, 3 VMS 8 CPU 32GB RAM, with the Percona operator managing the MySQL service.

Tests

For this specific test we were running 68 - 96 -128 - 256 threads:

• Sysbench read only
• Sysbench read/write
• Sysbench Tpc-c like 

The tests were run multiple times and the data considered is the consolidation of the multiple runs. 

We always run first on basic environments for baseline. Meaning no tuning for the MySQL or Operator, just dimension correctly disk space and BufferPool (and related).

Then we apply some tuning and run the tests multiple times eventually refining when/where needed. 

The code can be found here and here

And now the results…

Sysbench r/w tests

I am not going to describe in detail the images that I think are clear enough. Just keep in mind on the left we have the results from our baseline, on the right the same tests on the same platform with the optimization applied.

Operations

Worth to mention that without tuning, the platform was not able to consistently scale up to 256 threads. While with a bit of adjustment not only it was able to serve 256 threads but we could have gone a bit further.

Reads

Writes

Comments

As you can see the sysbench tests clearly indicate that the platform with minor adjustment was acting better, and that it was able to serve more and with constant scaling. Let me add that almost all the tests runned on the “basic” platform had incidents, meaning as soon as the traffic was increasing, Sysbench was reporting connection interruptions or errors.

TPC-C

Operations

Reads

Writes

Comments

Also for Tpc-c like tests we have exactly the same trend. With our “optimised” solution able to serve up to 1516 qps while the “basic” one was able to reach only 322. In this case Also the “optimised” solution was not able to scale up to 256 threads, but that makes sense, given the more intense write workload present in this test and the small dimension of the platform.

Wooha what have you changed?

You may think we have done crazy things to get this difference, but we did not.

Let us jump back. As indicated at the beginning I had opened a FR (https://jira.percona.com/browse/K8SPXC-749) to be able to tune some/most of the timeouts existing in the operator.

Why? Think about this, when you install a cluster on iron, you do not set it to be able to work only when the load is low, and all the components of the server are able to answer in nanoseconds. What you do instead is tune the whole system to accommodate the increasing load, and you will give to some elements more space for “flexibility” eventually expecting to have delays in answer. When doing so you also need to correctly align all the parameters that will be affected on cascade. For instance if you know your data nodes will be very busy serving queries, they may also slow down in answering internal health checks, but if you relax the cluster health checks and not the checks used for testing the cluster from operator point of view, the platform will be unbalanced and will not work correctly.

At the same time, if you do not tune the solution at all, you may end up with a platform that is theoretically able to serve the load, but that is crashing for artificial limitations. 

The last one is exactly what was happening with our “basic” solution. As it is the operator comes with parameters that allow it to work well, but that are not designed to scale. Is like having a server where your CPUs are always at 20% and if the applications ask more, a controller will chop them in fear of having too much load. But the fact is that you want to have the CPUs at 80% or the server will be underutilized. 

Anyhow what we have changed was some Innodb parameters, to allow internal operations to work better. Then we force consistent reads in PXC, which actually SLOW down the operations, and finally we tune the PXC cluster to be more flexible in its internal checks, avoiding having it to expel nodes unless really needed to. 

All the above were done using the Operator configuration, but then we had to work manually changing all the timeouts parameters used by the operator checks to be aligned with what we had defined in the cluster. 

In particular what we have changed was:

script                      line    value
/usr/bin/clustercheckcron   33      TIMEOUT=10
liveness-check.sh           23      TIMEOUT=5
readiness-check.sh          21      TIMEOUT=10
/usr/local/bin/check_pxc.sh 15      TIMEOUT=${CUSTOM_TIMEOUT:-10}

Wait .. why ProxySQL?

Ok this is another long discussion and I will cover it better in another article. For now just consider that HAProxy does not allow r/w splitting or other nice functionalities like firewalling etcetera etcetera. So the idea is simple, let us use the operator with what fits it better, and then decouple the special needs, eventually adding proxysql in a separate deployment. 

If you are scared of the cost of adding an additional block to the architecture:

Where:
ProxySQL means: Application → ProxySQL → HAProxy.
HAProxy means: Application → HAProxy.

Hope this puts your worries at rest, of course this is using the “optimised” solution.

Conclusions

Percona Distribution for MySQL Operator, is a constantly growing/improving solution. It also has a lot of interesting features, like being able to manage your backup/restore, point in time recovery, and more. But its adoption is still limited and it is normal to have some drawbacks like this one. It is on us who play with real production environments, or as in this case playing to define certified solutions, to give feedback to improve how the operator works, in order to make it a stronger product able to serve you better day by day.

Now we are going to wait for the FR to be implemented, and then we will recover our dimensioning work. 

When organizing things helps to simplify life.

In the previous article we start to explore dynamic privileges and the interaction with the static ones. We also saw how to remove SUPER privilege from a DBA account. 

What we did was go by subtraction. But in real life, we should act differently. We should ADD only what is really needed for the account to work correctly.

Adding privilege one by one, and for each user is problematic given the level of interaction they may have, and also prone to mistakes. 

Instead we can use ROLES to group, assign and revoke the correct privileges in a much easier way.

This is becoming even more important in MySQL with the advent of dynamic privileges.

What should we do to correctly use ROLEs? Well first of all design.  

The first step is to identify the ROLES, in doing so we need to keep a basic principle, make it simple, as such let us try to avoid having too many ROLES, or ROLE with too many cross functional privileges.

My proposal: 

• DBA (The lord of the databases who can do all)
• MaintenanceAdmin (DBA minions :-) they can perform only some action on the server, and server only)
• UserAdmin (Can create users assign grants and so on)
• MonitorUser (See all process and read from performance_schema)
• DBManager (Can add/drop/modify schemas/tables/triggers/view/routines etc )
• DBDesigner (Can modify specific objects mostly with a clear identification by schema/table)
• ReplicationAdmin (Can add/change/remove start/stop replication also GR)
• BackupAdmin (Can take backup, cannot restore)

We have 8 administrative ROLES and they should cover ALL we need for administrative tasks.

Now let us create them:

CREATE ROLE 'DBA', 'MaintenanceAdmin', 'UserAdmin', 'MonitorUser', 'DBManager', 'DBDesigner', 'ReplicationAdmin', 'BackupAdmin'

DC2-1(root@localhost) [mysql]>Select user,host from mysql.user where account_locked ='Y' and password_expired='Y' order by 1;
+------------------+------+
| user             | host |
+------------------+------+
| BackupAdmin      | %    |
| DBA              | %    |
| DBDesigner       | %    |
| DBManager        | %    |
| MaintenanceAdmin | %    |
| MonitorUser      | %    |
| ReplicationAdmin | %    |
| UserAdmin        | %    |
+------------------+------+
8 rows in set (0.00 sec)

Let us check the roles one by one and see what privileges we need to assign.

Our test user do not have any grant:

DC2-2(secure_test@localhost) [(none)]>show grants for current_user()\G
*************************** 1. row ***************************
Grants for secure_test@localhost: GRANT USAGE ON *.* TO `secure_test`@`localhost`

DBA,

well you may say .. easy GRANT ALL.

Wrong! As already indicated in the previous article, doing that will also assign SUPER, which is deprecated from MySQL 8.0.x. Let us start with the right foot and add ONLY what we need:

GRANT SELECT, INSERT, UPDATE, DELETE, CREATE, DROP, RELOAD, SHUTDOWN, PROCESS, FILE, REFERENCES, INDEX, ALTER, SHOW DATABASES, CREATE TEMPORARY TABLES, LOCK TABLES, EXECUTE, REPLICATION SLAVE, REPLICATION CLIENT, CREATE VIEW, SHOW VIEW, CREATE ROUTINE, ALTER ROUTINE, CREATE USER, EVENT, TRIGGER, CREATE TABLESPACE, CREATE ROLE, DROP ROLE ON *.* TO `DBA`@`%` WITH GRANT OPTION;
   
GRANT APPLICATION_PASSWORD_ADMIN,AUDIT_ADMIN,BACKUP_ADMIN,BINLOG_ADMIN,BINLOG_ENCRYPTION_ADMIN,CLONE_ADMIN,CONNECTION_ADMIN,ENCRYPTION_KEY_ADMIN,FLUSH_OPTIMIZER_COSTS,FLUSH_STATUS,FLUSH_TABLES,FLUSH_USER_RESOURCES,GROUP_REPLICATION_ADMIN,INNODB_REDO_LOG_ARCHIVE,INNODB_REDO_LOG_ENABLE,PERSIST_RO_VARIABLES_ADMIN,REPLICATION_APPLIER,REPLICATION_SLAVE_ADMIN,RESOURCE_GROUP_ADMIN,RESOURCE_GROUP_USER,ROLE_ADMIN,SERVICE_CONNECTION_ADMIN,SESSION_VARIABLES_ADMIN,SET_USER_ID,SHOW_ROUTINE,SYSTEM_USER,SYSTEM_VARIABLES_ADMIN,TABLE_ENCRYPTION_ADMIN,XA_RECOVER_ADMIN ON *.* TO `DBA`@`%` WITH GRANT OPTION;

That should be exactly the same as GRANT ALL, but without SUPER. 

To assign the ROLE to our test user:

GRANT `DBA`@`%` TO `secure_test`@`localhost`

Now our user has:

DC2-2(secure_test@localhost) [(none)]>show grants for current_user()\G
*************************** 1. row ***************************
Grants for secure_test@localhost: GRANT USAGE ON *.* TO `secure_test`@`localhost`
*************************** 2. row ***************************
Grants for secure_test@localhost: GRANT `DBA`@`%` TO `secure_test`@`localhost`

Correct you now see DBA as grant but that is not active:

DC2-2(secure_test@localhost) [(none)]>show grants for DBA@'%'\G
ERROR 1142 (42000): SELECT command denied to user 'secure_test'@'localhost' for table 'user'

To ACTIVATE a role you need to do it explicitly:

 SET DEFAULT ROLE DBA TO  secure_test@'localhost';

And have the user reconnect!

Once a role is activated we can also use:

show grants for current_user()\G

To check which privileges are now active for a specific user.

We can also control which role is active for which user querying the table mysql.default_roles. 

To remove the active role:

SET DEFAULT ROLE NONE TO  secure_test@'localhost';

Anyhow, NOW we have our DBA role available for all DBA and if we need to change something we can do it just there on the ROLE and not on each single user. 

MaintenanceAdmin,

GRANT EVENT, LOCK TABLES, RELOAD, SELECT, SHOW DATABASES, RELOAD, SHUTDOWN ON *.* TO `MaintenanceAdmin`@`%`;
GRANT BINLOG_ADMIN, CONNECTION_ADMIN, ENCRYPTION_KEY_ADMIN, GROUP_REPLICATION_ADMIN, REPLICATION_SLAVE_ADMIN, SESSION_VARIABLES_ADMIN, SET_USER_ID, SYSTEM_VARIABLES_ADMIN ON *.* TO `MaintenanceAdmin`@`%`;
GRANT `MaintenanceAdmin`@`%` TO `secure_test`@`localhost` ;

UserAdmin,

GRANT CREATE USER, GRANT OPTION, RELOAD, SHOW DATABASES ON *.* TO `UserAdmin`@`%`;
GRANT ROLE_ADMIN  ON *.* TO `UserAdmin`@`%`;
GRANT `UserAdmin`@`%` TO `secure_test`@`localhost` ;

MonitorUser,

GRANT PROCESS, REPLICATION CLIENT ON *.* TO `MonitorUser`@`%`;
GRANT SELECT ON performance_schema.* TO `MonitorUser`@`%`;
GRANT `MonitorUser`@`%` TO `secure_test`@`localhost` ;

DBManager,

GRANT ALTER, ALTER ROUTINE, CREATE, CREATE ROUTINE, CREATE TABLESPACE, CREATE TEMPORARY TABLES, CREATE VIEW, DELETE, DROP, DROP ROLE, EVENT, INDEX, INSERT, LOCK TABLES, RELOAD, SELECT, SHOW DATABASES, SHOW VIEW, TRIGGER, UPDATE  ON *.* TO `DBManager`@`%`;
GRANT SET_USER_ID, SHOW_ROUTINE ON *.* TO `DBManager`@`%`;
GRANT `DBManager`@`%` TO `secure_test`@`localhost` ;

DBDesigner,

GRANT ALTER, ALTER ROUTINE, CREATE, CREATE ROUTINE, CREATE VIEW, INDEX, SELECT, SHOW DATABASES, SHOW VIEW, TRIGGER ON *.* TO `DBDesigner`@`%`;
GRANT `DBDesigner`@`%` TO `secure_test`@`localhost` ;

ReplicationAdmin,

GRANT REPLICATION CLIENT ON *.* TO `ReplicationAdmin`@`%`;
GRANT REPLICATION_APPLIER, REPLICATION_SLAVE_ADMIN, GROUP_REPLICATION_ADMIN, SERVICE_CONNECTION_ADMIN ON *.* TO `ReplicationAdmin`@`%`;
GRANT SELECT on performance_schema.* TO `ReplicationAdmin`@`%`;
GRANT SELECT on mysql.* TO `ReplicationAdmin`@`%`;
GRANT `ReplicationAdmin`@`%` TO `secure_test`@`localhost` ;

BackupAdmin,

GRANT EVENT, LOCK TABLES, SELECT, SHOW DATABASES ON *.* TO `BackupAdmin`@`%`;
GRANT BACKUP_ADMIN ON *.* TO `BackupAdmin`@`%`;
GRANT `BackupAdmin`@`%` TO `secure_test`@`localhost` ;

Once all our ROLES are in, we can test them. For instance we can check our ReplicationAdmin checking the Binary Logs and stopping/starting our Group Replication (or normal Replication):

DC2-2(secure_test@localhost) [(none)]>show binary logs;
ERROR 1227 (42000): Access denied; you need (at least one of) the SUPER, REPLICATION CLIENT privilege(s) for this operation

DC2-2(secure_test@localhost) [(none)]>stop group_replication;
ERROR 1227 (42000): Access denied; you need (at least one of) the SUPER or GROUP_REPLICATION_ADMIN privilege(s) for this operation

Also if created and assigned the role is not active. Let us now enable the role for the user:

SET DEFAULT ROLE ReplicationAdmin  TO  secure_test@'localhost';

Remember to reconnect!

DC2-2(secure_test@localhost) [(none)]>show binary logs;
+---------------+-----------+-----------+
| Log_name      | File_size | Encrypted |
+---------------+-----------+-----------+
| binlog.000011 | 113802321 | No        |
| binlog.000012 |     19278 | No        |
+---------------+-----------+-----------+
2 rows in set (0.00 sec)

DC2-2(secure_test@localhost) [(none)]>stop group_replication;
Query OK, 0 rows affected (5.25 sec)

DC2-2(secure_test@localhost) [(none)]>select * from  performance_schema.replication_group_members;
+---------------------------+--------------------------------------+-------------+-------------+--------------+-------------+----------------+
| CHANNEL_NAME              | MEMBER_ID                            | MEMBER_HOST | MEMBER_PORT | MEMBER_STATE | MEMBER_ROLE | MEMBER_VERSION |
+---------------------------+--------------------------------------+-------------+-------------+--------------+-------------+----------------+
| group_replication_applier | 7fddf04f-9797-11eb-a193-08002734ed50 | gr5         |        3306 | OFFLINE      |             |                |
+---------------------------+--------------------------------------+-------------+-------------+--------------+-------------+----------------+
1 row in set (0.00 sec)

DC2-2(secure_test@localhost) [(none)]>start group_replication;
Query OK, 0 rows affected (3.70 sec)

DC2-2(secure_test@localhost) [(none)]>select * from  performance_schema.replication_group_members;
+---------------------------+--------------------------------------+-------------+-------------+--------------+-------------+----------------+
| CHANNEL_NAME              | MEMBER_ID                            | MEMBER_HOST | MEMBER_PORT | MEMBER_STATE | MEMBER_ROLE | MEMBER_VERSION |
+---------------------------+--------------------------------------+-------------+-------------+--------------+-------------+----------------+
| group_replication_applier | 79ede65d-9797-11eb-9963-08002734ed50 | gr4         |        3306 | ONLINE       | PRIMARY     | 8.0.23         |
| group_replication_applier | 7e214802-9797-11eb-a0cf-08002734ed50 | gr6         |        3306 | ONLINE       | SECONDARY   | 8.0.23         |
| group_replication_applier | 7fddf04f-9797-11eb-a193-08002734ed50 | gr5         |        3306 | ONLINE       | SECONDARY   | 8.0.23         |
+---------------------------+--------------------------------------+-------------+-------------+--------------+-------------+----------------+
3 rows in set (0.01 sec)

And these are the privileges active:

DC2-2(secure_test@localhost) [(none)]>show grants for current_user()\G
*************************** 1. row ***************************
Grants for secure_test@localhost: GRANT REPLICATION CLIENT ON *.* TO `secure_test`@`localhost`
*************************** 2. row ***************************
Grants for secure_test@localhost: GRANT GROUP_REPLICATION_ADMIN,REPLICATION_APPLIER,REPLICATION_SLAVE_ADMIN,SERVICE_CONNECTION_ADMIN ON *.* TO `secure_test`@`localhost`
*************************** 3. row ***************************
Grants for secure_test@localhost: GRANT SELECT ON `mysql`.* TO `secure_test`@`localhost`
*************************** 4. row ***************************
Grants for secure_test@localhost: GRANT SELECT ON `performance_schema`.* TO `secure_test`@`localhost`
*************************** 5. row ***************************
Grants for secure_test@localhost: GRANT `BackupAdmin`@`%`,`DBA`@`%`,`DBDesigner`@`%`,`DBManager`@`%`,`MaintenanceAdmin`@`%`,`MonitorUser`@`%`,`ReplicationAdmin`@`%`,`UserAdmin`@`%` TO `secure_test`@`localhost`
5 rows in set (0.00 sec)

Conclusions

Using the ROLES allows us to modify the needed privileges in one place, and at the same time will allow us to keep under control the possible proliferation of dynamic privileges due the use of components or plugins, significantly reducing the complexity of having multiple privileges sources.

Roles are normally used in the most common Databases and MySQL had implemented them quite late. But using roles is the natural evolution of how we should deal with user grants when moving from small platforms to medium/large. 

The time when we assign single user privileges IS GONE, welcome to 2021 MySQLlers!

For your convenience I am distributing a simple SQL file with all commands to create the Roles as described in this article(link to github)

References

https://dev.mysql.com/doc/refman/8.0/en/roles.html

https://lefred.be/content/some-queries-related-to-mysql-roles/

https://lefred.be/content/mysql-8-0-listing-roles/

https://lefred.be/content/mysql-8-0-roles-and-graphml/

I was working on a Security Threat Tool script, when I had to learn more about the interaction between static and dynamic privileges in MySQL 8.

Dynamic privileges is a “new” thing added in MySQL 8 to easily extend the privileges definition, and at the same time to provide more granularity. For instance the FLUSH operation now has dedicated Privileges and by scope. 

Dynamic privileges are assigned at runtime. Most of them are active when the server starts. But they can also change in respect to the components or plugin when activated. (https://dev.mysql.com/doc/mysql-security-excerpt/8.0/en/privileges-provided.html#privileges-provided-dynamic)

Static privileges are the classical privileges available in MySQL (https://dev.mysql.com/doc/mysql-security-excerpt/8.0/en/privileges-provided.html#privileges-provided-static)

Those are built into the server and cannot be changed.

So far all is good. If we can give more flexibility to the security mechanism existing in MySQL, well I am all for it.

My first step was to deal with the abuse of SUPER. 

About that the manual comes to help with a section: Migrating Accounts from SUPER to Dynamic Privileges (https://dev.mysql.com/doc/mysql-security-excerpt/8.0/en/privileges-provided.html#dynamic-privileges-migration-from-super) . 

Woo perfect!

Let us play a bit. First let me create a user:

create user secure_test@'localhost' identified by 'secret';
DC2-2(secure_test@localhost) [(none)]>show grants for current_user();
+-------------------------------------------------+
| Grants for secure_test@localhost                |
+-------------------------------------------------+
| GRANT USAGE ON *.* TO `secure_test`@`localhost` |
+-------------------------------------------------+

As you can see I can connect, but have no permissions.

On another terminal with an administrative account, let us do the classical operation to create a DBA:

GRANT ALL on *.* to secure_test@'localhost' WITH GRANT OPTION;

And now I have :

DC2-2(secure_test@localhost) [(none)]>show grants for current_user()\G
*************************** 1. row ***************************
Grants for secure_test@localhost: GRANT SELECT, INSERT, UPDATE, DELETE, CREATE, DROP, RELOAD, SHUTDOWN, PROCESS, FILE, REFERENCES, INDEX, ALTER, SHOW DATABASES, SUPER, CREATE TEMPORARY TABLES, LOCK TABLES, EXECUTE, REPLICATION SLAVE, REPLICATION CLIENT, CREATE VIEW, SHOW VIEW, CREATE ROUTINE, ALTER ROUTINE, CREATE USER, EVENT, TRIGGER, CREATE TABLESPACE, CREATE ROLE, DROP ROLE ON *.* TO `secure_test`@`localhost` WITH GRANT OPTION
*************************** 2. row ***************************
Grants for secure_test@localhost: GRANT APPLICATION_PASSWORD_ADMIN,AUDIT_ADMIN,BACKUP_ADMIN,BINLOG_ADMIN,BINLOG_ENCRYPTION_ADMIN,CLONE_ADMIN,CONNECTION_ADMIN,ENCRYPTION_KEY_ADMIN,FLUSH_OPTIMIZER_COSTS,FLUSH_STATUS,FLUSH_TABLES,FLUSH_USER_RESOURCES,GROUP_REPLICATION_ADMIN,INNODB_REDO_LOG_ARCHIVE,INNODB_REDO_LOG_ENABLE,PERSIST_RO_VARIABLES_ADMIN,REPLICATION_APPLIER,REPLICATION_SLAVE_ADMIN,RESOURCE_GROUP_ADMIN,RESOURCE_GROUP_USER,ROLE_ADMIN,SERVICE_CONNECTION_ADMIN,SESSION_VARIABLES_ADMIN,SET_USER_ID,SHOW_ROUTINE,SYSTEM_USER,SYSTEM_VARIABLES_ADMIN,TABLE_ENCRYPTION_ADMIN,XA_RECOVER_ADMIN ON *.* TO `secure_test`@`localhost` WITH GRANT OPTION

As you can see I have a bunch of Privileges assigned. 

To be honest, to have to identify exactly what each privilege does and how it interacts with the others is challenging.

Anyhow, the manual tell us:

"For each account identified by the preceding query, determine the operations for which it needs SUPER. Then grant the dynamic privileges corresponding to those operations, and revoke SUPER."

In our case:

revoke SUPER on *.* from secure_test@'localhost';

Which will remove the SUPER privileges, but what else will remain active? 

Let us try one of the easiest things, let us modify the variable super_read_only.

With super I can change the value of the variable without problems , but if I remove the SUPER privileges, what will happen? 

DC2-2(secure_test@localhost) [(none)]>show grants for current_user()\G
*************************** 1. row ***************************
Grants for secure_test@localhost: GRANT SELECT, INSERT, UPDATE, DELETE, CREATE, DROP, RELOAD, SHUTDOWN, PROCESS, FILE, REFERENCES, INDEX, ALTER, SHOW DATABASES, CREATE TEMPORARY TABLES, LOCK TABLES, EXECUTE, REPLICATION SLAVE, REPLICATION CLIENT, CREATE VIEW, SHOW VIEW, CREATE ROUTINE, ALTER ROUTINE, CREATE USER, EVENT, TRIGGER, CREATE TABLESPACE, CREATE ROLE, DROP ROLE ON *.* TO `secure_test`@`localhost` WITH GRANT OPTION
*************************** 2. row ***************************
Grants for secure_test@localhost: GRANT APPLICATION_PASSWORD_ADMIN,AUDIT_ADMIN,BACKUP_ADMIN,BINLOG_ADMIN,BINLOG_ENCRYPTION_ADMIN,CLONE_ADMIN,CONNECTION_ADMIN,ENCRYPTION_KEY_ADMIN,FLUSH_OPTIMIZER_COSTS,FLUSH_STATUS,FLUSH_TABLES,FLUSH_USER_RESOURCES,GROUP_REPLICATION_ADMIN,INNODB_REDO_LOG_ARCHIVE,INNODB_REDO_LOG_ENABLE,PERSIST_RO_VARIABLES_ADMIN,REPLICATION_APPLIER,REPLICATION_SLAVE_ADMIN,RESOURCE_GROUP_ADMIN,RESOURCE_GROUP_USER,ROLE_ADMIN,SERVICE_CONNECTION_ADMIN,SESSION_VARIABLES_ADMIN,SET_USER_ID,SHOW_ROUTINE,SYSTEM_USER,SYSTEM_VARIABLES_ADMIN,TABLE_ENCRYPTION_ADMIN,XA_RECOVER_ADMIN ON *.* TO `secure_test`@`localhost` WITH GRANT OPTION

As you can see SUPER is gone. 

DC2-2(secure_test@localhost) [(none)]>set global super_read_only=0;
Query OK, 0 rows affected (0.00 sec)

And I can still modify the global variable. WHY?  

The manual says that SYSTEM_VARIABLES_ADMIN from the dynamic privileges allow us to modify "Enables system variable changes at runtime". Well what if I revoke it? 

revoke SYSTEM_VARIABLES_ADMIN on *.* from  secure_test@'localhost';

DC2-2(secure_test@localhost) [(none)]>set global super_read_only=0;
ERROR 1227 (42000): Access denied; you need (at least one of) the SUPER or SYSTEM_VARIABLES_ADMIN privilege(s) for this operation

Great! So in order to really remove/limit super I need to also remove SYSTEM_VARIABLES_ADMIN. But is that all?

Well to make it short, no it is not. 

Checking the manual you can see that SUPER is affecting all these:

• BINLOG_ADMIN,
• CONNECTION_ADMIN,
• ENCRYPTION_KEY_ADMIN,
• GROUP_REPLICATION_ADMIN,
• REPLICATION_SLAVE_ADMIN,
• SESSION_VARIABLES_ADMIN,
• SET_USER_ID,
• SYSTEM_VARIABLES_ADMIN

And these are the ones by default. But we can also have others depending on the plugins we have active. 

So in theory to be sure we are removing all SUPER related privileges, we should:

REVOKE SUPER, BINLOG_ADMIN, CONNECTION_ADMIN, ENCRYPTION_KEY_ADMIN, GROUP_REPLICATION_ADMIN, REPLICATION_SLAVE_ADMIN, SESSION_VARIABLES_ADMIN, SET_USER_ID, SYSTEM_VARIABLES_ADMIN on *.* from secure_test@'localhost';

This, should leave us with the equivalent of a user without SUPER:

DC2-2(secure_test@localhost) [(none)]>show grants for current_user()\G
*************************** 1. row ***************************
Grants for secure_test@localhost: GRANT SELECT, INSERT, UPDATE, DELETE, CREATE, DROP, RELOAD, SHUTDOWN, PROCESS, FILE, REFERENCES, INDEX, ALTER, SHOW DATABASES, CREATE TEMPORARY TABLES, LOCK TABLES, EXECUTE, REPLICATION SLAVE, REPLICATION CLIENT, CREATE VIEW, SHOW VIEW, CREATE ROUTINE, ALTER ROUTINE, CREATE USER, EVENT, TRIGGER, CREATE TABLESPACE, CREATE ROLE, DROP ROLE ON *.* TO `secure_test`@`localhost` WITH GRANT OPTION
*************************** 2. row ***************************
Grants for secure_test@localhost: GRANT APPLICATION_PASSWORD_ADMIN,AUDIT_ADMIN,BACKUP_ADMIN,BINLOG_ENCRYPTION_ADMIN,CLONE_ADMIN,FLUSH_OPTIMIZER_COSTS,FLUSH_STATUS,FLUSH_TABLES,FLUSH_USER_RESOURCES,INNODB_REDO_LOG_ARCHIVE,INNODB_REDO_LOG_ENABLE,PERSIST_RO_VARIABLES_ADMIN,REPLICATION_APPLIER,RESOURCE_GROUP_ADMIN,RESOURCE_GROUP_USER,ROLE_ADMIN,SERVICE_CONNECTION_ADMIN,SHOW_ROUTINE,SYSTEM_USER,TABLE_ENCRYPTION_ADMIN,XA_RECOVER_ADMIN ON *.* TO `secure_test`@`localhost` WITH GRANT OPTION

CONCLUSIONS

In this first blog we have started to explore the usage of Dynamic privileges, and what we need to do to remove the SUPER privilege. 

Nevertheless, the list above is still a bit chaotic and unsafe. We still have SHUTDOWN or RELOAD or FILE, all of them are insecure and should be assigned with great care. In the next article we will see how to deal with Dynamic and Static privileges by Role and we also try to have clearer how they affect one another.

Percona live is over, and we finally get some feedback about our presentations.

Initially I had 3 presentations to give:

• Comparing High Available Solutions With Percona XtraDB Cluster and Percona Server With Group Replication.
• Comparing Hash Join solution, the good, the bad and the worse. The New version 2021.
• Boosting MySQL NDB cluster & MySQL Innodb Cluster with PrxySQL V2

But when I saw we were having a lot of great submissions, I decided that it would be better for the conference and for Percona to drop 2 of them and leave some free slots for others.

That has always been my line of conduct, I do not think we should have speakers with multiple talks unless exceptions.  I know in the past I had been presenting multiple times, but that is why I am stating this now, more and more.

Anyhow, the remaining talk was Comparing High Available Solutions With Percona XtraDB Cluster and Percona Server With Group Replication. Which is a high level discussion about High Availability and the two main solutions Percona provides for it. 

The presentation was previously recorded and played during the event. This allowed me to interact during the presentation much more than if I had to do it live.

I thought we had a good level of interactions and discussion which is always a good sign, but when we finally got the feedback I discovered my session had 260 attendees.  

Now, I am still trying to get more info (wondering why it is so difficult to get) but from what I discovered so far, it was in the first three most attended. 

Given that I want to THANK YOU to all who have been there. I want to say one million times THANK YOU to all the ones who had also interacted during the presentation.

The reason to be for a speaker is to have not only people in the room, but people who interact because they are interested.
I like to think this is the result of years of honest and unbias blogging and speaking. So once more thank you! 

Percona had not publish it yet on the official site, I am sharing it from youtube. In case you are still interested to view it, unfortunately the chat interaction is not there, given this was my original recording I had passed for the conference, but better than nothing right?

And now few comments about the conference. 

In general it was a good conference, I think we had a decent mix of technical and less technical content. I really enjoyed the key notes with Amanda Brock and after Luis Villa. I can be more in alignment with one instead of the other, but the topic and the side discussion in the chat was great.

About trying to follow the tracks and trying to attend the most interesting speeches (for me), I have to say I was a bit disappointed.

In my article here I was giving an indication of which presentations I was going to attend or when in conflict I was expecting to be able to see the recording. 

But there had been some unexpected inconveniences. 

The first one, positive, was that I wanted to attend more talks than the ones in the list. The second one, negative, was that the conference organization did not provide the recording after the speech. Actually as mentioned above most of them are still not published.

Now, while I understand that in case of LIVE talk, you may need some time to put them up, I do not get why we were not publishing the recording, as they were, after the official slot was over. Any additional refining or editing could have been done later, but in the meantime people would have been able to get better service and attend more.

Point was that as soon as I discovered it was not possible to watch the recording after the presentation, I started to keep on at least two screens, and record what I cannot focus on to be able to watch it later. Very annoying and disappointing. But hey space for improvement right? Next online event can be better. 

Another thing I liked was the platform used for the conference, easy, clean and allowed a lot of “offline” sharing. Yes, sometimes we had to reload the page to have the presentation running, but that was not a big deal.

I want to mention again the great work done by the Percona marketing team in making this event a great success. All of them, but special mention is for Bronwyn Campbell and Valentina Lago, without them Percona live 2021 would NOT be what it was.

Finally, while all of us around the globe HOPE to be able to attend the next conference in person, I strongly doubt this will be possible. We MUST keep in mind conferences as Percona Live is a global event. That will make it very unlikely to have people attending in person soon. Obviously the option is to limit it to a regional event, which for me will mean to diminish its relevance in a very impactful way. I miss meeting in person, but I would prefer to have the conference online, if that means I will miss a huge part of the speakers and their content!

And I may be pessimistic, but I doubt we will be in a safe position before the next event. 

Well that is all for now, but stay tuned… because the two missed presentations are coming ;) 

To all THANK YOU two hundred sixty thousand times once more.