Deploy HTAP with MariaDB Enterprise ColumnStore 5 on Ubuntu 20.04 LTS

These instructions detail the deployment of MariaDB Enterprise ColumnStore 5 with MariaDB Enterprise Server 10.5 on Ubuntu 20.04 LTS in a HTAP Deployment configuration.

These instructions detail how to deploy a Hybrid Transactional/Analytical Processing (HTAP) solution, which is suited for a combined transactional and analytical workload.

MariaDB Enterprise Components

These instructions detail the deployment of the following MariaDB Enterprise components:

Component

Description

MariaDB Enterprise Server 10.5

  • A 100% Open Source modern SQL database.

MariaDB Enterprise ColumnStore 5

  • A columnar storage engine for MariaDB Enterprise Server that provides distributed, columnar storage for scalable analytical processing and smart transactions (HTAP).

MariaDB Enterprise Server Components

These instructions detail the deployment of the following MariaDB Enterprise Server components:

Component

Description

ColumnStore

  • It is a columnar storage engine that provides distributed, columnar storage for scalable analytical processing and smart transactions.

  • It is the analytical component of MariaDB's single stack Hybrid Transactional/Analytical Processing (HTAP) solution.

  • It is available as a plugin in MariaDB Enterprise Server 10.5.

InnoDB

MariaDB Replication

  • It allows data to be replicated from a primary server to one or more replica servers.

  • It supports asynchronous and semi-synchronous replication.

Term Definitions

Term

Definition

Columnar Database

  • A database where the columns of each row are stored separately.

  • Best suited for analytical and OLAP workloads.

  • Also known as a "column-oriented database".

Row Database

  • A database where all columns of each row are stored together.

  • Best suited for transactional and OLTP workloads.

  • Also known as a "row-oriented database".

System Preparation

Systems hosting Enterprise ColumnStore deployments require additional configuration prior to installation:

  1. Optimize Linux kernel parameters.

  2. Configure the Linux security module to support installation.

  3. Configure the character encoding.

  4. Optionally configure S3-compatible storage.

Optimize Linux Kernel Parameters

MariaDB Enterprise ColumnStore performs best when certain Linux kernel parameters are optimized.

  1. Set the relevant kernel parameters in a sysctl configuration file. For proper change management, we recommend setting them in an Enterprise ColumnStore-specific configuration file.

    For example, create a /etc/sysctl.d/90-mariadb-enterprise-columnstore.conf file with the following contents:

    # minimize swapping
    vm.swappiness = 1
    
    # Increase the TCP max buffer size
    net.core.rmem_max = 16777216
    net.core.wmem_max = 16777216
    
    # Increase the TCP buffer limits
    # min, default, and max number of bytes to use
    net.ipv4.tcp_rmem = 4096 87380 16777216
    net.ipv4.tcp_wmem = 4096 65536 16777216
    
    # don't cache ssthresh from previous connection
    net.ipv4.tcp_no_metrics_save = 1
    
    # for 1 GigE, increase this to 2500
    # for 10 GigE, increase this to 30000
    net.core.netdev_max_backlog = 2500
    
  2. Set the same kernel parameters at runtime using the sysctl command:

    $ sudo sysctl --load=/etc/sysctl.d/90-mariadb-enterprise-columnstore.conf
    

LSM Configuration for Install

To avoid confusion and potential problems, we recommend configuring the system's Linux Security Module (LSM) during installation. The specific steps to configure the security module will depend on the platform.

In the Configure the Linux Security Module section, we will configure the security module and restart it.

AppArmor (Debian/Ubuntu/SLES)

AppArmor must be disabled before installing MariaDB Enterprise ColumnStore.

  1. Disable AppArmor:

    $ sudo systemctl disable apparmor
    
  2. Reboot the system.

  3. Confirm that no AppArmor profiles are loaded using aa-status:

    $ sudo aa-status
    

    Example output:

    apparmor module is loaded.
    0 profiles are loaded.
    0 profiles are in enforce mode.
    0 profiles are in complain mode.
    0 processes have profiles defined.
    0 processes are in enforce mode.
    0 processes are in complain mode.
    0 processes are unconfined but have a profile defined.
    

Note

Remember to configure and re-enable AppArmor after the installation is complete.

Configure the Character Encoding

When using MariaDB Enterprise ColumnStore, it is recommended to set the system's locale to UTF-8.

  1. Set the system's locale to en_US.UTF-8 by executing localedef:

    $ sudo localedef -i en_US -f UTF-8 en_US.UTF-8
    

S3-Compatible Storage

MariaDB Enterprise ColumnStore can use S3-compatible storage to store its data. However, this functionality is optional.

We would recommend S3-compatible storage for all Enterprise ColumnStore users, because it can provide many benefits:

  • Secure: Most S3-compatible storage is encrypted-at-rest.

  • Scalable: Most S3-compatible storage is highly optimized for read and write scaling.

  • Resilient: Most S3-compatible storage is very low maintenance and highly available, since it relies on resilient cloud infrastructure.

  • Economical: Most S3-compatible storage is very inexpensive.

When S3-compatible storage is used, Enterprise ColumnStore caches data locally to improve performance.

Create an S3 Bucket

If you want to use S3-compatible storage, it is important to create the S3 bucket before you start ColumnStore.

If you already have an S3 bucket, confirm that the bucket is empty.

We will configure Enterprise ColumnStore to use the S3 bucket later in the Configure the S3 Storage Manager section.

Note

The specific steps to create the S3 bucket will depend on what S3-compatible storage you are using.

Enterprise ColumnStore Installation

MariaDB Corporation provides a APT package repository for Ubuntu 20.04 LTS.

MariaDB Enterprise ColumnStore ships as a storage engine plugin for MariaDB Enterprise Server and a platform engine to handle back-end storage processes. MariaDB Enterprise Server 10.5 does not require any additional software to operate as a single-node analytics database.

Install Enterprise ColumnStore Debian/Ubuntu (APT)

  1. Retrieve your Customer Download Token at https://customers.mariadb.com/downloads/token/ and substitute for CUSTOMER_DOWNLOAD_TOKEN in the following directions.

  2. Configure the APT package repository.

    MariaDB Enterprise ColumnStore 5 is available on MariaDB Enterprise Server 10.5.

    To configure APT package repositories:

    $ sudo apt install wget
    
    $ wget https://dlm.mariadb.com/enterprise-release-helpers/mariadb_es_repo_setup
    
    $ echo "b741361ea3a0a9fcaa30888a63ff3a8a4021882f126cf4ef26cf616493a29315  mariadb_es_repo_setup" \
        | sha256sum -c -
    
    $ chmod +x mariadb_es_repo_setup
    
    $ sudo ./mariadb_es_repo_setup --token="CUSTOMER_DOWNLOAD_TOKEN" --apply \
       --mariadb-server-version="10.5"
    
    $ sudo apt update
    
  3. Install some additional dependencies for Enterprise ColumnStore.

    On Debian 10 and Ubuntu 20.04, install the following:

    $ sudo apt install libjemalloc2
    
  4. Install MariaDB Enterprise ColumnStore and package dependencies:

    $ sudo apt install mariadb-server mariadb-backup \
       libmariadb3 mariadb-client \
       mariadb-plugin-columnstore
    
  5. Configure MariaDB Enterprise ColumnStore.

    Installation only loads MariaDB Enterprise ColumnStore to the system. MariaDB Enterprise ColumnStore requires configuration and additional post-installation steps before the database server is ready for use.

Enterprise ColumnStore Configuration

MariaDB Enterprise ColumnStore requires configuration after it is installed. The configuration file location depends on your operating system.

Enterprise Server Configuration

MariaDB Enterprise Server can be configured in the following ways:

  • System variables and options can be set in a configuration file (such as /etc/my.cnf). MariaDB Enterprise Server must be restarted to apply changes made to the configuration file.

  • System variables and options can be set on the command-line.

  • If a system variable supports dynamic changes, then it can be set on-the-fly using the SET statement.

Configuration Files

MariaDB's packages include several bundled configuration files. It is also possible to create custom configuration files.

On Debian and Ubuntu, MariaDB's packages bundle the following configuration files:

  • /etc/mysql/my.cnf

  • /etc/mysql/mariadb.cnf

  • /etc/mysql/mariadb.conf.d/50-client.cnf

  • /etc/mysql/mariadb.conf.d/50-mysql-clients.cnf

  • /etc/mysql/mariadb.conf.d/50-mysqld_safe.cnf

  • /etc/mysql/mariadb.conf.d/50-server.cnf

  • /etc/mysql/mariadb.conf.d/60-galera.cnf

  • /etc/mysql/mariadb.conf.d/mariadb-enterprise.cnf

And on Debian and Ubuntu, custom configuration files from the following directories are read by default:

  • /etc/mysql/conf.d/

  • /etc/mysql/mariadb.conf.d/

Configuring MariaDB for Enterprise ColumnStore

  1. Determine which system variables and options you need to configure.

    Mandatory system variables and options for HTAP include:

    System Variable/Option

    Description

    character_set_server

    Set this system variable to utf8

    collation_server

    Set this system variable to utf8_general_ci

    columnstore_use_import_for_batchinsert

    Set this system variable to ALWAYS to always use cpimport for LOAD DATA INFILE and INSERT...SELECT statements.

    server_id

    Sets the numeric Server ID for this MariaDB Enterprise Server. Must be unique in the deployment.

    log_bin

    Set this option to enable the Binary Log.

    binlog_format

    Set this to STATEMENT for HTAP.

    log_slave_updates

    Set this to OFF for HTAP.

    replicate_same_server_id

    Set this to ON for HTAP.

    binlog_do_db

    Set this to the name of the database that you want to replicate from InnoDB to ColumnStore.

    replicate_rewrite_db

    Set this to the names of the InnoDB and ColumnStore databases in the format <innodb database>-><columnstore database>.

    replicate_wild_do_table

    Set this to a pattern that matches the table names that you want to replicate from InnoDB to ColumnStore.

    Useful system variables and options for MariaDB Enterprise Server include:

    System Variable/Option

    Description

    innodb_buffer_pool_size

    Defines the amount of memory InnoDB reserves for the Buffer Pool. Set to no more than 16% of total memory on Servers that also run MariaDB ColumnStore.

    Useful system variables and options for HTAP include:

    System Variable/Option

    Description

    relay_log

    Sets the location for the Relay Log.

  2. Choose a configuration file in which to configure your system variables and options.

    We recommend not making custom changes to one of the bundled configuration files. Instead, create a custom configuration file in one of the included directories. Configuration files in included directories are read in alphabetical order. If you want your custom configuration file to override the bundled configuration files, it is a good idea to prefix the custom configuration file's name with a string that will be sorted last, such as z-.

    • On Debian and Ubuntu, a good custom configuration file would be: /etc/mysql/mariadb.conf.d/z-custom-my.cnf

  3. Set your system variables and options in the configuration file.

    They need to be set in a group that will be read by mariadbd, such as [mariadb] or [server].

    For example:

    [mariadb]
    log_error                              = mariadbd.err
    character_set_server                   = utf8
    collation_server                       = utf8_general_ci
    columnstore_use_import_for_batchinsert = ALWAYS
    
    # Replication Configuration (HTAP Server)
    server_id         = 1
    log_bin           = mariadb-bin
    binlog_format     = STATEMENT
    log_slave_updates = OFF
    columnstore_replication_slave    = ON
    
    # HTAP filtering rules
    
    # 1. The transactions are being
    #  replicated from itself
    replicate_same_server_id         = ON
    
    # 2. Only write queries that touch
    #   innodb_db to the binary log
    binlog_do_db            = innodb_db
    
    # 3. Rewrite innodb_db to columnstore_db
    #   prior to applying transaction
    replicate_rewrite_db    = innodb_db->columnstore_db
    
    # 4. Only replicate tables that begin with "htap"
    replicate_wild_do_table = columnstore_db.htap%
    

Configure Cross Engine Joins

When a cross engine join is executed, the ExeMgr process connects to the server using the root user with no password by default. MariaDB Enterprise Server 10.5 will reject this login attempt by default. If you plan to use Cross Engine Joins, you need to configure Enterprise ColumnStore to use a different user account and password. These directions are for configuring the cross engine join user. Directions for creating the cross engine join user are in the Create the Cross Engine Join User section.

To configure cross engine joins, perform the following steps, use the mcsSetConfig command.

For example, to configure Enterprise ColumnStore to use the cross_engine user account to connect to the server at 127.0.0.1:

$ sudo mcsSetConfig CrossEngineSupport Host 127.0.0.1
$ sudo mcsSetConfig CrossEngineSupport Port 3306
$ sudo mcsSetConfig CrossEngineSupport User cross_engine
$ sudo mcsSetConfig CrossEngineSupport Password cross_engine_passwd

Choose a password that meets your organization's password policies. If your MariaDB Enterprise Server instance has a password validation plugin installed, then the password should also meet the configured requirements.

By default, MariaDB Enterprise Server installs the simple_password_check plugin. Its requirements are configured by the simple_password_check_digits, simple_password_check_letters_same_case, simple_password_check_minimal_length, and simple_password_check_other_characters system variables.

Configure the S3 Storage Manager

MariaDB Enterprise ColumnStore can use S3-compatible storage, but it is not required. S3-compatible storage must be configured before it can be used.

To configure Enterprise ColumnStore to use S3-compatible storage, edit /etc/columnstore/storagemanager.cnf:

[ObjectStorage]

service = S3

[S3]
bucket = your_columnstore_bucket_name
endpoint = your_s3_endpoint
aws_access_key_id = your_s3_access_key_id
aws_secret_access_key = your_s3_secret_key
# iam_role_name = your_iam_role
# sts_region = your_sts_region
# sts_endpoint = your_sts_endpoint
# ec2_iam_mode=enabled

[Cache]
cache_size = your_local_cache_size
path = your_local_cache_path
  • The default local cache size is 2 GB.

  • The default local cache path is /var/lib/columnstore/storagemanager/cache.

  • Ensure that the local cache path has sufficient store space to store the local cache.

  • The bucket option must be set to the name of the bucket that you created in the Create an S3 Bucket step.

  • To use a specific IAM role, you must uncomment and set iam_role_name, sts_region, and sts_endpoint.

  • To use the IAM role assigned to an EC2 instance, you must uncomment ec2_iam_mode=enabled.

Start the Enterprise ColumnStore Processes

The Enterprise Server and Enterprise ColumnStore processes can be started using the systemctl command. In case the processes were started during the installation process, use the restart command to ensure that the processes pick up the new configuration. Perform the following procedure.

  1. Start the MariaDB Enterprise Server process and configure it to start automatically:

    $ sudo systemctl restart mariadb
    $ sudo systemctl enable mariadb
    
  2. Start the MariaDB Enterprise ColumnStore processes and configure them to start automatically:

    $ sudo systemctl restart mariadb-columnstore
    $ sudo systemctl enable mariadb-columnstore
    

Create User Accounts

For HTAP deployments, a couple user accounts need to be created.

Create the Cross Engine Join User

The credentials for cross engine joins were previously configured in the Cross Engine Joins section. The user account must also be created and granted the necessary privileges to access data.

  1. Connect to the server using MariaDB Client using the root@localhost user account:

    $ sudo mariadb
    
  2. Create the user account with the CREATE USER statement:

    CREATE USER 'cross_engine'@'127.0.0.1'
       IDENTIFIED BY "cross_engine_passwd";
    
    CREATE USER 'cross_engine'@'localhost'
       IDENTIFIED BY "cross_engine_passwd";
    

    Note

    Choose the same user name and password that was configured in the Cross Engine Joins section.

  3. Grant the user account SELECT privileges on all databases with the GRANT statement:

    GRANT SELECT, PROCESS ON *.*
       TO 'cross_engine'@'127.0.0.1';
    
    GRANT SELECT, PROCESS ON *.*
       TO 'cross_engine'@'localhost';
    

Create the Replication User

The deployment requires MariaDB Replication, so the replication user account must be created, and the user account must be granted sufficient privileges to perform replication.

  1. Connect to the server using MariaDB Client using the root@localhost user account:

    $ sudo mariadb
    
  2. Create the user account with the CREATE USER statement:

    CREATE USER 'htap_replication'@'localhost'
       IDENTIFIED BY 'passwd';
    

    Note

    Please choose a password that meets your organization's password policies. If your MariaDB Enterprise Server instance has a password validation plugin installed, then the password should also meet the configured requirements.

    By default, MariaDB Enterprise Server installs the simple_password_check plugin. Its requirements are configured by the simple_password_check_digits, simple_password_check_letters_same_case, simple_password_check_minimal_length, and simple_password_check_other_characters system variables.

  3. Grant the user account several global privileges with the GRANT statement.

    The required permissions depend on the version of MariaDB Enterprise Server that is being used.

    In ES 10.5.8-5 and later, the following privileges are required:

    GRANT REPLICA MONITOR, REPLICATION REPLICA,
    ON *.* TO 'htap_replication'@'localhost';
    

    In ES 10.5.6-4 and before, the following privileges are required:

    GRANT BINLOG MONITOR, REPLICATION REPLICA
    ON *.* TO 'htap_replication'@'localhost';
    
  4. This user account will be used to configure replication in the Configure MariaDB Replication section.

Configure MariaDB Replication

The deployment requires MariaDB Replication, which must be configured.

  1. Connect to the server using MariaDB Client using the root@localhost user account:

    $ sudo mariadb
    
  2. Set the GTID position by setting the gtid_slave_pos system variable.

    If this is a new deployment, then it would be set to the empty string:

    SET GLOBAL gtid_slave_pos='';
    
  3. Use the CHANGE MASTER TO statement to configure the server to replicate from itself starting from this position:

    CHANGE MASTER TO
       MASTER_HOST='localhost',
       MASTER_USER='htap_replication',
       MASTER_PASSWORD='passwd',
       MASTER_USE_GTID=slave_pos;
    
  4. Start replication using the START REPLICA statement:

    START REPLICA;
    
  5. Confirm that replication is working properly using the SHOW REPLICA STATUS statement:

    SHOW REPLICA STATUS;
    

Configure the Linux Security Module

If you stopped the Linux Security Module (LSM) during installation, you can restart the module and configure.

The specific steps to configure the security module depend on the platform.

Configure AppArmor (Debian/Ubuntu/SLES)

We disabled AppArmor in the AppArmor section, but we have to create an AppArmor profile for Enterprise ColumnStore before re-enabling it. This will ensure that AppArmor does not interfere with Enterprise ColumnStore's functionality.

For information on how to create a profile, see How to create an AppArmor Profile on ubuntu.com.

Administration

Enterprise ColumnStore has several components. Each of those components needs to be administered.

Enterprise Server Administration

MariaDB Enterprise Server uses systemctl to start and stop the server processes:

Operation

Command

Start

sudo systemctl start mariadb

Stop

sudo systemctl stop mariadb

Restart

sudo systemctl restart mariadb

Enable during startup

sudo systemctl enable mariadb

Disable during startup

sudo systemctl disable mariadb

Status

sudo systemctl status mariadb

Enterprise ColumnStore Administration

MariaDB Enterprise ColumnStore uses systemctl to start and stop the ColumnStore processes:

Operation

Command

Start

sudo systemctl start mariadb-columnstore

Stop

sudo systemctl stop mariadb-columnstore

Restart

sudo systemctl restart mariadb-columnstore

Enable during startup

sudo systemctl enable mariadb-columnstore

Disable during startup

sudo systemctl disable mariadb-columnstore

Status

sudo systemctl status mariadb-columnstore

Testing

When you have MariaDB Enterprise ColumnStore up and running, you should test it to ensure that it is in working order and that there were not any issues during startup.

Using HTAP Replication

  1. Connect to the server using MariaDB Client using the root@localhost user account:

    $ sudo mariadb
    
  2. Create the databases for the InnoDB and ColumnStore tables using the CREATE DATABASE statement:

    CREATE DATABASE columnstore_db;
    
    CREATE DATABASE innodb_db;
    
  3. Create the InnoDB versions of the HTAP tables using the CREATE TABLE statement:

    USE innodb_db;
    
    CREATE TABLE htap_test1 (id INT) ENGINE = InnoDB;
    
    CREATE TABLE htap_test2 (id INT) ENGINE = InnoDB;
    
  4. Confirm that the tables were replicated using the SHOW TABLES statement:

    SHOW TABLES
       FROM columnstore_db;
    
    +--------------------------+
    | Tables_in_columnstore_db |
    +--------------------------+
    | htap_test1               |
    | htap_test2               |
    +--------------------------+
    
  5. The replication initially creates empty InnoDB tables, which need to be transformed into ColumnStore tables and which need to be populated with the initial copy of the data:

    DROP TABLE IF EXISTS columnstore_db.htap_test1;
    
    CREATE TABLE columnstore_db.htap_test1
      ENGINE=COLUMNSTORE
      SELECT * FROM innodb_db.htap_test1;
    
    DROP TABLE IF EXISTS columnstore_db.htap_test2;
    
    CREATE TABLE columnstore_db.htap_test2
      ENGINE=COLUMNSTORE
      SELECT * FROM innodb_db.htap_test2;
    
  6. Insert data into the InnoDB versions of the HTAP tables using the INSERT statement:

    USE innodb_db;
    
    INSERT INTO htap_test1
       VALUES (100);
    
    INSERT INTO htap_test2
       VALUES (200);
    
  7. Confirm that the data was replicated using the SELECT statement:

    SELECT * FROM columnstore_db.htap_test1;
    
    +------+
    | id   |
    +------+
    |  100 |
    +------+
    
    SELECT * FROM columnstore_db.htap_test2;
    
    +------+
    | id   |
    +------+
    |  200 |
    +------+
    
  8. Create an InnoDB table that will not be replicated:

    USE innodb_db;
    CREATE TABLE transactional_test1 (id INT) ENGINE = InnoDB;
    
  9. Confirm that the table was not replicated:

    SHOW TABLES
       FROM columnstore_db
       LIKE 'transactional_%';
    
    Empty set (0.02 sec)
    
  10. Create a ColumnStore table that will not be replicated:

    USE columnstore_db;
    CREATE TABLE analytical_test1 (id INT) ENGINE = ColumnStore;
    
  11. Confirm that the table was not replicated:

    SHOW TABLES
       FROM innodb_db
       LIKE 'analytical_%';
    
    Empty set (0.02 sec)
    

Check Server Status

  1. Connect to the HTAP server using the MariaDB Client using the root@localhost user account:

    $ sudo mariadb
    Welcome to the MariaDB monitor.  Commands end with ; or \g.
    Your MariaDB connection id is 38
    Server version: 10.5.12-8-MariaDB-Enterprise MariaDB Enterprise Server
    
    Copyright (c) 2000, 2018, Oracle, MariaDB Corporation Ab and others.
    
    Type 'help;' or '\h' for help. Type '\c' to clear the current input statement.
    
    MariaDB [(none)]>
    

Check Replication Status

  1. Connect to the HTAP server using the MariaDB Client using the root@localhost user account:

    $ sudo mariadb
    Welcome to the MariaDB monitor.  Commands end with ; or \g.
    Your MariaDB connection id is 38
    Server version: 10.5.12-8-MariaDB-Enterprise MariaDB Enterprise Server
    
    Copyright (c) 2000, 2018, Oracle, MariaDB Corporation Ab and others.
    
    Type 'help;' or '\h' for help. Type '\c' to clear the current input statement.
    
    MariaDB [(none)]>
    
  2. Execute the SHOW REPLICA STATUS statement.

    This statement returns a lot of columns, but the important ones are Slave_IO_Running and Slave_SQL_Running. If both of those say Yes, then replication is running correctly.

    SHOW REPLICA STATUS\G
    
    *************************** 1. row ***************************
                    Slave_IO_State: Waiting for master to send event
                       Master_Host: localhost
                       Master_User: htap_replication
                       Master_Port: 3306
                     Connect_Retry: 60
                   Master_Log_File: mariadb-bin.000002
               Read_Master_Log_Pos: 695
                    Relay_Log_File: mysqld-relay-bin.000002
                     Relay_Log_Pos: 996
             Relay_Master_Log_File: mariadb-bin.000002
                  Slave_IO_Running: Yes
                 Slave_SQL_Running: Yes
                   Replicate_Do_DB:
               Replicate_Ignore_DB:
                Replicate_Do_Table:
            Replicate_Ignore_Table:
           Replicate_Wild_Do_Table: columnstore_db.htap%
       Replicate_Wild_Ignore_Table:
                        Last_Errno: 0
                        Last_Error:
                      Skip_Counter: 0
               Exec_Master_Log_Pos: 695
                   Relay_Log_Space: 1306
                   Until_Condition: None
                    Until_Log_File:
                     Until_Log_Pos: 0
                Master_SSL_Allowed: No
                Master_SSL_CA_File:
                Master_SSL_CA_Path:
                   Master_SSL_Cert:
                 Master_SSL_Cipher:
                    Master_SSL_Key:
             Seconds_Behind_Master: 0
     Master_SSL_Verify_Server_Cert: No
                     Last_IO_Errno: 0
                     Last_IO_Error:
                    Last_SQL_Errno: 0
                    Last_SQL_Error:
       Replicate_Ignore_Server_Ids:
                  Master_Server_Id: 1
                    Master_SSL_Crl:
                Master_SSL_Crlpath:
                        Using_Gtid: Slave_Pos
                       Gtid_IO_Pos: 0-1-7
           Replicate_Do_Domain_Ids:
       Replicate_Ignore_Domain_Ids:
                     Parallel_Mode: optimistic
                         SQL_Delay: 0
               SQL_Remaining_Delay: NULL
           Slave_SQL_Running_State: Slave has read all relay log; waiting for more updates
                  Slave_DDL_Groups: 1
    Slave_Non_Transactional_Groups: 0
        Slave_Transactional_Groups: 1
    

Limitations

Cross-Database Queries

This implementation relies on replicate_rewrite_db, so it does not support cross-database queries with statement-based replication.

For example, if the replicated database is selected by the USE, then the query will replicate properly:

USE innodb_db;

INSERT INTO htap_test1
   VALUES (100);

SELECT * FROM columnstore_db.htap_test1;
+------+
| id   |
+------+
|  100 |
+------+

However, if the replicated database is not selected, and it is instead prefixed the table name in the query, then the query will not replicate properly:

USE columnstore_db;

INSERT INTO innodb_db.htap_test1
   VALUES (200);

SELECT * FROM columnstore_db.htap_test1;
+------+
| id   |
+------+
|  100 |
+------+

Semi-Synchronous Replication

This implementation has not been tested with semi-synchronous replication.

Parallel Replication

This implementation has not been tested with parallel replication.

Row-Based Replication

This implementation requires the binlog_format system variable to be set to STATEMENT. Row-based replication is not currently supported.