MySQL Group Replication plugin not found in version 5.7.19, 5.7.21

Question

I am attempting to enable the MySQL group replication plugin on MySQL 5.7.21, which should be available in 5.7 as per the documentation (https://dev.mysql.com/doc/refman/5.7/en/group-replication.html)

$ mysql --version
mysql  Ver 14.14 Distrib 5.7.21, for Linux (x86_64) using  EditLine wrapper

When I attempt to enable the plugin through MySQL:

$ mysql> INSTALL PLUGIN group_replication SONAME 'group_replication.so';
ERROR 1126 (HY000): Can't open shared library '/usr/lib/mysql/plugin/group_replication.so' (errno: 2 /usr/lib/mysql/plugin/group_replication.so: cannot open shared object file: No such file or directory)

The output of my plugins in MySQL:

$ mysql> SHOW PLUGINS;
+----------------------------+----------+--------------------+---------+---------+
| Name                       | Status   | Type               | Library | License |
+----------------------------+----------+--------------------+---------+---------+
| binlog                     | ACTIVE   | STORAGE ENGINE     | NULL    | GPL     |
| mysql_native_password      | ACTIVE   | AUTHENTICATION     | NULL    | GPL     |
| sha256_password            | ACTIVE   | AUTHENTICATION     | NULL    | GPL     |
| CSV                        | ACTIVE   | STORAGE ENGINE     | NULL    | GPL     |
| MEMORY                     | ACTIVE   | STORAGE ENGINE     | NULL    | GPL     |
| InnoDB                     | ACTIVE   | STORAGE ENGINE     | NULL    | GPL     |
| INNODB_TRX                 | ACTIVE   | INFORMATION SCHEMA | NULL    | GPL     |
| INNODB_LOCKS               | ACTIVE   | INFORMATION SCHEMA | NULL    | GPL     |
| INNODB_LOCK_WAITS          | ACTIVE   | INFORMATION SCHEMA | NULL    | GPL     |
| INNODB_CMP                 | ACTIVE   | INFORMATION SCHEMA | NULL    | GPL     |
| INNODB_CMP_RESET           | ACTIVE   | INFORMATION SCHEMA | NULL    | GPL     |
| INNODB_CMPMEM              | ACTIVE   | INFORMATION SCHEMA | NULL    | GPL     |
| INNODB_CMPMEM_RESET        | ACTIVE   | INFORMATION SCHEMA | NULL    | GPL     |
| INNODB_CMP_PER_INDEX       | ACTIVE   | INFORMATION SCHEMA | NULL    | GPL     |
| INNODB_CMP_PER_INDEX_RESET | ACTIVE   | INFORMATION SCHEMA | NULL    | GPL     |
| INNODB_BUFFER_PAGE         | ACTIVE   | INFORMATION SCHEMA | NULL    | GPL     |
| INNODB_BUFFER_PAGE_LRU     | ACTIVE   | INFORMATION SCHEMA | NULL    | GPL     |
| INNODB_BUFFER_POOL_STATS   | ACTIVE   | INFORMATION SCHEMA | NULL    | GPL     |
| INNODB_TEMP_TABLE_INFO     | ACTIVE   | INFORMATION SCHEMA | NULL    | GPL     |
| INNODB_METRICS             | ACTIVE   | INFORMATION SCHEMA | NULL    | GPL     |
| INNODB_FT_DEFAULT_STOPWORD | ACTIVE   | INFORMATION SCHEMA | NULL    | GPL     |
| INNODB_FT_DELETED          | ACTIVE   | INFORMATION SCHEMA | NULL    | GPL     |
| INNODB_FT_BEING_DELETED    | ACTIVE   | INFORMATION SCHEMA | NULL    | GPL     |
| INNODB_FT_CONFIG           | ACTIVE   | INFORMATION SCHEMA | NULL    | GPL     |
| INNODB_FT_INDEX_CACHE      | ACTIVE   | INFORMATION SCHEMA | NULL    | GPL     |
| INNODB_FT_INDEX_TABLE      | ACTIVE   | INFORMATION SCHEMA | NULL    | GPL     |
| INNODB_SYS_TABLES          | ACTIVE   | INFORMATION SCHEMA | NULL    | GPL     |
| INNODB_SYS_TABLESTATS      | ACTIVE   | INFORMATION SCHEMA | NULL    | GPL     |
| INNODB_SYS_INDEXES         | ACTIVE   | INFORMATION SCHEMA | NULL    | GPL     |
| INNODB_SYS_COLUMNS         | ACTIVE   | INFORMATION SCHEMA | NULL    | GPL     |
| INNODB_SYS_FIELDS          | ACTIVE   | INFORMATION SCHEMA | NULL    | GPL     |
| INNODB_SYS_FOREIGN         | ACTIVE   | INFORMATION SCHEMA | NULL    | GPL     |
| INNODB_SYS_FOREIGN_COLS    | ACTIVE   | INFORMATION SCHEMA | NULL    | GPL     |
| INNODB_SYS_TABLESPACES     | ACTIVE   | INFORMATION SCHEMA | NULL    | GPL     |
| INNODB_SYS_DATAFILES       | ACTIVE   | INFORMATION SCHEMA | NULL    | GPL     |
| INNODB_SYS_VIRTUAL         | ACTIVE   | INFORMATION SCHEMA | NULL    | GPL     |
| MyISAM                     | ACTIVE   | STORAGE ENGINE     | NULL    | GPL     |
| MRG_MYISAM                 | ACTIVE   | STORAGE ENGINE     | NULL    | GPL     |
| PERFORMANCE_SCHEMA         | ACTIVE   | STORAGE ENGINE     | NULL    | GPL     |
| ARCHIVE                    | ACTIVE   | STORAGE ENGINE     | NULL    | GPL     |
| BLACKHOLE                  | ACTIVE   | STORAGE ENGINE     | NULL    | GPL     |
| FEDERATED                  | DISABLED | STORAGE ENGINE     | NULL    | GPL     |
| partition                  | ACTIVE   | STORAGE ENGINE     | NULL    | GPL     |
| ngram                      | ACTIVE   | FTPARSER           | NULL    | GPL     |
+----------------------------+----------+--------------------+---------+---------+
44 rows in set (0.01 sec)

This is the contents of the plugin directory:

$ ls -lah /usr/lib/mysql/plugin/
total 644K
drwxr-xr-x 2 root root 4.0K Sep 26 23:24 .
drwxr-xr-x 3 root root 4.0K Sep 26 23:24 ..
-rw-r--r-- 1 root root  21K Jul 19 14:10 adt_null.so
-rw-r--r-- 1 root root 6.2K Jul 19 14:10 auth_socket.so
-rw-r--r-- 1 root root  44K Jul 19 14:10 connection_control.so
-rw-r--r-- 1 root root 107K Jul 19 14:10 innodb_engine.so
-rw-r--r-- 1 root root  79K Jul 19 14:10 keyring_file.so
-rw-r--r-- 1 root root 151K Jul 19 14:10 libmemcached.so
-rw-r--r-- 1 root root 9.7K Jul 19 14:10 locking_service.so
-rw-r--r-- 1 root root  11K Jul 19 14:10 mypluglib.so
-rw-r--r-- 1 root root 6.2K Jul 19 14:10 mysql_no_login.so
-rw-r--r-- 1 root root  55K Jul 19 14:10 rewriter.so
-rw-r--r-- 1 root root  56K Jul 19 14:10 semisync_master.so
-rw-r--r-- 1 root root  15K Jul 19 14:10 semisync_slave.so
-rw-r--r-- 1 root root  27K Jul 19 14:10 validate_password.so
-rw-r--r-- 1 root root  31K Jul 19 14:10 version_token.so

These are the contents of my config:

cat /etc/mysql/my.cnf

    [mysqld_safe]
    nice                                    = 0
    socket                                  = /var/run/mysqld/mysqld.sock

    [mysqld]
    basedir                                 = /usr
    bind_address                            = 123.45.67.89
    binlog_checksum                         = NONE
    binlog_format                           = ROW
    datadir                                 = /var/lib/mysql
    enforce_gtid_consistency                = ON
    expire_logs_days                        = 10
    general_log                             = 1
    general_log_file                        = /var/log/mysql/mysql.log
    gtid_mode                               = ON
    key_buffer_size                         = 8388608
    lc_messages_dir                         = /usr/share/mysql
    log_bin                                 = binlog
    log_error                               = /var/log/mysql/mysql_error.log
    log_slave_updates                       = ON
    long_query_time                         = 60
    loose-group_replication_bootstrap_group = OFF
    loose-group_replication_enforce_update_everywhere_checks= ON
    loose-group_replication_group_name      = 34dee7cd-d20d-4f59-9500-f56ada9a1abz
    loose-group_replication_group_seeds     = 123.45.67.88:33061,123.45.67.89:33061
    loose-group_replication_ip_whitelist    = 123.45.67.88,123.45.67.89
    loose-group_replication_local_address   = 123.45.67.89:33061
    loose-group_replication_recovery_use_ssl= 1
    loose-group_replication_single_primary_mode= OFF
    loose-group_replication_ssl_mode        = REQUIRED
    loose-group_replication_start_on_boot   = OFF
    master_info_repository                  = TABLE
    max_allowed_packet                      = 16M
    max_binlog_size                         = 100M
    max_connect_errors                      = 100000000
    pid-file                                = /var/run/mysqld/mysqld.pid
    port                                    = 3306
    query_cache_limit                       = 1M
    query_cache_size                        = 16M
    relay_log                               = my-project-prod-relay-bin
    relay_log_info_repository               = TABLE
    report_host                             = 123.45.67.88
    require_secure_transport                = ON
    server_id                               = 2
    skip_external_locking
    slow_query_log                          = 1
    slow_query_log_file                     = /var/log/mysql/mysql-slow-query.log
    socket                                  = /var/run/mysqld/mysqld.sock
    thread_cache_size                       = 8
    thread_stack                            = 192K
    tmpdir                                  = /tmp
    transaction_write_set_extraction        = XXHASH64
    user                                    = mysql

    [mysqldump]
    max_allowed_packet                      = 16M
    quick
    quote_names

    [mysql]
    no-auto-rehash

    [isamchk]
    key_buffer_size                         = 16M

    [client]
    port                                    = 3306
    socket                                  = /var/run/mysqld/mysqld.sock

    !includedir /etc/mysql/conf.d/

I'm wondering if I'm using the wrong version of MySQL or if there is some other step needed to install the group replication plugin?

Answer 1

FWIW I downloaded 5.7.19 Community Edition https://dev.mysql.com/doc/refman/5.7/en/group-replication.html to run it in a sandbox, and I confirm that the group replication .so file is present.

I got the plugin to load with the INSTALL PLUGIN statement, just like you tried.

First I had to add some config settings, which are documented in https://dev.mysql.com/doc/refman/5.7/en/group-replication-configuring-instances.html

server_id=1 # or any value unique among your replica set
gtid_mode=ON
enforce_gtid_consistency=ON
master_info_repository=TABLE
relay_log_info_repository=TABLE
binlog_checksum=NONE
log_slave_updates=ON
log_bin=binlog
binlog_format=ROW

And of course restart mysqld after editing the config settings.

According to discussion here, it looks like the group replication plugin may have been intentionally left out of the normal MySQL server edition.

To know if you are running the Community Edition, run mysql:

> mysql -u root -p
Welcome to the MySQL monitor.  Commands end with ; or \g.
Your MySQL connection id is 3
Server version: 5.7.20-log MySQL Community Server (GPL)
.....

To manually install the Community Edition 5.7 (or other archived versions here: https://downloads.mysql.com/archives/community/), run the following commands:

sudo apt-get install libaio1
sudo apt-get install libmecab2
curl -OL https://downloads.mysql.com/archives/get/file/mysql-common_5.7.20-1ubuntu16.04_amd64.deb
curl -OL https://downloads.mysql.com/archives/get/file/mysql-community-client_5.7.20-1ubuntu16.04_amd64.deb
curl -OL https://downloads.mysql.com/archives/get/file/mysql-client_5.7.20-1ubuntu16.04_amd64.deb
curl -OL https://downloads.mysql.com/archives/get/file/mysql-community-server_5.7.20-1ubuntu16.04_amd64.deb
sudo dpkg -i mysql-common_5.7.20-1ubuntu16.04_amd64.deb
sudo dpkg -i mysql-community-client_5.7.20-1ubuntu16.04_amd64.deb
sudo dpkg -i mysql-client_5.7.20-1ubuntu16.04_amd64.deb
sudo dpkg -i mysql-community-server_5.7.20-1ubuntu16.04_amd64.deb   

Answer 2

Bumped into the same issue. Bill's answer and the link to why it's not included in the standard version pointed me in the right direction, then I found Luis' answer here. The linked guide shows that after installing mysql-apt-config, apt-get install mysql-server fetches the community version by default. This allowed me to proceed with installing the plugin, although I had an extra error:

ERROR 1123 (HY000): Can't initialize function 'group_replication'; Plugin initialization function failed.

When I checked /var/log/mysql/error.log, I saw it fails because:

2018-07-04T14:19:36.039987Z 5 [ERROR] For the creation of replication channels the master info and relay log info repositories must be set to TABLE

Providing the right Group Replication-ready configuration to MySQL solved it. In my case that was simply restarting the MySQL server since I had provisioned it with Ansible but it hadn't taken effect. Hope that helps anyone dealing with Group Replication.

EDIT: While the above works, it created problems when using the Geerlingguy Ansible role, so instead of installing Community Server, I ended up provisioning the plugin directly with the following Ansible code:

    - name: Provision the MySQL group_replication plugin
  copy:
    src: group_replication.so
    dest: /usr/lib/mysql/plugin/group_replication.so
    mode: 0644

I got the plugin from the community version of MySQL though, but I can say it's another valid approach that's better suited to some situations.