MariaDB/Galera Cluster with 3 nodes - Change ENGINE from MyISAM to InnoDB without crash
https://dba.stackexchange.com/questions/128715
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30-09-2020 - |
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We have tables with MyISAM. The are out of sync, the number of records is different on each cluster node
> select table_schema, table_name from tables where ENGINE = 'MyISAM' and table_schema != 'mysql';
+--------------+------------+
| table_schema | table_name |
+--------------+------------+
| nrmtz | tablename1 |
| nrmwetr | tablename1 |
| nrmrzhredr | tablename1 |
| nrmesfw | tablename1 |
| sdtz | tablename1 |
| sdwetr | tablename1 |
| sdrzhredr | tablename1 |
| sdesfw | tablename1 |
| smtz | tablename1 |
| smwetr | tablename1 |
| smrzhredr | tablename1 |
| smesfw | tablename1 |
+--------------+------------+
12 rows in set (0.02 sec)
> desc tablename1;
+--------------+------------+------+-----+---------+----------------+
| Field | Type | Null | Key | Default | Extra |
+--------------+------------+------+-----+---------+----------------+
| id | int(11) | NO | PRI | NULL | auto_increment |
| migration_id | bigint(20) | NO | UNI | NULL | |
+--------------+------------+------+-----+---------+----------------+
2 rows in set (0.00 sec)
-> ;
+-----------+------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+
| Table | Create Table |
+-----------+------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+
| gomigrate | CREATE TABLE `tablename1` (
`id` int(11) NOT NULL AUTO_INCREMENT,
`migration_id` bigint(20) NOT NULL,
PRIMARY KEY (`id`),
UNIQUE KEY `migration_id` (`migration_id`)
) ENGINE=MyISAM AUTO_INCREMENT=23 DEFAULT CHARSET=utf8 |
+-----------+------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+
1 row in set (0.00 sec)
Our version (we can't upgrade easy) and cluster status
> select VERSION();
+----------------------+
| VERSION() |
+----------------------+
| 5.5.41-MariaDB-wsrep |
+----------------------+
1 row in set (0.00 sec)
> show status like '%wsrep%';
+------------------------------+-------------------------------------------------+
| Variable_name | Value |
+------------------------------+-------------------------------------------------+
| wsrep_local_state_uuid | 927d368c-b92d-11e5-bb07-2647ef235310 |
| wsrep_protocol_version | 5 |
| wsrep_last_committed | 5592805 |
| wsrep_replicated | 4287245 |
| wsrep_replicated_bytes | 2067046243 |
| wsrep_repl_keys | 12903900 |
| wsrep_repl_keys_bytes | 201838365 |
| wsrep_repl_data_bytes | 1590824198 |
| wsrep_repl_other_bytes | 0 |
| wsrep_received | 1350734 |
| wsrep_received_bytes | 676386342 |
| wsrep_local_commits | 4285656 |
| wsrep_local_cert_failures | 1 |
| wsrep_local_replays | 0 |
| wsrep_local_send_queue | 0 |
| wsrep_local_send_queue_avg | 0.000431 |
| wsrep_local_recv_queue | 0 |
| wsrep_local_recv_queue_avg | 0.013302 |
| wsrep_local_cached_downto | 5353930 |
| wsrep_flow_control_paused_ns | 0 |
| wsrep_flow_control_paused | 0.000000 |
| wsrep_flow_control_sent | 0 |
| wsrep_flow_control_recv | 0 |
| wsrep_cert_deps_distance | 12.204780 |
| wsrep_apply_oooe | 0.034583 |
| wsrep_apply_oool | 0.000000 |
| wsrep_apply_window | 1.036009 |
| wsrep_commit_oooe | 0.000000 |
| wsrep_commit_oool | 0.000000 |
| wsrep_commit_window | 1.001590 |
| wsrep_local_state | 4 |
| wsrep_local_state_comment | Synced |
| wsrep_cert_index_size | 23 |
| wsrep_causal_reads | 0 |
| wsrep_cert_interval | 0.072367 |
| wsrep_incoming_addresses | 192.168.5.32:3306,192.168.5.31:3306,192.168.5.33:3306 |
| wsrep_cluster_conf_id | 7 |
| wsrep_cluster_size | 3 |
| wsrep_cluster_state_uuid | 927d368c-b92d-11e5-bb07-2647ef235310 |
| wsrep_cluster_status | Primary |
| wsrep_connected | ON |
| wsrep_local_bf_aborts | 0 |
| wsrep_local_index | 1 |
| wsrep_provider_name | Galera |
| wsrep_provider_vendor | Codership Oy <info@codership.com> |
| wsrep_provider_version | 3.5(rXXXX) |
| wsrep_ready | ON |
| wsrep_thread_count | 2 |
+------------------------------+-------------------------------------------------+
48 rows in set (0.00 sec)
I need the tables to be InnoDB and in sync. Those two statements crashing.
CREATE TABLE test ENGINE=InnoDB SELECT * FROM nrmtz.tablename1;
ALTER TABLE tablename1 ENGINE=InnoDB;
Are there other ways doing it without crash?
Lösung
I need the tables to be InnoDB and in sync. Those two statements crashing.
Does it crash with a stack trace in the server logs? Could you share it here? I tried the above two commands on a 2-node MariaDB-5.5.47 cluster and it worked as expected.
As @jkavalik suggested, you could do something like the following :
- Create a new INNODB table with the same definition. This table gets replicated to other nodes.
- Dump data from the old table into a file
SELECT ... INTO OUTFILE ... - Reload data from the file into the new table
LOAD DATA INFILE ... [REPLACE|IGNORE] .... The inserted records also get replicated to other nodes. - Repeat 2-3 on other nodes.
- Rename table created in step 1.
Andere Tipps
MyISAM support in galera is cough beta at best.
The best thing to do is: mysqldump ... -T db table_name > dump.sql (this will make a .sql and .txt file) drop the myisam table edit the .sql file and change ENGINE=MYISAM to ENGINE=INNODB LOAD DATA INFILE 'table.txt' INTO TABLE table_name;
Do this on whatever node that you want to treat as the "source of truth".
If you want a consistent table with records from all nodes, then do the above, then use sort to sort the tables (using the PK, ideally an auto-increment) removing the duplicates, then import the .txt with records from all tables.
