Details
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Bug
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Status: In Review (View Workflow)
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Critical
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Resolution: Unresolved
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10.3(EOL), 10.5
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None
Description
Hi, I'm new here so I'm not really sure what are the minimal requirements for a bug report so I'll just work from my own experience for now:
We had an incident this morning whereby an ALTER TABLE statement was executed on a server in a cluster of 3 servers. This became an outage for us because the statement resulted in a COPY algorithm being used on a large table (in member 2 and 3 of the cluster) which (at least in my opinion) should have been prevented by the statements that were done on member 1 of the cluster:
SET SESSION alter_algorithm="INSTANT";
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alter table some_large_table_containing_blobs
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modify type enum ('existing_option1','existing_option3','existing_option2') null;
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Note that the enum order changed by accident which caused the COPY algorithm to be needed which made it fail on member 1 which in turn didn't stop it from propagating the query to the other cluster members somehow (this seems like unwanted behavior to me). I've checked this by using SHOW PROCESSLIST; on all machines and found that it was only running on both members 2 and 3 while it clearly showed me the following error on member 1 to which I was connected while running the queries: ALGORITHM=INSTANT is not supported. Reason: Cannot change column type. Try ALGORITHM=COPY
Some version information:
[root@db1 ~]# yum list installed | grep galera
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galera.x86_64 25.3.37-1.el7.centos @mariadb-main
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[root@db1 ~]# yum list installed | grep MariaDB
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MariaDB-backup.x86_64 10.3.36-1.el7.centos @mariadb-main
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MariaDB-client.x86_64 10.3.36-1.el7.centos @mariadb-main
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MariaDB-common.x86_64 10.3.36-1.el7.centos @mariadb-main
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MariaDB-compat.x86_64 10.3.36-1.el7.centos @mariadb-main
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MariaDB-server.x86_64 10.3.36-1.el7.centos @mariadb-main
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I was wondering if this might be a known issue somehow? Or if this is really a bug? And if so is it a bug in Galera or in MariaDB?
Attachments
Issue Links
- relates to
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MDEV-30714 SET SESSION ALGORITHM causes operational issues with replication
- Closed
- links to