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AWS Aurora read_only status is only available via innodb_read_only #1195

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ottenhoff opened this Issue Oct 3, 2017 · 4 comments

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ottenhoff commented Oct 3, 2017

http://docs.aws.amazon.com/AmazonRDS/latest/UserGuide/Aurora.BestPractices.html

The only way to find the read-only status of an AWS Aurora instance is:

SHOW GLOBAL VARIABLES LIKE 'innodb_read_only';

ProxySQL only checks for 'read_only' so an Aurora read_only instance can never be discovered.

@renecannao renecannao self-assigned this Oct 3, 2017

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renecannao commented Oct 3, 2017

Thank you for reporting this.
Brainstorming, a possible solution could be to add another column in mysql_replication_hostgroups to specify what needs to be checked, either read_only or innodb_read_only , or even super_read_only .

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ottenhoff commented Oct 3, 2017

Yes, a new column provides the most flexibility. Or is it fair to assume that if innodb_read_only is true, the whole server should be treated as a read_only server?

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renecannao commented Oct 3, 2017

I would like to avoid the path of making too many assumptions, because it is possible to have servers without InnoDB (so innodb_read_only won't exist), like ProxySQL admin interface itself or servers that only have TokuDB or only MyRocks.
In the past I have been asked to check super_read_only instead of read_only , so I think it is reasonable to make the check configurable by the end user.

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renecannao commented Jun 11, 2018

This is now implemented in 2.0.0.
@Tusamarco wrote a blog post about it

@renecannao renecannao closed this Jun 11, 2018

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