Added reloading storage configuration from configuration file

[excitoon]

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• New Feature

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Added reloading storage configuration from configuration file.

[nvartolomei]

This is exciting. Can you share more about the intention here and what use cases you want to support? Ie. will it be possible to just remove a disk and ClickHouse will run part checks/repair for replicated tables and missing parts?

[alexey-milovidov]

@excitoon Any updates?

@nvartolomei

Ie. will it be possible to just remove a disk and ClickHouse will run part checks/repair for replicated tables and missing parts?

If parts are not available or not readable, ClickHouse will download them from replicas. Removing a disk and removing it from the configuration will work.

[alexey-milovidov]

boost::shared_ptr - looks strange.
Is the assignment operator atomic by default (it's unlikely)?
Why don't use MultiVersion as discussed?

[alexey-milovidov]

(rebased but boost::shared_ptr remains)

[excitoon]

@alexey-milovidov I did not use MultiVersion because shared_ptr looks simpler thing to me.

[BayoNet]

@excitoon
Hello.
Could you explain how to use it?
Update storage config first and call SYSTEM UPDATE CONFIG then?
Are there some tricky things?

[alexey-milovidov]

@BayoNet The configuration will be updated automatically when user has changed the config file.