Re: Access a Postgres storage with two independent instances - Mailing list pgsql-novice

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Subject Re: Access a Postgres storage with two independent instances
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In response to Re: Access a Postgres storage with two independent instances  (Alan Hodgson <ahodgson@lists.simkin.ca>)
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Re: Access a Postgres storage with two independent instances
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Actually what I want is multiple Postgres instances to have read and write access to the same data storage directory. Anyway, that can not be possible as what you say. But, when I deploy MySQL/MongoDB deployment with multiple replicas to access the same storage, the all pods except one become CrashLoopBackOff state. This is happening for MySQL/Mongo. When it comes to Postgres, I deployed it with multiple pods, all the pods became healthy and there is no such CrashLoopBackOff state occurred. But those pods access different storages for every pod. Why this totally different from MySQL and Mongo?

On Tue, May 7, 2024 at 2:34 AM Alan Hodgson <ahodgson@lists.simkin.ca> wrote:
On Tue, 2024-05-07 at 00:47 +0530, first last wrote:
tried to deploy Postgres deployment with Kubernetes, having three replicas that are accessing the same storage(PVC). Here is the configuration

Finally, my question is, why the scenario is different for MySQL and Postgres?  Could you please help me to figure out the issue? This is for my Final year project testing Kubernetes using fuzzing.


Not sure what you're trying to accomplish, but PostgreSQL can definitely not share storage between active postmasters. Nor can MySQL, afaik.

On Tue, May 7, 2024 at 2:34 AM Alan Hodgson <ahodgson@lists.simkin.ca> wrote:
On Tue, 2024-05-07 at 00:47 +0530, first last wrote:
tried to deploy Postgres deployment with Kubernetes, having three replicas that are accessing the same storage(PVC). Here is the configuration

Finally, my question is, why the scenario is different for MySQL and Postgres?  Could you please help me to figure out the issue? This is for my Final year project testing Kubernetes using fuzzing.


Not sure what you're trying to accomplish, but PostgreSQL can definitely not share storage between active postmasters. Nor can MySQL, afaik.

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