Re: Let's make PostgreSQL multi-threaded - Mailing list pgsql-hackers

From Heikki Linnakangas
Subject Re: Let's make PostgreSQL multi-threaded
Date
Msg-id 14ee96fe-817a-ff77-95c1-6b5bc0efa616@iki.fi
Whole thread Raw
In response to Re: Let's make PostgreSQL multi-threaded  (Bruce Momjian <bruce@momjian.us>)
Responses Re: Let's make PostgreSQL multi-threaded
List pgsql-hackers
On 05/06/2023 13:10, Bruce Momjian wrote:
> nOn Mon, Jun  5, 2023 at 05:51:57PM +0300, Heikki Linnakangas wrote:
>> # Restart on crash
>>
>> If a backend process crashes, postmaster terminates all other backends and
>> restarts the system. That's hard (impossible?) to do safely if everything
>> runs in one process. We can continue have a separate postmaster process that
>> just monitors the main process and restarts it on crash.
> 
> It would be good to know what new class of errors would cause server
> restarts, e.g., memory allocation failures?

You mean "out of memory"? No, that would be horrible.

I don't think there would be any new class of errors that would cause 
server restarts. In theory, having a separate address space for each 
backend gives you some protection. In practice, there are a lot of 
shared memory structures anyway that you can stomp over, and a segfault 
or unexpected exit of any backend process causes postmaster to restart 
the whole system anyway.

-- 
Heikki Linnakangas
Neon (https://neon.tech)




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