Re: [Proposal] Add foreign-server health checks infrastructure

On 2022/02/17 19:35, kuroda.hayato@fujitsu.com wrote:
> Dear Horiguchi-san,
> 
>> I think we just don't need to add the special timeout kind to the
>> core.  postgres_fdw can use USER_TIMEOUT and it would be suffiction to
>> keep running health checking regardless of transaction state then fire
>> query cancel if disconnection happens. As I said in the previous main,
>> possible extra query cancel woud be safe.

Sounds reasonable to me.


> I finally figured out that you mentioned about user-defined timeout system.
> Firstly - before posting to hackers - I designed like that,
> but I was afraid of an overhead that many FDW registers timeout
> and call setitimer() many times. Is it too overcautious?

Isn't it a very special case where many FDWs use their own user timeouts? Could you tell me the assumption that you're
thinking,especially how many FDWs are working?
 

Regards,

-- 
Fujii Masao
Advanced Computing Technology Center
Research and Development Headquarters
NTT DATA CORPORATION