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

Dear Fujii-san,

Thank you for your interest! I'll post new version within several days.

> > Yeah, remote-checking timeout will be enable even ifa local transaction is
> opened.
> > In my understanding, postgres cannot distinguish whether opening transactions
> > are using only local object or not.
> > My first idea was that turning on the timeout when GetFdwRoutineXXX
> functions
> > were called,
> 
> What about starting the timeout in GetConnection(), instead?

Did you said about a function in postgres_fdw/connection.c?
In my understanding that means that the timeout should be enabled or disabled
by each FDW extensions.
I did not find bad cases for that, so I'll change like that and make new APIs.

> v05_0004_add_tests.patch failed to be applied to the master. Could you rebase it?

It's caused because a testcase was added in postgres_fdw. Will rebase.

> The above change is included in both
> v5-0003-Use-WL_SOCKET_CLOSED-for-client_connection_check_.patch and
> v05_0002_add_doc.patch. If it should be in the former patch, it should be removed
> from your patch v05_0002_add_doc.patch.

I confused about doc-patch. Sorry for inconvenience.

> There seems no user of UnregisterCheckingRemoteServersCallback(). So how
> about removing it?

Previously I kept the API for any other extensions, but I cannot find use cases.
Will remove.

Best Regards,
Hayato Kuroda
FUJITSU LIMITED