On Tue, Jun 6, 2017 at 10:14 PM, Tom Lane <t...@sss.pgh.pa.us> wrote: > Robert Haas <robertmh...@gmail.com> writes: >> I think the idea of retrying process creation (and I definitely agree >> with Tom and Magnus that we have to retry process creation, not just >> individual mappings) is a good place to start. Now if we find that we >> are having to retry frequently, then I think we might need to try >> something along the lines of what Andres proposed and what nginx >> apparently did. However, any fixed address will be prone to >> occasional failures (or maybe, on some systems, regular failures) if >> that particular address happens to get claimed by something. I don't >> think we can say that there is any address where that definitely won't >> happen. So I would say let's do this retry thing first, and then if >> that proves inadequate, we can also try moving the mappings to a range >> where conflicts are less likely. > > By definition, the address range we're trying to reuse worked successfully > in the postmaster process. I don't see how forcing a specific address > could do anything but create an additional risk of postmaster startup > failure. >
I think it won't create an additional risk, because the idea is that if we fail to map the shm segment at a predefined address, then we will allow the system to choose the initial address as we are doing now. So, it can reduce chances of doing retries. -- With Regards, Amit Kapila. EnterpriseDB: http://www.enterprisedb.com -- Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers