On Tue, Apr 24, 2018 at 11:18 AM, Stephen Frost <sfr...@snowman.net> wrote: > Greetings, > > * Tom Lane (t...@sss.pgh.pa.us) wrote: >> So far, dory has failed three times with essentially identical symptoms: >> >> 2018-04-23 19:57:10.624 GMT [2240] FATAL: could not reattach to shared >> memory (key=0000000000000190, addr=00000000018E0000): error code 487 >> 2018-04-23 15:57:10.657 EDT [8836] ERROR: lost connection to parallel worker >> 2018-04-23 15:57:10.657 EDT [8836] STATEMENT: select count(*) from tenk1 >> group by twenty; >> 2018-04-23 15:57:10.660 EDT [3820] LOG: background worker "parallel worker" >> (PID 2240) exited with exit code 1 >> >> Now how can this be? We've successfully reserved and released the address >> range we want to use, so it *should* be free at the instant we try to map. > > Yeah, that's definitely interesting.
I wondered if another thread with the right timing could map something between the VirtualFree() and MapViewOfFileEx() calls, but we don't create the Windows signal handling thread until a bit later. Could there be any any other threads active in the process? Maybe try asking what's mapped there with VirtualQueryEx() on failure? -- Thomas Munro http://www.enterprisedb.com
