Re: [HACKERS] Re: [HACKERS] Re: [HACKERS] Windows service is not starting so there’s message in log: FATAL: "could not create shared memory segment “Global/PostgreSQL.851401618”: Permission denied”

On Wed, Mar 9, 2016 at 7:16 AM, Haribabu Kommi <kommi(dot)haribabu(at)gmail(dot)com> wrote:
> On Wed, Mar 9, 2016 at 10:06 PM, Amit Kapila <amit(dot)kapila16(at)gmail(dot)com> wrote:
>> On Wed, Mar 9, 2016 at 11:46 AM, Haribabu Kommi <kommi(dot)haribabu(at)gmail(dot)com>
>> wrote:
>>>
>>>
>>> I tried replacing the random() with PostmaterRandom() for a test and it
>>> worked.
>>> This is generating different random values, so the issue is not occurring.
>>>
>>> "Global/PostgreSQL.2115609797"
>>>
>>> I feel, we should add the the data directory path + the random number to
>>> generate the name for dynamic shared memory, this can fix problem.
>>>
>>
>> As mentioned above, I think if we can investigate why this error is
>> generated, that will be helpful. Currently the code ensures that if the
>> segment already exists, it should retry to create a segment with other name
>> (refer dsm_impl_windows()), so the point of investigation is, why it is not
>> going via that path? I am guessing due to some reason CreateFileMapping()
>> is returning NULL in this case whereas ideally it should return the existing
>> handle with an error ERROR_ALREADY_EXISTS.
>
> DEBUG: mapped win32 error code 5 to 13
>
> Yes, the CreateFileMapping() is returning NULL with an error of
> ERROR_ACCESS_DENIED.
> I am not able to find the reason for this error. This error is occurring only
> when the PostgreSQL is started as a service only.

Another question is: why are both postmasters returning the same
random number? That's not very, uh, random.

--
Robert Haas
EnterpriseDB: http://www.enterprisedb.com
The Enterprise PostgreSQL Company