Thread: [DOCS] remove shmmax example in Linux section
The following documentation comment has been logged on the website: Page: https://www.postgresql.org/docs/9.5/static/kernel-resources.html Description: Hi, I'm refer to this document: https://www.postgresql.org/docs/9.5/static/kernel-resources.html In "Linux" section, show an example of setting shmmax to 16GB, when this change is not needed from pg 9.3. Maybe just remove to avoid confusion? Maybe also shmall also not needed ? Regards, Gorka
On 7/21/17 06:18, gorka.gil@openbravo.com wrote: > The following documentation comment has been logged on the website: > > Page: https://www.postgresql.org/docs/9.5/static/kernel-resources.html > Description: > > Hi, > > I'm refer to this document: > https://www.postgresql.org/docs/9.5/static/kernel-resources.html > > In "Linux" section, show an example of setting shmmax to 16GB, when this > change is not needed from pg 9.3. > > Maybe just remove to avoid confusion? > Maybe also shmall also not needed ? It's still needed in some cases, so I don't see why we can't have an example. -- Peter Eisentraut http://www.2ndQuadrant.com/ PostgreSQL Development, 24x7 Support, Remote DBA, Training & Services
Peter Eisentraut <peter.eisentraut@2ndquadrant.com> writes: > On 7/21/17 06:18, gorka.gil@openbravo.com wrote: >> In "Linux" section, show an example of setting shmmax to 16GB, when this >> change is not needed from pg 9.3. >> >> Maybe just remove to avoid confusion? >> Maybe also shmall also not needed ? > It's still needed in some cases, so I don't see why we can't have an > example. I wonder whether it'd make sense to recast those examples as increasing semaphore-related settings, as that's much more likely to be needed these days. I had to boost the SEMMNI setting on my workstation just last week. (Admittedly, I had something like a dozen postmasters going, but still, that was an actual change I had to make.) It'd be particularly valuable to document this for Linux, with its opaque "kernel.sem" API for the semaphore limits. regards, tom lane
On Mon, Jul 31, 2017 at 11:48 AM, Tom Lane <tgl@sss.pgh.pa.us> wrote: > Peter Eisentraut <peter.eisentraut@2ndquadrant.com> writes: >> On 7/21/17 06:18, gorka.gil@openbravo.com wrote: >>> In "Linux" section, show an example of setting shmmax to 16GB, when this >>> change is not needed from pg 9.3. >>> >>> Maybe just remove to avoid confusion? >>> Maybe also shmall also not needed ? > >> It's still needed in some cases, so I don't see why we can't have an >> example. > > I wonder whether it'd make sense to recast those examples as increasing > semaphore-related settings, as that's much more likely to be needed these > days. I had to boost the SEMMNI setting on my workstation just last week. > (Admittedly, I had something like a dozen postmasters going, but still, > that was an actual change I had to make.) It'd be particularly valuable > to document this for Linux, with its opaque "kernel.sem" API for the > semaphore limits. Agreed. I ran into this many years ago with multiple clusters on a box and it is definitely non-obvious.