Обсуждение: max_connections documentation
I'm surprised to see that the docs make no mention of how max_connections, max_worker_processes and autovacuum_max_workers(don't) relate. I couldn't remember and had to actually look at the code. I'd like to clarify thisin the max_connecitons section of the documents by doing s/connections/user connections/ and including the formula forMaxBackends (MaxBackends = MaxConnections + autovacuum_max_workers + 1 + max_worker_processes). I'll also mention thatany postgres_fdw connections are considered user connections. Objections? Comments? Also, my understanding is that the parallel stuff will continue to fall under max_worker_processes? -- Jim Nasby, Data Architect, Blue Treble Consulting Data in Trouble? Get it in Treble! http://BlueTreble.com
On Sat, Jan 10, 2015 at 6:20 AM, Jim Nasby <Jim.Nasby@bluetreble.com> wrote:
>
> I'm surprised to see that the docs make no mention of how max_connections, max_worker_processes and autovacuum_max_workers (don't) relate. I couldn't remember and had to actually look at the code. I'd like to clarify this in the max_connecitons section of the documents by doing s/connections/user connections/ and including the formula for MaxBackends (MaxBackends = MaxConnections + autovacuum_max_workers + 1 + max_worker_processes). I'll also mention that any postgres_fdw connections are considered user connections.
>
>
> Also, my understanding is that the parallel stuff will continue to fall under max_worker_processes?
>
> I'm surprised to see that the docs make no mention of how max_connections, max_worker_processes and autovacuum_max_workers (don't) relate. I couldn't remember and had to actually look at the code. I'd like to clarify this in the max_connecitons section of the documents by doing s/connections/user connections/ and including the formula for MaxBackends (MaxBackends = MaxConnections + autovacuum_max_workers + 1 + max_worker_processes). I'll also mention that any postgres_fdw connections are considered user connections.
>
I think it makes sense to add such a clarification in docs, however
not sure if specifying along with max_connections parameter is
good idea as the formula is somewhat internal and is not directly
related to max_connections. How about specifying in below page:
>
> Also, my understanding is that the parallel stuff will continue to fall under max_worker_processes?
Yes.
On 1/10/15 12:06 AM, Amit Kapila wrote: > On Sat, Jan 10, 2015 at 6:20 AM, Jim Nasby <Jim.Nasby@bluetreble.com <mailto:Jim.Nasby@bluetreble.com>> wrote: > > > > I'm surprised to see that the docs make no mention of how max_connections, max_worker_processes and autovacuum_max_workers(don't) relate. I couldn't remember and had to actually look at the code. I'd like to clarify thisin the max_connecitons section of the documents by doing s/connections/user connections/ and including the formula forMaxBackends (MaxBackends = MaxConnections + autovacuum_max_workers + 1 + max_worker_processes). I'll also mention thatany postgres_fdw connections are considered user connections. > > > > I think it makes sense to add such a clarification in docs, however > not sure if specifying along with max_connections parameter is > good idea as the formula is somewhat internal and is not directly > related to max_connections. It's not all that internal; it directly controls how many entries you could end up with in pg_stat_activity. Certainly monitoringsoftware needs to be aware of how this stuff works, and I think many DBAs would want to know as well. Maybe wedon't need the formula itself, but we need to explain what backends do not count towards max_connections (and ideally howto identify them). Maybe the best thing would be to add an "internal" field to pg_stat_activity to indicate what backends were internal andnot user-related... > How about specifying in below page: > > http://www.postgresql.org/docs/devel/static/connect-estab.html I think someone that's concerned about connection limits is much more likely to look at the config section of the docs thanthat section, so we'd need to cross-reference them. Which would probably be good to do anyway... -- Jim Nasby, Data Architect, Blue Treble Consulting Data in Trouble? Get it in Treble! http://BlueTreble.com