[pgpool-general: 6426] Re: Request for support regarding pg pool hardware sizing
ishii at sraoss.co.jp
Wed Feb 20 21:25:15 JST 2019
> I need to know if there are specific guidelines for hardware sizing for pg
> pool server since I can't find enough information online.
> Can anyone guide me on this? or tell me what numbers are needed from my
> side to be able to estimate the hardware sizing needed?
> I'm interested more in terms of CPU and RAM in the current status.
Here are very rough guide lines.
- Basic RAM requirement: 5MB * num_init_children. For example if you
have num_init_children = 32 (the default), you need 160MB.
- Shared memory: num_init_children * max_pool * 17408. For example if
you have num_init_children = 32 (the default) and max_pool = 4 (the
default), you need 32 * 4 * 17408 = 2228224 bytes = 2.1 MB.
- If you plan to use in memory query cache with shared memory, you
need more RAM for it. See memqcache_max_num_cache section in the
Pgpool-II doc for required RAM size.
- If you plan to use extended query protocol (i.e. prepared queries in
Java and other languages), existing releases may consume much more
RAM. It will be fixed in the next minor releases, planed to be
released on February 21th.
- If you plan to assign large number to num_init_children, you need
more CPU. It's hard to tell exactly how many cores you need, because
that's depending on what type of SQL queries you are going to use.
If a query does not take long time in PostgreSQL, it is likely that
more CPU is consumed by Pgpool-II. On the other hand, if a query
takes long time, Pgpool-II needs less CPU.
SRA OSS, Inc. Japan
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