leafo/pgmoon

how to set properties of connection pool?

Closed this issue · 9 comments

gzliudan commented

such as pool's size, min and max value, keepalive time, etc.

leafo commented

You can pass the same parameters you pass to the ngx keepalive method to the pg object's keepalive method

https://github.com/leafo/pgmoon#success-err--postgreskeepalive

gzliudan commented

But I didn't find parameters in the source code of pgmoon/init.moon and pgmoon/socket.lua.
By the way, would you please upload pgmoon to http://opm.openresty.org/ ? So I can use opm command to update pgmoon.

leafo commented

@gzliudan the ... is used to pas parameters through to openresty, so their names aren't explicitly listed in this project's source code

I updated the package on opm

gzliudan commented

thanks a lot. I updated pgmoon through opm command.

Can you give an example how to set parameters of connection pool?

leafo commented 
-- when you want to return the connection to the pool:
pg:keepalive(timeout, pool_size)

-- if you need to configure the pool name:
pgmoon.new({
  pool = "custom pool name",  
  -- ...
})

Generally you don't need to configure the pool name since it will choose a reasonable default based on connection settings.

gzliudan commented

Thank you very much.
Does the unit of timeout is second? What happenes if pool_size is different value when call pg:keepalive with last time.

gzliudan commented

Thank you again. Maybe it's better update ReadMe.

devvit commented

52 closed, continue here.

There are similar issues: 47, 64

How to limit connections in openresty? The answer is here

Basically, we cannot strictly limit connections, in practice, lua_socket_pool_size or #tcpsocksetkeepalive is both overflow-able, that's why cosocket has huge concurrency.

openresty group has more details, for example this