[Pgpool-general] Raw mode instead of connection caching/pooling

[Tatsuo Ishii]

> Greetings,
> 
> I'd like to try out raw mode (ie, NO connection pooling/caching), but the
> documentation doesn't explicitly state how to configure it.
> 
> I tried commenting out max_pool, but the default for that option is 4
> (correct?).
> max_pool = 0 crashes pgpool with "could not create shared memory segment:
> Invalid argument".

You do not need to touch max_pool if you do not want to use connection
pooling/caching.

> I'm now trying this:
> 
> master_slave_mode = true
> load_balance_mode = true
> connection_cache  = false
> #max_pool        = 0
> backend_hostname0 = 'master'
> backend_port0     = 5432
> backend_weight0   = 0
> backend_hostname1 = 'slave0'
> backend_port1     = 5431
> backend_weight1   = 1
> 
> 
> Selects *do* seem to be going to the local slave, while updates are going
> to the master.  Is this configuration correct to achieve NO
> pooling/caching of connections - ie, always send connections directly to
> backends?

Yes.

connection_cache  = false

is what all you need.

> Connection caching/pooling is crashing under high volume (even if we set
> child_max_connections/connection_life_time/child_life_time), so raw mode
> seems like the last resort before we abandon pgpool in favour of an
> application rewrite.  We're only really interested in redirecting
> UPDATE/INSERT/DELETE anyway, so using raw mode doesn't hurt in our case.

Can you tell more about your experience with connection
caching/pooling problem?
--
Tatsuo Ishii
SRA OSS, Inc. Japan