How do I make a PSGI program do costly initialisation only once per process, not per thread?
For whatever reason, the program thrall hard-coded a "loader" parameter in its configuration section:
my $runner = Plack::Runner->new( server => 'Thrall', env => 'deployment', loader => 'Delayed', version_cb => \&version,);$runner->parse_options(@ARGV);That string "Delayed" refers to the module Plack::Loader::Delayed, which delays the loading of .psgi files until first request comes. That would match your benchmarking result. (If you re-run the benchmark again without killing thrall, you'll see identical output).
You may try running thrall -L +Plack::Loader app.psgi, which reverts the "loader" parameter to the default value hard-coded in Plack::Runner.