Re: Echo module, possible bug

agentzh · 2013-02-12T03:35:15+00:00

Hello! On Wed, Jan 30, 2013 at 5:47 AM, Onur Bozkurt wrote: > Is there particular reason that echo directive runs much slower than > content_by_lua &q...

Re: Echo module, possible bug

agentzh

Hello!

On Mon, Feb 11, 2013 at 2:42 AM, Onur Bozkurt wrote:
> I'm also wondering if ngx-lua has a directive to run Lua scripts outside of
> the event loop. init_by_lua directive doesn't seem to have cosockets which
> I'd like to use.

For using sockets in init_by_lua, see the discussion in this GitHub ticket:

    https://github.com/chaoslawful/lua-nginx-module/issues/206

> I got worse performance with re-connecting to Redis for
> each request (even with connection pool).
>

Worse than what?

Are you sure your connection pool is properly enabled? You should
always check the turn values of the set_keepalive() method. People
tend to use this method in the wrong way because the method name could
be a bit misleading.

Also, whenever you see things are slow, you're strongly recommended to
use the FlameGraph tools to analyse your Nginx processes on both the C
and Lua levels.

If you're on Linux, just check out the ngx-sample-bt and
ngx-sample-lua-bt scripts in my Nginx Systemtap Toolkit:

    https://github.com/agentzh/nginx-systemtap-toolkit#ngx-sample-bt
    https://github.com/agentzh/nginx-systemtap-toolkit#ngx-sample-lua-bt

If the cosocket "connect" call is hot, then it probably means your
cosocket pool is not enabled at all or the configuration is
suboptimal.

> Also I tried to use some database libraries like Tokyo cabinet and SQLite in
> ngx-lua, but they're not useful since you can't close database properly, so
> you're forced to use them as in-memory database.

You need a network layer atop these disk-backed things and make your
Nginx talk to them via cosockets. For example, TokyoTyrant is a
network layer atop TokyoCabinet.

I'm cc'ing the openresty-en mailing list.

Best regards,
-agentzh

jason.dusek

Am 11.02.2013 20:35 schrieb "agentzh" <age...@gmail.com>:
> On Mon, Feb 11, 2013 at 2:42 AM, Onur Bozkurt wrote:
> > Also I tried to use some database libraries like Tokyo cabinet and SQLite in
> > ngx-lua, but they're not useful since you can't close database properly, so
> > you're forced to use them as in-memory database.
>
> You need a network layer atop these disk-backed things and make your
> Nginx talk to them via cosockets. For example, TokyoTyrant is a
> network layer atop TokyoCabinet.

Onur, could you say more about the problems you were
having with closing SQLite properly?

--
Jason Dusek pgp // solidsnack // C1EBC57DC55144F35460C8DF1FD4C6C1FED18A2B