Issue using ngx.location.capture in Lua Module

Legrand Jérémie jeremie.legrand at atos.net
Fri Jan 6 11:01:23 UTC 2012


Hi,

I have a very strange issue with a lua script I use in an access_by_lua_file directive.

In this script, I make two subrequests with ngx.location.capture :

local authRequest = ngx.location.capture("/memc", { args = { key = ngx.var.key } })
local authDatabaseRequest = ngx.location.capture("/postgres", { args = { key = ngx.var.key } })

The first subrequest  goes to location memc defined as follow :

location ~ ^/memc {
    default_type text/plain;
    set $memc_cmd get;
    set $memc_key $arg_key;
    memc_pass memcache;

    #ACL
    internal;
}

It refers to the upstream memcache defined like this :

upstream memcache {
        server 127.0.0.1:11211 max_fails=3 fail_timeout=10s;
}

The second request goes to location postgres :

location /postgres {
    set $key $arg_key;
    postgres_pass database;
    postgres_query "SELECT name
        FROM key k
                                       WHERE mykey = '$key'";
    postgres_output value 0 0;
}

It refers to an upstream database which makes a distant connection to my postgres database :

upstream database {
        postgres_server  my_postgres_adress:5433 dbname=mydbname user=myuser password=mypass;
    }

When I start the nginx server and request something, the lua script does correctly the memcache subrequest but I get this message for the postgres subrequest :

[error] 24631#0: *28 postgres: connection failed: could not send startup packet: Resource temporarily unavailable

If I change the order of subrequests in my script, doing first the postgres subrequest and after the memcache subrequest, there is no error and both subrequests are done successfully.
It seems that the memcached subrequest does not release correctly the connection.

For performance constraints I need to make the memcache request first.

Thanks for help if someone have an idea to resolve this issue.

Jeremie Legrand

________________________________

Ce message et les pièces jointes sont confidentiels et réservés à l'usage exclusif de ses destinataires. Il peut également être protégé par le secret professionnel. Si vous recevez ce message par erreur, merci d'en avertir immédiatement l'expéditeur et de le détruire. L'intégrité du message ne pouvant être assurée sur Internet, la responsabilité d'Atos ne pourra être recherchée quant au contenu de ce message. Bien que les meilleurs efforts soient faits pour maintenir cette transmission exempte de tout virus, l'expéditeur ne donne aucune garantie à cet égard et sa responsabilité ne saurait être recherchée pour tout dommage résultant d'un virus transmis.

This e-mail and the documents attached are confidential and intended solely for the addressee; it may also be privileged. If you receive this e-mail in error, please notify the sender immediately and destroy it. As its integrity cannot be secured on the Internet, the Atos liability cannot be triggered for the message content. Although the sender endeavours to maintain a computer virus-free network, the sender does not warrant that this transmission is virus-free and will not be liable for any damages resulting from any virus transmitted.
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://mailman.nginx.org/pipermail/nginx-devel/attachments/20120106/7cf10977/attachment.html>


More information about the nginx-devel mailing list