Module not working, but simple Cache::Memcached request does

[zoot]

Hi David

I'm unable to get this module to work with Dancer2.

This Perl code read/writes to my Memcached instance perfectly:

#!/usr/bin/perl

use Cache::Memcached;

my $memd = Cache::Memcached->new();
$memd->set_servers(['/path/to/sessions.sock']);

print "set fruit=orange\n";
$memd->set('fruit', 'orange');

my $val = $memd->get('fruit');
printf("get fruit: %s\n", $val);

print "delete 'fruit'\n";
$memd->delete('fruit');

my $val = $memd->get('fruit');
printf("get fruit: %s\n", $val);

My Dancer2 app sessions work fine with:

session: Simple

or

session: JSON

but NOT with:

session: Memcached

engines:
  session:
    Memcached:
      memcached_servers: /path/to/sessions.sock

I ran both the test code above and the Dancer2 app as the same user, so definitely no permission issues there.

How can I debug this? I see Dancer2::Session::Memcached uses the same module as my stand-alone test script does (Cache::Memcached) so wondering why it doesn't work?

Dancer2 0.03
Dancer2::Session::Memcached 0.002

You mentioned that in D2, session destruction should be done using

context->destroy_session

Am I also supposed to use different session syntax when setting and getting session variables, when using this session module?

I'm using:

session user => 'zoot'; # set session variable
my $user = session('user'); # get session variable

[dagolden]

Hi, Dale. Could you send me a stripped down application that demonstrates the problem? I'm going to ship a new Dancer2::Session::Memcached that fixes some test bugs, but I don't think they affect your case.

[zoot]

Thanks David

Here's an easy to install package to create the same environment I'm using.

wget http://filegooi.co.za/get2/984a80022b945e6981ac0f7bb8b82409/dancer2-json-vs-memcached-sessions.tar.gz
tar xzf dancer2-json-vs-memcached-sessions.tar.gz
cd demo
vim README
./install.sh

[zoot]

Sorry, there's a minor typo in the install script. This fixes it:

http://filegooi.co.za/get2/e374d9f89c10a0f464e6669b7903afc1/dancer2-json-vs-memcached-sessions.tar.gz

[zoot]

Here are details on Tokyo Tyrant's protocols:

http://fallabs.com/tokyotyrant/spex.html#protocol

More specifically, it states, about Memcached:

As for the memcached (ASCII) compatible protocol, the server implements the following commands; "set", "add", "replace", "get", "delete", "incr", "decr", "stats", "flush_all", "version", and "quit". "noreply" options of update commands are also supported. However, "flags", "exptime", and "cas unique" parameters are ignored.

[dagolden]

Thanks. I can't get TT running on my Mac, so I'm getting a Linux VM in
shape to try it.

Have you tried regular memcached, not TT? It would be nice to know if it's
a general problem or a TT specific.

David

On Wed, Apr 10, 2013 at 7:13 PM, Dale Gallagher [email protected]:

Sorry, there's a minor typo in the install script. This fixes it:

http://filegooi.co.za/get2/e374d9f89c10a0f464e6669b7903afc1/dancer2-json-vs-memcached-sessions.tar.gz

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[zoot]

No, I haven't tried stock standard memcached. I doubt it's TT, as per my regular test script in that bundle, using Cache::Memcached works as expected. Are there perhaps certain commands other than those supported by TT, above, required/used? I'll give vanilla memcached a whirl to test compatibility.

[zoot]

Ok, some progress. I installed memcached and tested my demo app with it, using both ascii and binary proto and it works! The confusing thing though, is how the module Cache::Memcached actually works when speaking memcached proto to TT and Dancer2::Session::Memcached is using it! Any idea? This bug is hiding.

False alarm, two memcached instances were running. D2:S:M only runs when memcached is set to use the ascii protocol. Errors like the following occur when using binary protocol:

Invalid magic: 67
<27 connection closed.
<27 new binary client connection.
<27 Read binary protocol data:
<27 0x67 0x65 0x74 0x20
<27 0x55 0x57 0x68 0x61
<27 0x62 0x66 0x50 0x42
<27 0x74 0x46 0x37 0x55
<27 0x35 0x71 0x66 0x6f
<27 0x63 0x73 0x76 0x6f
Invalid magic: 67
<27 connection closed.

[dagolden]

That's really strange. All the plugin does is dispatch to the
Cache::Memcached object. The only think I could imagine could be different
could be context, maybe, but I'm really not sure.

David

On Fri, Apr 12, 2013 at 7:42 PM, Dale Gallagher [email protected]:

Ok, some progress. I installed memcached and tested my demo app with it,
using both ascii and binary proto and it works! The confusing thing though,
is how the module Cache::Memcached actually works when speaking memcached
proto to TT and Dancer2::Session::Memcached is using it! Any idea? This bug
is hiding.

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Reply to this email directly or view it on GitHubhttps://github.com//issues/1#issuecomment-16310148
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David Golden [email protected]
Take back your inbox! → http://www.bunchmail.com/
Twitter/IRC: @xdg