[SR-Users] memcache problem - reporting protocol error

Fri Jun 7 13:07:00 CEST 2013

Hi Dragos,

Yes, that should work fine.

Cheers,

Charles
On 7 Jun 2013 12:00, "Dragos Oancea" <droancea at yahoo.com> wrote:

> Hi Charles,
>
> Thank you for the information. These details are good to know.
> Do you think it's safe to use the new module from git with kamailio-4.0.0 ?
> I mean just copying it in the kamailio-4.0.0 source tree, compiling it and
> then putting it in the modules directory to be loaded at runtime.
>
>
> Regards,
> Dragos
>
>   ------------------------------
>  *From:* Charles Chance <charles.chance at sipcentric.com>
> *To:* Dragos Oancea <droancea at yahoo.com>
> *Cc:* SIP Router - Kamailio (OpenSER) and SIP Express Router (SER) -
> Users Mailing List <sr-users at lists.sip-router.org>
> *Sent:* Friday, June 7, 2013 11:06 AM
> *Subject:* Re: [SR-Users] memcache problem - reporting protocol error
>
> The main difference, other than the new library, is the ability to specify
> an expiry for each stored key/value at the time of setting it:
>
> So now there are two ways to set a value:
>
> $mct(key) = value; (default expiry will be used as per module param)
>
> or the new way, $mct(key=>expiry) = value;
>
>
> Currently, the module still only supports a single memcache server,
> although if you are looking for a distributed solution, we have tested
> Couchbase/Moxi and it works really well.
>
> All the best,
>
> Charles
>
>
> On 6 June 2013 20:40, Dragos Oancea <droancea at yahoo.com> wrote:
>
> Hi Charles,
>
> Thank you for your answer.
> I've notice that your name shows in the headers of the files of the new
> (patched) memcached module.
> Can you please detail a little bit on what does your patch bring new apart
> from libmemcached support ?
> Or what does it still miss, since you said it's under heavy development.
>
> Many thanks!
>
> Regards,
> Dragos
>
>   ------------------------------
>  *From:* Charles Chance <charles.chance at sipcentric.com>
> *To:* Dragos Oancea <droancea at yahoo.com>
> *Cc:* SIP Router - Kamailio (OpenSER) and SIP Express Router (SER) -
> Users Mailing List <sr-users at lists.sip-router.org>
> *Sent:* Thursday, June 6, 2013 7:37 PM
>
> *Subject:* Re: [SR-Users] memcache problem - reporting protocol error
>
> Although it's difficult to know the exact cause of your "protocol" error,
> it does appear from your tests that the graceful handling of errors and
> subsequent reconnects is better in libmemcached than in libmemcache. So if
> you do encounter the same conditions again, I would imagine that the
> library would handle it and attempt to reconnect transparently.
> If not, however, then at least you are more likely to find support as the
> library is still under active development :)
> Cheers,
> Charles
>  On 6 Jun 2013 18:12, "Dragos Oancea" <droancea at yahoo.com> wrote:
>
> Hi Charles,
>
> I tried first to trigger again the bug using some iptables rules (to
> simulate a network problem) , so Kamailio could not communicate with the
> memcache anymore:
>
>  WARNING: memcached [memcached.c:189]: WARNING: memcached:
> mcm_server_readable():2582: timeout: select(2) call timed out for
> read(2)able fds
> WARNING: memcached [memcached.c:189]: WARNING: memcached:
> mcm_server_writable():3173: timeout: write select(2) call timed out
> WARNING: memcached [memcached.c:189]: WARNING: memcached:
> mcm_server_connect():2290: select(2) failed: select(2) timed out on
> establishing conn
> ection
> NOTICE: memcached [memcached.c:194]: NOTICE: memcached:
> mcm_server_connect():2297: connect(2) failed
> NOTICE: memcached [memcached.c:194]: NOTICE: memcached:
> mcm_server_connect_next_avail():2323: unable to find a server to connect to
>
> This looks very much like what i've seen in the logs just before it
> started to report the "protocol error" problem.
>
> But in the simulated case , after I remove the iptables rules that block
> the access to memcache, Kamailo does not recover from the situation, it
> just keeps on printing messages like the above, when it should
> connect to memcache instead. It looks like another libmemcache-related bug
> to me.
>
> Then I tried the same thing with  the latest memcached module from git:
> With the memcached firewalled after starting Kamailio it prints this to
> the logs:
>
> ERROR: memcached [mcd_var.c:154]: pv_get_mcd_value_helper(): could not get
> result for
> key 29515_HA1 - error was 'SERVER HAS FAILED AND IS DISABLED UNTIL TIMED
> RETRY'
>
> When I flush the firewall rules, it reconnects to memcache, which makes it
> better than the old one.
> But how can I be sure that the new one will not have the same "protocol
> error" issue, since I could not reproduce exactly the problem so far ?
>
>
> Regards,
> Dragos
>
>
>
>   ------------------------------
>  *From:* Charles Chance <charles.chance at sipcentric.com>
> *To:* Dragos Oancea <droancea at yahoo.com>; Kamailio (SER) - Users Mailing
> List <sr-users at lists.sip-router.org>
> *Sent:* Thursday, June 6, 2013 6:27 PM
> *Subject:* Re: [SR-Users] memcache problem - reporting protocol error
>
> Hi Dragos,
>
> The memcached module has indeed been updated in the master to use
> libmemcached, as the old libmemcache library is no longer under active
> development. Have you tried using the latest version of the module from
> git? Do you still get the same errors?
>
> Cheers,
>
> Charles
>
>
> On 6 June 2013 16:18, Dragos Oancea <droancea at yahoo.com> wrote:
>
> Hello
>
>
> We are having issues with the memcached module (Kamailio 4.0.0) .
>
>
> All of a sudden we are getting this kind of messages in the logs, and the
> values for the requested keys are not retrieved.
>
>
> ALERT: memcached [memcached.c:189]: ALERT: memcached:
> mcm_fetch_cmd():1305: memcache(4) protocol error: STORED#015#012VALUE
> 29515_HA1 0
> 32#015#012b52299247f16c6adfa4c8cc53b34e74a#015#012END#015#012STORED#015#012
> [...]
> ALERT: memcached [memcached.c:189]: ALERT: memcached:
> mcm_fetch_cmd():1176: memcache(4) protocol error: server sent data for key
> not in request
>
>
> I suspect that at some point there was a network problem between the
> memcached server and Kamailio that triggered this abnormal behavior and I
> also suspect that it is
> connected with the (old) libmemcache library (libmemcache-1.4.0.rc2) .
>
>
> This is fixed only with a Kamailio restart.
>
>
> Has anyone experience this ?  Is there a fix ?
> I noticed that the Kamailio from the trunk compiles the memcached module
> with the more new libmemcached library from here:
> https://launchpad.net/libmemcached/+download .
> Maybe this is one of the reasons libmemcache is going to be dropped ?
>
> Thank you very much.
>
> Regards,
> Dragos
>
>
>
>
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> Sipcentric Ltd. Company registered in England & Wales no. 7365592. Registered
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> B7 4EJ.
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> office: Unit 10 iBIC, Birmingham Science Park, Holt Court South, Birmingham
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