[SR-Users] private memory leak - but where?

[Sebastian Damm]

Thanks Daniel,

looks like that is indeed the case. We the hash table key is the
call-id, but we're not calling $sht(foo=>$ci) but instead passing in
the call-id as a string.

Ich have now written a test script with those two functions:

function handle_packet_bad()
  callId = sr.pv.get("$ci")
  if sr.pv.get("$sht(interceptedSessions=>"..callId..")") ~= nil then
sr.dbg("Lua found matching packet")
  end
end

function handle_packet_good()
  callId = sr.pv.get("$ci")
  sr.pv.sets("$var(htableKey)", callId)
  if sr.pv.get("$sht(interceptedSessions=>$var(htableKey))") ~= nil then
sr.dbg("Lua found matching packet")
  end
end

Then in my Kamailio config, I call one or the other function depending
on whether the PID is odd or even.

        if ($pp & 1) {
                if(!lua_run("handle_packet_bad")) {
                        xlog("L_ERR", "SCRIPT: failed to execute lua
function!\n");
                }
        } else {
                if(!lua_run("handle_packet_good")) {
                        xlog("L_ERR", "SCRIPT: failed to execute lua
function!\n");
                }
        }

Now when I track the "real_mem" used by the UDP listeners, I see the
difference. While the odd PIDs use more and more memory, the even ones
stay about at the same level.

I wouldn't have found that by myself. Thanks again.

Best Regards,
Sebastian

On Wed, Sep 20, 2017 at 10:56 AM, Daniel-Constantin Mierla
<miconda at gmail.com> wrote:
> Hello,
>
> my guess is that you define many cfg variables from lua, which take from
> private memory (their definition).
>
> So $sht(x=>abc) is defined when used first time and kept in memory. If
> you use also $sht(x=>efg), this is another defined variable.
>
> This happens when you do KSR.pv.get("$sht(x=>abc)") or
> KSR.pv.get("$sht(x=>efg)")
>
> To avoid defining a lot of variables, you can do:
>
> KSR.pv.sets("$var(n)", "abc");
> KSR.pv.get("$sht(x=>$var(n)");
> KSR.pv.sets("$var(n)", "efg");
> KSR.pv.get("$sht(x=>$var(n)");
>
> The practically you define only one cfg variable,
> KSR.pv.get("$sht(x=>$var(n)")
>
> The issue is known, there were other reporting it here on the mailing
> list. It's in my to-do before 5.1 to fix it in a way or another, by
> either setting a limit of defined variables and then throw error
> (easier), or track when a variable is used and start deleting the
> definition for older ones when the limit is exceeded.
>
> Cheers,
> Daniel
>
>
>
> On 19.09.17 17:56, Sebastian Damm wrote:
>> Hi Daniel,
>>
>> thanks for the quick response. See my other mail with more details.
>>
>> I don't use cfg variable from the lua script, I only access $shv(...)
>> and $vn(...) or $var(...) and $sht(...) from it. And of course $tU,
>> $hdr(...) and other builtin variables. Some of the variables I'm
>> accessing might not be there always, though ($au for example).
>>
>> Anything I can help with? I only need about half an hour to reproduce it.
>>
>> Best Regards,
>> Sebastian
>>
>> On Tue, Sep 19, 2017 at 5:46 PM, Daniel-Constantin Mierla
>> <miconda at gmail.com> wrote:
>>> Hello,
>>>
>>> do you use kamailio.cfg variables in the lua script? If yes, can you
>>> show how you do it?
>>>
>>> If you have troubles with pkg dump, it should be printed when you
>>> stop/restart. It would be good to do the pkg summary, it is easier to
>>> see the used chunks as a report. There are global parameters to
>>> configure it.
>>>
>>> Cheers,
>>> Daniel
>>>
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>
> --
> Daniel-Constantin Mierla
> www.twitter.com/miconda -- www.linkedin.com/in/miconda
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>