[OpenSIPS-Users] Not enough memory to sync cluster data

[Răzvan Crainea]

On 12/6/18 1:16 PM, Vitalii Aleksandrov wrote:
> 
>> This seems to be more clean, efficient, and if you don't need it, the 
>> OS will not even allocate it (due to the demand-paging mechanism). So 
>> I don't see where you reservations for setting a higher value of the 
>> -M parameter come from.
>>
>> Best regards,
>> Răzvan
>>
> Just my 2 cents about PKG mem. Indeed OS will not allocate all requested 
> PKG mem at the strartup. After a while if sync mechanism continues to 
> work continuously all worker processes will be involved at least once in 
> a syncing process (send or receive big amount of data). That means that 
> all processes will try to init that memory and OS will finally map 
> requested virtual memory to psychical one. When the sync is finished and 
> after pkg_free() called that memory becomes free and reusable from the 
> process point of view, but if I recall correctly how the memory manager 
> works (at least worked in kamailio) those chunks will be just marked as 
> free in internal data structure but never returned back to the OS. To 
> make long story short in the end after a while OS will have to really 
> allocate RAM for all opensips worker processes if all of them are 
> involved in proto_bin processing (not sure about it).
> Please correct me if I'm wrong.
> 

Hi, Vitalii!

You are absolutely right! However, syncing is not such a frequent 
process, it is only done either during a restart of the backup server, 
or if an MI command triggers it, not sure why, but most likely also due 
to a restart of the backup server. So I'd argue only a bunch of sync 
commands will be used per run, but indeed, these might occur in any process.

@Alexei, getting back to the original error, can point us the exact 
error that made you think about usrloc sync-ing? I am asking because 
during sync, usrloc data is sent in smaller chunks, not the entire table 
at once. Therefore your assumption might be a bit misleading.

Best regards,

-- 
Răzvan Crainea
OpenSIPS Core Developer
   http://www.opensips-solutions.com
Meet the OpenSIPS team at the next OpenSIPS Summit:
   https://www.opensips.org/events