28 May
2020
28 May
'20
7:19 p.m.
Thank you both for the attention and the feedbacks
Point clarified, it should be a new algorithms, something like :
“13” - location optimized routing mode, the lowest latency gets higher
priority (serial forking ordered by priority, ds_ping_latency_stats is
required).
The main drawback it that there is not load balancing, I would like to
address this now, by making it configurable, an option to activate location
optimized with load balancing routing mode.
I would like to find a clear and simple way to do this, that should be easy
to document and understand.
For example in a scenario like that, it would be best that gateways with
similar latency would get traffic load balanced to them, the priority could
be overloaded to represent the threshold :
I found this simple formula : *ADJUSTED_PRIORITY = PRIORITY -
(ROUNDDOWN(ESTIMATED_LATENCY/PRIORITY))*
Priority is also the threshold for latency priority adjustment, not sure if
overloading it is creating confusion, in this example gateway 1, 4 and 6
would receive 33%/33%/33%, the other gateways would be only there for
failover
GATEWAY PRIORITY ESTIMATED_LATENCY ADJUSTED_PRIORITY
1 30 21 30
2 30 91 27
3 30 61 28
4 30 19 30
5 30 32 29
6 30 0 30
7 30 201 24
On Thu, May 28, 2020 at 9:08 AM Daniel-Constantin Mierla <miconda(a)gmail.com>
wrote:
Hello,
maybe a dedicated module is going to be too complex or better said,
duplicate a lot of code for management of the destinations,
load/reload/keepalive, ... (although I won't have anything against such
approach, if considered better by developer).
However, if done in dispatcher, I think that a new algorithm id should be
used, leaving 8 as it is. Also, there should be a new field added in the
internal structure to keep this "dynamic" priority -- it can be initialized
to the "priority" value.
In some cases I use different algorithms for the same group of
destinations, so it would be good to be able to use algorithm 8 with
priority from database and the new algorithm at the same time.
Cheers,
Daniel
On 27.05.20 21:46, Henning Westerholt wrote:
Hi Julien,
sounds interesting, a “location optimized routing mode”. What about making
it as a dedicated mode, to not overloading the mode “8”?
Cheers,
Henning
--
Henning Westerholt – https://skalatan.de/blog/
Kamailio services – https://gilawa.com
*From:* sr-dev <sr-dev-bounces(a)lists.kamailio.org>
<sr-dev-bounces(a)lists.kamailio.org> *On Behalf Of *Julien Chavanton
*Sent:* Thursday, May 14, 2020 7:26 PM
*To:* Kamailio (SER) - Development Mailing List
<sr-dev(a)lists.kamailio.org> <sr-dev(a)lists.kamailio.org>rg>; Kamailio (SER) -
Users Mailing List <sr-users(a)lists.kamailio.org>
<sr-users(a)lists.kamailio.org>
*Subject:* [sr-dev] congestion control priority for priority based
dispatching
Hi Folks,
Just found another simple use case of the dispatcher latency stats.
Just shraing this idea of a feature I want to contribute.
When using dispatcher algorithm 8:
“8” - select destination sorted by priority attribute value (serial
forking ordered by priority).
If the gateway as the attribute, the priority becomes the estimated
latency.
cc-priority
- The dispatcher would automatically prioritize the closest one.
- If a gateway is becoming unresponsive it will automatically become de
prioritize.
Consider this real life scenario where you have gateways in East and West
Coast
Example
URI: sip:28.71.19.140
FLAGS: AP
PRIORITY: 10
ATTRS: {
BODY: cc_priority=1
}
LATENCY: {
AVG: 84.001000
STD: 0.062000
EST: 84.001000 (high == low priority)
MAX: 93
TIMEOUT: 0
URI: sip:28.71.16.140
FLAGS: AP
PRIORITY: 10
ATTRS: {
BODY: cc_priority=1
}
LATENCY: {
AVG: 29.110000
STD: 2.383000
EST: 31.999000 (low == high priority)
MAX: 1499
TIMEOUT: 1
Another major improvement to all of this would be to gather stats on
INVITE <> 100 to have a very accurate latency estimation even if the
gateway does not support SIP OPTIONS pings
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--
Daniel-Constantin Mierla -- www.asipto.comwww.twitter.com/miconda --
www.linkedin.com/in/miconda
Funding: https://www.paypal.me/dcmierla
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