Collapsing connections 3.3.1-dev

[Vladyslav Bachynskyi <v....@gmail.com>]

Hi All,

I want to use connection collapsing in my current configuration, but I'm
not sure, is it stable at the moment?

My current version:
Apache Traffic Server - traffic_server - 3.3.1-dev - (build # 11318 on
Dec  3 2012 at 18:52:55)

What else except proxy.config.cache.enable_read_while_writer and
background_fill_completed_threshold, would you recommend to configure in
case of configuration with connection collapsing.

Thanks,

Re: Collapsing connections 3.3.1-dev

[Vladyslav Bachynskyi <v....@gmail.com>]

Thanks, Leif.

What I'm looking for is a feature to make wait some time cache requests
for some object if this object has been requested and transferring from
the origin at this moment.
In my current configuration I can see situations when I have couple of
requests to the same object at the same time, and all these requests
directs to origin, as requested object is not in cache yet.

On 15.04.2013 17:50, Leif Hedstrom wrote:
> On 4/15/13 7:58 AM, Vladyslav Bachynskyi wrote:
>> Hi All,
>>
>> I want to use connection collapsing in my current configuration, but
>> I'm not sure, is it stable at the moment?
>
> I think the connection collapsing feature was removed long ago. It was
> deemed unstable, and unmaintainable. I don't think anyone is or plan
> on working on it, but we certainly would accept such contributions :).
>
>>
>> My current version:
>> Apache Traffic Server - traffic_server - 3.3.1-dev - (build # 11318
>> on Dec  3 2012 at 18:52:55)
>>
>> What else except proxy.config.cache.enable_read_while_writer and
>> background_fill_completed_threshold, would you recommend to configure
>> in case of configuration with connection collapsing.
>
> read-while-writer, and the fuzzy "pre-revalidate" feature are both
> there to alleviate the stampeding herd problem. The latter lets you
> configure a "chance" for a client request to not be served out of
> cache, but instead go to origin. You tell it when to start doing this,
> and what the percentage chance is (e..g 5 minutes before expiration,
> and 0.1% chance).
>
> -- Leif
>
>
>

Re: Collapsing connections 3.3.1-dev

[Leif Hedstrom <zw...@apache.org>]

On 4/15/13 7:58 AM, Vladyslav Bachynskyi wrote:
> Hi All,
>
> I want to use connection collapsing in my current configuration, but I'm 
> not sure, is it stable at the moment?

I think the connection collapsing feature was removed long ago. It was 
deemed unstable, and unmaintainable. I don't think anyone is or plan on 
working on it, but we certainly would accept such contributions :).

>
> My current version:
> Apache Traffic Server - traffic_server - 3.3.1-dev - (build # 11318 on 
> Dec  3 2012 at 18:52:55)
>
> What else except proxy.config.cache.enable_read_while_writer and 
> background_fill_completed_threshold, would you recommend to configure in 
> case of configuration with connection collapsing.

read-while-writer, and the fuzzy "pre-revalidate" feature are both there to 
alleviate the stampeding herd problem. The latter lets you configure a 
"chance" for a client request to not be served out of cache, but instead go 
to origin. You tell it when to start doing this, and what the percentage 
chance is (e..g 5 minutes before expiration, and 0.1% chance).

-- Leif