[erlang-questions] Problematic SSL message publication

Ryan Brown <>
Wed Sep 25 23:28:02 CEST 2013


Thank you Ingela. I will work on creating a test to compare to openssl.

In the mean time, what we are currently doing is this. Our application
sends requests to various hosts via ibrowse (http/s). The messages are
basic HTTP  form POSTs (application/x-www-form-urlencoded). Our test just
sends these messages to our application which pops them on a queue in
RabbitMQ then one-by-one pulls them off and attempt to deliver them. Fairly
straightforward really.

Best,

Ryan



On Wed, Sep 25, 2013 at 2:59 PM, Ingela Andin <> wrote:

> Hi!
>
> On Wed, Sep 25, 2013 at 7:07 PM, Ryan Brown <> wrote:
>
>> Excellent Ingela! By upgrading to the R!6B02 we have been able to
>> eliminate the above stated issue with the Erlang message queues growing.
>> However, we are still seeing VERY slow throughput to ssl endpoints. In our
>> limited, scaled-back, test. We are seeing message throughput to an ssl
>> endpoint at 12 msgs/sec and non-ssl of 300+ msgs/sec. Is there a connection
>> limit for ssl connections related to Erlang directly?
>>
>> Thank you!
>>
>>
>>
> Could you send me more details how you are performing this test. It would
> be interesting if I could run the same kind of test as you do. And when you
> say messages what more exactly do mean? Messages can be on many abstraction
> levels (tcp messages, tls messages, http messages etc).  Could you perform
> the same kind of throughput test running for instance openssl?
>
> Regards Ingela Erlang/OTP team - Ericsson AB
>
>
>
>
>>
>> On Wed, Sep 25, 2013 at 6:58 AM, Ingela Andin <>wrote:
>>
>>> Hi!
>>>
>>>
>>> 2013/9/25 Ryan Brown <>
>>>
>>>> Hi Ingela,
>>>>
>>>> Thank you for the response. I suppose I don't really know how to see
>>>> what messages are in the ssl queue. What I am looking at is nregs and
>>>> watching the "msgs" column growing at a steady pace. Is there a way to look
>>>> at these messages?
>>>>
>>>>
>>> You can use the observer application to look at erlang processes.
>>>
>>> http://www.erlang.org/erldoc?q=observe&x=0&y=0
>>>
>>>
>>>
>>>> As for reproducing in the latest version of ssl. I was planning on
>>>> upgrading a machine to 16 today and attempting to reproduce. This should
>>>> get me the latest ssl version correct?
>>>>
>>>>
>>> R16B02  (ssl-5.3.1) is the latest. There is a bug in ssl-5.1 (R15B02)
>>> version (fix in ssl5.2) that perhaps could be related to your problem.
>>>
>>> Regards Ingela Erlang/OTP Team - Ericsson AB
>>>
>>>
>>> On Wed, Sep 25, 2013 at 2:09 AM, Ingela Andin <>wrote:
>>>
>>>>
>>>> Hi!
>>>>
>>>>  2013/9/24 Ryan Brown <>
>>>>
>>>>> We have a fairly high-volume (28m+ messages/day) application that
>>>>> works, essentially, as a pub-sub for many internal and external
>>>>> applications. We are experiencing an issue under load where and subscribers
>>>>> that are using ssl are experiencing a significant slowness in delivery.
>>>>> When we restart the server we begin watching the processes in our
>>>>> application and we can, very reliably and fairly quickly, see the
>>>>> ssl_manager_sup process message queue start increasing in size. As this
>>>>> happens, all messages for those subscribers with ssl endpoints begin to
>>>>> back-up and delivery slows to a near halt.
>>>>>
>>>>>
>>>> What messages are there in the queue?
>>>>
>>>>
>>>>  It appears that ssl is a bit of a known issue within erlang. Or, at
>>>>> least, a tricky use-case to perfect. Are there any known issues that we can
>>>>> address in terms of configuration, best practices in setting-up ssl
>>>>> connections or anything else for that matter we can be doing to resolve
>>>>> this issue or more clearly identify the root cause? We're in active
>>>>> troubleshooting mode and doing what we can to dig deeper including
>>>>> dissecting the code to the kernel.
>>>>>
>>>>> We are running Erlang 15B02 (64bit).
>>>>>
>>>>>
>>>>>
>>>> So that would be ssl-5.1?  Is it possible to reproduce the problem on
>>>> the latest version ?
>>>>
>>>> Regards Ingela Erlang/OTP team - Ericsson AB
>>>>
>>>
>>>
>>>
>>>  --
>>>> -rb
>>>>
>>>
>>>
>>
>>
>> --
>> -rb
>>
>
>


-- 
-rb
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