SASL - duplicate alarms bug

[Francesco Cesarini (Erlang Training & Consulting)]

There used to be an application called EVA, an Event and Alarm Handler, 
which is discontinued and not supported any more. I didn't like it as it 
was too tightly connected to SNMP. I assume others felt the same, as I 
rarely saw others use it.

Francesco


Serge Aleynikov wrote:
> Would it be correct to assume then that barely anyone uses the SASL's 
> alarm_hangler?  If so, what's the reason for leaving it in the OTP, or 
> otherwise, why don't make the basic functionality a bit more usable 
> within the SASL framework?
> 
> Serge
> 
> Francesco Cesarini (Erlang Training & Consulting) wrote:
> 
>> The SASL Alarm handler is a very simple handler, provided to allow 
>> users to get started quickly. Somewhere in the documentation (And in 
>> both our and Ericsson's OTP courses) users are encouraged to develop 
>> their own handler and replace it with a more complex one.
>>
>> Regards,
>> Francesco
>> -- 
>> http://www.erlang-consulting.com
>>
>> Serge Aleynikov wrote:
>>
>>> Is there a reason that the SASL's alarm handler doesn't check for 
>>> duplicate alarms before adding new ones to the list?
>>>
>>> If you do the following on the system with low disk space / free memory:
>>>
>>> 1. Start SASL
>>> 2. Start OS_MON
>>> 3. Stop  OS_MON
>>> 4. Start OS_MON
>>>
>>> you'll get duplicate alarms that are not easily clearled (you'd need 
>>> to call alarm_handler:clear_alarm() multiple times for the same 
>>> AlarmID...
>>>
>>> 17> alarm_handler:get_alarms().
>>> [{system_memory_high_watermark,[]},
>>>  {{disk_almost_full,"/mnt/cdrom"},[]},
>>>  {{disk_almost_full,"/usr"},[]},
>>>  {system_memory_high_watermark,[]},
>>>  {{disk_almost_full,"/mnt/cdrom"},[]},
>>>  {{disk_almost_full,"/usr"},[]}]
>>> 18> alarm_handler:clear_alarm(system_memory_high_watermark).
>>> [{{disk_almost_full,"/mnt/cdrom"},[]},
>>>  {{disk_almost_full,"/usr"},[]},
>>>  {system_memory_high_watermark,[]},
>>>  {{disk_almost_full,"/mnt/cdrom"},[]},
>>>  {{disk_almost_full,"/usr"},[]}]
>>>
>>> This looks like a bug to me.
>>>
>>> Serge
> 
> 
> 
>