SASL - duplicate alarms bug

Serge Aleynikov <>
Wed Aug 3 14:34:24 CEST 2005


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




More information about the erlang-questions mailing list