[zeromq-dev] ZeroMQ (2.1.7) subscriber "memory leak"

[john skaller]

On 22/02/2012, at 3:11 AM, Jess Morecroft wrote:

> Hi guys,
> 
> Re the bounds, point taken. We've been taking a process level approach
> to bound monitoring, action triggering (eg. Monit, nagios), which at
> least in this case has allowed us to identify the issue here sooner.
> If messages were silently falling off the back of a queue in certain
> scenarios we may well have not spotted this till much later.

0MQ offers two strategies for overflow:

* BLOCK
* DROP

Perhaps you are asking for a third one:

* TRIGGER

This would be on AHWM (almost high water mark).

so you have time to prevent either BLOCK or DROP.

Default TRIGGER action would be to do nothing.
Example action: log a message and do nothing.
Another action: do a poll to try to clean up. 
Or, of course, read some messages to empty the queues.

No idea how to implement trigger, although a callback
is one option. Another is to send a message to a monitoring
channel.


--
john skaller
skaller at users.sourceforge.net