[rabbitmq-discuss] .NET BasicPublish randomly blocks forever

[Matthias Radestock]

Dominik,

domsom wrote:
> On my dev environment (Ubuntu 09.10) running RabbitMQ server 1.6.0-1ubuntu,
> everything runs fine. In the production environment (Debian testing on a
> Virtuozzo virtual server) running RabbitMQ server 1.7.0-3, the Mono
> application (the message publishing thread, to be precise) randomly blocks
> forever when calling BasicPublish.
> [...]
> The log has a lot of entries like these:
> 
> =INFO REPORT==== 24-Jan-2010::15:12:34 ===
>     alarm_handler: {set,{system_memory_high_watermark,[]}}
> 
> =INFO REPORT==== 24-Jan-2010::15:12:35 ===
>     alarm_handler: {clear,system_memory_high_watermark}
> 
> After reading the docs, I figured these errors would cause RabbitMQ telling
> the application to stop sending messages.

That's exactly what is happening and what is causing the publisher to block.

> So I added these parameters to the startup command line:
> -os_mon memory_alarms false -os_mon memsup_system_only false -os_mon
> memsup_system_only false'
> to get rid of them. (In Virtuozzo VMs, it seems there's no way to get a
> valid figure of free memory, so this always triggers.) No effect though, the
> Mono app still blocks.

When you say "no effect", do you mean you still see the alarms?

Can you upgrade to 1.7.1? We changed the memory monitoring in 1.7.1, and 
I don't remember what the options were for controlling it in 1.7.0. The 
new system is documented at http://www.rabbitmq.com/extensions.html#memsup


Regards,

Matthias.