disk_free_limit configuration not working as advertised

[Per Bergland]

Hello all,

I can't seem to get the documented ways of setting disk_free_limit to work as is described in the official documentation. This is all when using RMQ 3.5.4.

1. The set_disk_free_limit command documented on https://www.rabbitmq.com/disk-alarms.html does not seem to exist. When I try to invoke it I get a wall of text describing all available commands.

The workaround seems to be to invoke rabbitmqctl eval 'rabbit_disk_monitor:set_disk_free_limit(10000000000).' instead

2. The readable syntax documented on https://www.rabbitmq.com/disk-alarms.html also does not seem to work. When I try the syntax on that page - {disk_free_limit, "1GB"} - I get the stack trace below and the rabbit_disk_monitor subprocess does not start up (but everything else does so it's hard to detect)

Stack trace: [{error_logger_file_h,write_event,

                  [{<0.47.0>,"/var/log/rabbitmq/rab...@vagrant-centos-6.log",

                    []},

                   {error_report,<0.149.0>,

                       {<0.157.0>,supervisor_report,

                        [{supervisor,{local,rabbit_disk_monitor_sup}},

                         {errorContext,start_error},

                         {reason,

                             {badarith,

                                 [{rabbit_disk_monitor,set_disk_limits,2,[]},

                                  {rabbit_disk_monitor,init,1,[]},

                                  {gen_server,init_it,6,

                                      [{file,"gen_server.erl"},{line,328}]},

                                  {proc_lib,init_p_do_apply,3,

                                      [{file,"proc_lib.erl"},{line,240}]}]}},

                         {offender,

                             [{pid,undefined},

                              {name,rabbit_disk_monitor},

                              {mfargs,

                                  {rabbit_disk_monitor,start_link,["1GB"]}},

                              {restart_type,{transient,1}},

                              {shutdown,4294967295},

                              {child_type,worker}]}]}}],

                  [{file,"error_logger_file_h.erl"},{line,114}]},

              {error_logger_file_h,handle_event,2,

                  [{file,"error_logger_file_h.erl"},{line,79}]},

              {rabbit_error_logger_file_h,safe_handle_event,3,[]},

              {gen_event,server_update,4,[{file,"gen_event.erl"},{line,538}]},

              {gen_event,server_notify,4,[{file,"gen_event.erl"},{line,520}]},

              {gen_event,server_notify,4,[{file,"gen_event.erl"},{line,522}]},

              {gen_event,handle_msg,5,[{file,"gen_event.erl"},{line,261}]},

              {proc_lib,init_p_do_apply,3,[{file,"proc_lib.erl"},{line,240}]}]

After this has failed, I get:

sudo rabbitmqctl eval 'rabbit_disk_monitor:set_disk_free_limit(10000000000).'

Error: {noproc,{gen_server,call,

                           [rabbit_disk_monitor,

                            {set_disk_free_limit,10000000000},

                            infinity]}}

Is this because I'm running a too old version of RMQ (it's really not that old) or is the documentation wrong?

Regards,

Per

[Per Bergland]

So it seems that this works in RMQ 3.6.0-1

/Per

[Michael Klishin]

On 4 January 2016 at 12:43:39, Per Bergland (per.be...@meltwater.com) wrote:
> This is all when using RMQ 3.5.4.

Absolute values are not supported in that version:
http://www.rabbitmq.com/changelog.html 
--
MK

Staff Software Engineer, Pivotal/RabbitMQ

[Per Bergland]

Thanks.

Actually, absolute values for disk low watermark work just fine in 3.5.4, just not the abbreviations (like 10GB instead of 10000000000). I could find that the set_disk_free_limit rabbitmqctl command was added in 3.6.0 but not any reference to when the support for human-readable forms was added.

Cheers,

Per

[Michael Klishin]

 On 4 January 2016 at 15:57:13, Per Bergland (per.be...@meltwater.com) wrote:
> Actually, absolute values for disk low watermark work just
> fine in 3.5.4, just not the abbreviations (like 10GB instead
> of 10000000000).

Ah, yes, it's absolute values for RAM that are new-ish.

> I could find that the set_disk_free_limit
> rabbitmqctl command was added in 3.6.0 but not any reference
> to when the support for human-readable forms was added.

In the same release:

https://github.com/rabbitmq/rabbitmq-server/issues/461
https://github.com/rabbitmq/rabbitmq-server/issues/448

[Per Bergland]

Alright thanks Michael!

/Per

--

Per Bergland Engineering Director, Meltwater Gothenburg T: +46 703 42 88 95 per.be...@meltwater.com | www.meltwater.com Twitter  |  LinkedIn  |  Skype:  perbergland Want up to the minute insights? We’ll keep an eye out.