exceeding match limit on watchers

[Ivan Mikhaylov]

On Thu, 2019-09-05 at 16:20 +0300, Ivan Mikhaylov wrote:
> Hello everyone!
> 
> Our VESNIN server has a lot of temperature sensors on it, so we tried to
> attach
> watchers via yaml for them. The sd_bus_add_match() returns -105 (ENOBUFS)
> which
> represents exceeding 'some limit', according to the the doc. First of all we
> tried to figure out why it didn't work, and found that match() from sdbusplus
> didn't raise any exception/warning/log, etc. in the event of errors, and just
> passed through silently. I've created an issue for it:
> https://github.com/openbmc/sdbusplus/issues/38 .
> 
> In manpage for sd_bus_add_match() there is no helpful information about
> possible reasons for this over the limit case. I'm trying to figure it out
> from
> systemd code, with little success so far.
> 
> SD_BUS_ERROR_LIMITS_EXCEEDED
>   Some limited resource has been exhausted.
> 
> Maybe anybody knows what and where the limit is and where we can tweak it?
> As far as I can see, there are only ulimit settings In systemd's system.conf.
> 
> Thanks.

dbus-daemon declines request from sd_bus_add_match with ENOBUFS, increasing
"<limit name="max_match_rules_per_connection">1024</limit>" limit via dbus-
1/system.conf helped.