[collectd] strange problem with update 5.2.1 to 5.4.1 (rrdc_update ... failed with status -1)

[Sergey]

On Friday 27 June 2014, Sergey wrote:

collectd: rrdtool plugin: rrd_update_r <...>: illegal attempt to update using time 1403869343 when last update time is 1403869343 (minimum one second step)

> This has happened before if more than one collectd was launched.
> But only one launched now...

Now it is associated with ReadThreads somehow. With 5.2.1 I used
"ReadThreads 20" and configuration configuration was stored for
5.4.1. I increase it to 40 and rrdtool plugin began working without
this error. But I could not get working configuration for rrdcached
plugin.

-- 
Regards,
Sergey