[collectd] jcollectd dispatches type_instance values with length more than 64 characters

[Amit Gupta]

Hi,

I have configured jcollectd to collect the statistics of the servlets
deployed on tomcat. I have added the following xml element in the
tomcat-jcollectd.xml (shipped with jcollectd) to achieve the same:-

<mbean name="Catalina:j2eeType=Servlet,*" alias="SERVLET">
      <attribute name="attr-name" alias="alias-name" type="counter"/>
</mbean>

The collectd is configured to received data from collectd as
documented in the jcollectd page. I am getting the required statistics
for most of the servlets, however statistics for few of them aren't
getting published (i.e rrd files for some of the servlets aren't
getting created). The collectd logs says the following:-
network plugin: parse_part_string: Output buffer too small.

The issue here seems to be with the length of the type_instance
dispatched by jcollectd for some of the servlets. i.e the length is
more than 64 characters (type_instance is being constructed using the
mbean object name pattern which for some of the sevlets is more than
64 characters). The collectd documentation clearly suggests that the
length of these types should be less than 64 characters. Note from the
documentation:
"Please note that the char-arrays have a fixed size of
DATA_MAX_NAME_LEN (currently 64). Don't let this buffer overflow! "

Is there any particular reason to limit the length of type_instance to
64 characters?.

Regards
Amit