Re: JSON PMDA

[fche at redhat dot com (Frank Ch. Eigler)]

dsmith wrote:


> Here's a pointer to the latest version of the JSON PMDA I'm working on. 
> [...]

Looks great!

> I've also attached 2 sample systemtap scripts:
>
> - net_xmit_json.stp: A script written by Will Cohen to monitor network
> transmit counts and latency
>
> - netfilter_summary_json.stp: I took an existing systemtap sample script
> (netfilter_summary.stp) and converted it to output JSON instead.

May I recommend also taking a peek at some of the other stap examples,
for consideration of json variantification?  For example, a script
collecting backtrace samples/profiles, I/O traces (kind of like the
last-100-frees glibc sample, but for some kernel tracepoints?), could
be neat, as it is hard to achieve in pcp without stap.
 

> [...]
> - Debug an issue with the PMDA where the command to get the ceph data is
> run too often.

(Do you need to run __load_[all_]json_data before an actual fetch for
metrics with the affected prefixes?  Loading/refreshing metadata is
bound to be less costly than loading actual data.)


> - Try this with other JSON data sources. Suggestions welcome.

How about ovirt?  It may need another python metadata-generator script
(to pass along hostname / authentication / vm-enumeration into the
data-exec command)
http://www.ovirt.org/REST-Api 
https://bugzilla.redhat.com/show_bug.cgi?id=1182275

How about jboss/wildfly?  Same need re. metadata-generation.
https://docs.jboss.org/author/display/WFLY8/The+HTTP+management+API?_sscc=t


- FChE