2:24 p.m.
----- Original Message -----
From: "Heiko W.Rupp" <hrupp(a)redhat.com>
To: "Discussions around Hawkular development"
<hawkular-dev(a)lists.jboss.org>
Sent: Thursday, 4 May, 2017 5:29:30 AM
Subject: [Hawkular-dev] RfC: Layered Hawkular-services vs packaged one
Hey,
right now when we deploy Hawkular-services (H-S) on OpenShift, we run
into a situation where the user may already have deployed
Hawkular-Metrics (HAM) in OpenShift[1] and thus by deploying H-S will
end up in a situation where HAM is deployed twice - once for the
platform and once for H-S.
One solution could be to 'just' deploy H-S in OpenShift instead of HAM,
but this has some drawbacks
- larger deployment
- inclusion of parts that are not needed in 'classic' OpenShift
- different security model for OS-HAM than for H-Services
Another option could be to logically split and layer H-S:
- Have a H-S container (H-S-2) , that does not contain HAM
- This container would provide everything of H-S without HAM
- Calls to H-S-2 HAM are forwarded to OS-HAM
Of course there is no such thing as a free lunch:
- need to reserve the 'hawkular' tenant in OS-Metrics
Sorry for my ignorance, is this just a special tenant that Hawkular Services uses? Is this
just used for internal information that Hawkular Services?
Is it really hard coded to this? or could be change it to something else which would not
conflict with other tenants? eg something like '_hawkular' or
'_hawkular-services'?
- OS-Metrics has a different security concept
H-S-2 could act as a proxy that receives calls to HAM from agents
and clients, but 'translates' credentials and then forwards the calls to
OS-HAM
Does the above idea make any sense?
I am sure I am missing a ton of items in the above list
For me, the bigger issue is around do we want to open up the HAM version we have in
OpenShift to just anything?
Right now we are in control of what goes in here. Its only Heapster and HOSA which can
write metrics, and those are managed by an admin. This allows for the control of how often
metrics and how many metrics are written. Knowing this information, an admin can factor in
how much diskspace they may require.
If we start to open this up to other users to write their own metrics, then I think we
start to run into issues. We don't have an mechanism to only accept so many metric
writes from going into Hawkular Metrics, so it might open things up to using more disk
space than an admin would have originally allocated.
If I am running my own OpenShift cluster, then sure, I might want to allow my own projects
to reuse the internal Hawkular Metrics instance. Its my cluster here running my
components.
But for something like OpenShift Online, where there are separate users all running the
same cluster, I think we would probably want to have checks in place to prevent users from
using up too many of the resources used by the infrastructure components.