Red Hat Bugzilla – Bug 1258879
[RFE] Reduce nova-api load from ceilometer agents with instance metadata caching
Last modified: 2016-04-07 17:05:50 EDT
Currently the ceilometer compute & hardware agents impose much unnecessary load on the nova-api service by querying the instance metadata for every local instance on every polling cycle. This load has caused major problems for operators of ceilometer. The instance metadata is required to decorate the more minimal instance representation retrieved directly from the hypervisor or SNMP, when constructing a classic ceilometer sample (which includes rich snapshotted metadata). However much of this metadata is either static or very infrequently changing, so could easily be cached within the agent. So the nova-api load could be significantly reduced by constraining the nova-api query to only report on the subset of instances for the current node that have changed since the last polling cycle (using the 'changes-since' query parameter).
Verified according test plan. Packages: ceilometer*-5.0.2-1.el7ost.noarch
Since the problem described in this bug report should be resolved in a recent advisory, it has been closed with a resolution of ERRATA. For information on the advisory, and where to find the updated files, follow the link below. If the solution does not work for you, open a new bug report. https://rhn.redhat.com/errata/RHEA-2016-0603.html