openstack-manuals/doc/arch-design/hybrid/section_operational_considerations_hybrid.xml
Alexandra Settle 3336a7a5a3 Removal of passive voice from chap 7, arch guide
Removal of passive voice from section_operational_considerations

Change-Id: I4bdcd925e2829ed59de802c2b1c840ca5f9bec83
Partial-bug: #1429696
2015-03-12 12:11:36 +10:00

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<?xml version="1.0" encoding="UTF-8"?>
<section xmlns="http://docbook.org/ns/docbook"
xmlns:xi="http://www.w3.org/2001/XInclude"
xmlns:xlink="http://www.w3.org/1999/xlink"
version="5.0"
xml:id="arch-guide-hybrid-operational-considerations">
<?dbhtml stop-chunking?>
<title>Operational considerations</title>
<para>Hybrid cloud deployments present complex operational
challenges. There are several factors to consider that affect
the way each cloud is deployed and how users and operators
will interact with each cloud. Each cloud provider implements
infrastructure components differently. This can lead to incompatible
interactions with workloads, or a specific Cloud Management
Platform (CMP). Different cloud providers may
also offer different levels of integration with competing
cloud offerings.</para>
<para>Monitoring is an important aspect to consider when selecting
a CMP. Gaining valuable insight into each
cloud is critical to gaining a holistic view of all involved
clouds. It is vital to determine whether an existing CMP supports
monitoring of all the clouds involved, or if compatible APIs
are available to be queried for necessary information.
Gather all the information about each cloud, you can now take
appropriate actions on the offline data to avoid impacting workloads.</para>
<section xml:id="agility">
<title>Agility</title>
<para>The implemention of a hybrid cloud solution provides application
availability across different cloud environments and
technologies. This availability enables the deployment to
survive disaster in any single cloud environment.
Each cloud should provide the means to quickly spin up new
instances in the case of capacity issues or complete
unavailability of a single cloud installation.</para>
</section>
<section xml:id="application-readiness-hybrid">
<title>Application readiness</title>
<para>It is important to understand the type of application
workload that is to be deployed across a hybrid cloud environment.
Enterprise workloads that depend on the
underlying infrastructure for availability are not designed to
run on OpenStack. Although these types of applications can run
on an OpenStack cloud, if the application is not able to
tolerate infrastructure failures, it is likely to require
significant operator intervention to recover. However, cloud
workloads are designed to handle fault tolerance. The SLA
of the application is not tied to the underlying
infrastructure. Ideally, cloud applications are designed
to recover when entire racks and even data centers full of
infrastructure experience an outage.</para>
</section>
<section xml:id="upgrades">
<title>Upgrades</title>
<para>If the deployment includes a public cloud, predicting
upgrades may not be possible. Examine the advertised SLA for
any public cloud provider being used.</para>
<note>
<para>At massive scale, even when
dealing with a cloud that offers an SLA with a high percentage
of uptime, workloads must be able to recover at short
notice.</para>
</note>
<para>When upgrading private cloud deployments, care
must be taken to minimize disruption by making incremental
changes and providing a facility to either rollback or
continue to roll forward when using a continuous delivery
model.</para>
<para>Upgrades to the CMP may need to be completed in coordination
with any of the hybrid cloud upgrades. This is necessary
whenever API changes are made.</para>
</section>
<section xml:id="network-operation-center-noc">
<title>Network Operation Center</title>
<para>It is important to recognize control over infrastructure particulates
when planning the Network Operation Center (NOC)
for a hybrid cloud environment. If a significant
portion of the cloud is on externally managed systems,
prepare for situations where it may not be possible to
make changes.
Additionally, situations of conflict may arise in which
multiple providers have differing points of view on the way
infrastructure must be managed and exposed. This can lead to
delays in root cause and analysis where each insists the blame
lies with the other provider.</para>
<para>It is important to ensure that the structure put in place
enables connection of the networking of both clouds to form an
integrated system, keeping in mind the state of handoffs.
These handoffs must both be as reliable as possible and
include as little latency as possible to ensure the best
performance of the overall system.</para>
</section>
<section xml:id="maintainability">
<title>Maintainability</title>
<para>Operating hybrid clouds is a situation in which there is a
greater reliance on third party systems and processes. As a
result of a lack of control of various pieces of a hybrid
cloud environment, it is not possible to guarantee
proper maintenance of the overall system. Instead, the user
must be prepared to abandon workloads and spin them up again
in an improved state. Having a hybrid cloud deployment does,
however, provide agility for these situations by allowing the
migration of workloads to alternative clouds in response to
cloud-specific issues.</para>
</section>
</section>