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Mod channel doc

This commit is contained in:
Jack Ottofaro
2020-02-07 14:58:48 -05:00
parent 42dacd29a4
commit 1c199f19e0

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@@ -7,89 +7,85 @@
// * updating/updating-disconnected-cluster.adoc
[id="understanding-upgrade-channels_{context}"]
= Understanding {product-title} upgrade channels
= {product-title} Upgrade Channels and Releases
In {product-title} 4.1, Red Hat introduced the concept of upgrade channels for
recommending the appropriate upgrade versions to your cluster. Upgrade channels
separate upgrade strategies and also are used to control the cadence of updates.
Channels are tied to a minor version of {product-title}. For instance,
{product-title} {product-version} channels will never include an upgrade to a
4.5 release. This ensures administrators make an explicit decision to upgrade to
the next minor version of {product-title}. Channels only control updates and
have no impact on the version of the cluster you install; the
`openshift-install` binary for a given patch level of {product-title} always
installs that patch level.
In {product-title} 4.1, Red Hat introduced the concept of channels for
recommending the appropriate release versions for cluster upgrade. By controlling
the pace of upgrades, these upgrade channels allow users to choose an upgrade
strategy. Upgrade channels are tied to a minor version of
{product-title}. For instance, {product-title} {product-version}
upgrade channels will never include an upgrade to a 4.5 release. This ensures
administrators make an explicit decision to upgrade to the next minor version of
{product-title}. Upgrade channels only control release selection and have
no impact on the version of the cluster you install; the `openshift-install`
binary for a given patch level of {product-title} always installs that patch level.
{product-title} {product-version}, which includes the upgrade from the previous 4.3
release, has three upgrade channels to choose from:
{product-title} {product-version} has the following upgrade channels to choose from:
* candidate-{product-version}
* fast-{product-version}
* stable-{product-version}
The upgrade channels contain two types of updates:
[discrete]
== candidate-{product-version} Channel
. General Availability Software (or GA) - These versions of {product-title} are
fully supported and are considered production quality. You may upgrade to the general
availability release from either of the fast and stable channels.
The candidate-{product-version} channel will contain candidate builds for a z-stream
({product-version}.z) release.
Release candidates contain all the features of the product but they are not supported and
should only be used to test feature acceptance and assist in qualifying the next version
of {product-title}.
A release candidate is any build (e.g. 4.3.0-rc.3, 4.3.0) that is available in the candidate
channel.
After a version lands in the candidate channel, it goes through more quality checks and if
it meets the quality standard it is promoted to fast-{product-version} or stable-{product-version}
channels.
So if a given release is available in the candidate-{product-version} channel and also in the fast-{product-version}
or stable-{product-version} channels, it is a Red Hat supported version.
Additionally candidate-{product-version} may include dead end releases from which there are no or ever
be recommended upgrades.
The candidate-{product-version} channel also allows upgrading from a previous minor version of
{product-title} to {product-version}.
. Release Candidate Software (or RC) - These versions of {product-title} are
representative of the eventual general availability release and are available only
in the candidate-{product-version} channel. The release candidate will contain all
the features of the product. You are allowed to upgrade from a release candidate to
another release candidate and to upgrade from a previous minor version of
{product-title} to the current release candidate. Release candidate builds are not
supported by Red Hat and you will not be able to upgrade from a release candidate to
the general availability release of {product-title}. Candidates should be used to
test feature acceptance and assist in qualifying the next version of
{product-title} in your infrastructure.
+
[NOTE]
====
Release candidates differ from the nightly builds found on try.openshift.com. You
cannot upgrade nightly builds to nightly builds. Nightly builds are available for
early access to features but are not upgradable or supported.
Release candidates differ from the nightly builds found on try.openshift.com. Nightly
builds are available for early access to features but updating to or from nightly
builds is neither recommended nor supported. Nightly builds are not avilable in
any upgrade channel.
====
For GA versions, the fast and stable channels present a choice between receiving
updates as soon as they are available or allowing Red Hat to control the rollout of
those updates.
[discrete]
== fast-{product-version} Channel
The fast-{product-version} channel is updated with new {product-version} patch
versions as soon as Red Hat declares the given patch as a general availability
release. As such, these releases are fully supported, are production quality and have
performed well while available as a release candidate in the candidate-{product-version}
channel from where they were promoted. Some time after a release appears in
fast-{product-version} it will also appear in stable-{product-version}. Releases will
never appear in stable-{product-version} before they appear in fast-{product-version}.
The fast-{product-version} channel also allows upgrading from a previous minor version of
{product-title}.
[discrete]
== fast-{product-version}
== stable-{product-version} Channel
The fast channel is updated with new {product-version} patch versions as soon as Red
Hat declares they are generally available. Use this channel if you wish to receive
updates as soon as they are available or for your pre-production environments when
participating in the connected customer program. This channel will contain all
z-stream ({product-version}.z) updates but will not suggest upgrades to the next
minor release (4.5.z) when the next minor release is available.
Like the fast-{product-version} channel, the stable-{product-version} channel will
only contain releases that have been declared general availability are therefore
fully supported. However the stable-{product-version} channel will gradually roll out
releases to customers based on data from our SRE teams, support services, and
pre-production and production environments that participate in our connected customer
program, rather than being immediately available as they are in the fast-{product-version}
channel. For patch and CVE fixes this delay can range from several hours to a day
and allows an extra period of assessment in how the software performs.
The stable-{product-version} channel also allows upgrading from a previous minor version of
{product-title}.
[discrete]
== stable-{product-version}
The stable channel will contain updates on a time delay as they are gradually
rolled out to customers based on data from our SRE teams, support services, and
pre-production and production environments that participate in our connected
customer program, rather than being immediately available as they are in the fast
channel. For patch and CVE fixes this can range from several hours to a day and
allows an extra period of assessment in how the software performs. If issues are
detected during rollout, upgrades to that version may be blocked in both the fast
and stable channels, and a new version may be introduced that will be the new
preferred upgrade target.
Customers can improve this process by configuring pre-production systems on the
fast channel, production systems on the stable channel, and participating in Red
Hats connected customer program - this allows Red Hat to observe the impact of
updates on your specific hardware and software configurations. Future releases may
improve or alter the pace at which updates move from the fast to the stable channels.
If issues are discovered with an upgrade between patch levels, Red Hat may withdraw
that suggested upgrade for affected versions. A newer patch would become available
in the appropriate channels and be suggested for upgrade.
[discrete]
== Upgrade version paths
== Upgrade Version Paths
{product-title} maintains an upgrade recommendation service that understands the
version of {product-title} you have installed as well as the path to take within
@@ -101,19 +97,48 @@ following in the fast-{product-version} channel:
* {product-version}.3
* {product-version}.4
The service only recommends upgrades that have been tested and have no known issues.
The service only recommends upgrades that have been tested and have no serious issues.
If you are on {product-version}.1 and {product-title} is allowing you to select
{product-version}.4, then it is safe for you to go from .{product-version}.1 to .{product-version}.4. Likewise,
the absence of {product-version}.2 may be due to a CVE that was fixed in {product-version}.3 and Red Hat no
longer suggests upgrading to a known vulnerable version. If an issue is found that
results in a new version being retracted from the recommendations, Red Hat will
release a new version that is capable of upgrading from all necessary versions,
including the retracted version.
longer suggests upgrading to a known vulnerable version.
Update stability depends on your channel. The presence of an update recommendation in
the candidate-{product-version} channel does not imply that the update is supported.
It means that no serious issues have been found with the update yet, but there may
not be significant traffic through the update to suggest stability. The presence of
an update recommendation in the fast-{product-version} or stable-{product-version}
channels is a declaration that the update is fully supported while it is in the
channel. While releases will never be removed from a channel, update recommendations
which exhibit serious issues will be removed from all channels. Updates initiated
after the update recommendation has been removed may not be supported.
Red Hat will eventually provide supported update paths from any supported (fast-{product-version}
or stable-{product-version}) release to the latest release in {product-version}.z,
although there may be delays while safe paths away from troubled releases are
constructed and verified.
[discrete]
== Disconnected clusters
== Fast and Stable Channel Usage and Strategies
Customers which have chosen to not be connected to Red Hat and are curating their
The fast-{product-version} and stable-{product-version} channels present a choice between receiving
general availability releases as soon as they are available or allowing Red Hat to
control the rollout of those updates. If issues are detected during rollout or at a
later time, upgrades to that version may be blocked in both the fast-{product-version} and
stable-{product-version} channels, and a new version may be introduced that will be the new
preferred upgrade target.
Customers can improve this process by configuring pre-production systems on the
fast-{product-version} channel, production systems on the stable-{product-version} channel,
and participating in Red Hats xref:../support/remote_health_monitoring/about-remote-health-monitoring.adoc[connected customer program]. This program allows Red
Hat to observe the impact of updates on your specific hardware and software
configurations. Future releases may improve or alter the pace at which updates move
from the fast-{product-version} to the stable-{product-version} channel.
[discrete]
== Restricted Network Clusters
Customers who have chosen to not be connected to Red Hat and are controlling their
own {product-title} container image content manually should consult the Red Hat
errata associated with product releases and note any comments impacting upgrades.
During upgrade the user interface may caution about switching between these versions
@@ -121,10 +146,20 @@ and it is up to the customer to ensure they have correctly selected the appropri
version before bypassing those cautions.
[discrete]
== Switching between channels
== Switching Between Channels
It is supported for customers to switch between the fast and stable channel at any
time. Channels only offer suggested upgrades, and will never suggest a dangerous
upgrade. If you switch to the candidate channel after installing from a GA version,
you will see a warning the current version is not recognized, and you can safely
switch back to a GA channel.
It is supported for customers to switch from the stable-{product-version} channel to
the fast-{product-version} at any time. Customers can also switch to the
candidate-{product-version} at any time but should be aware that some releases in the
candidate-{product-version} channel may be release candidates and therefore not
supported. A customer can switch from candidate-{product-version} to fast-{product-version}
if their current release is a general availability release. Customers can always
switch from fast-{product-version} to stable-{product-version}, although there may
be a delay of up to a day if their current release was recently promoted to
fast-{product-stable} while they wait for the release to be promoted to
stable-{product-version}. If you change to a channel that does not include your
current release, an alert will fire, no updates will be recommended, and you can
safely change back to your original channel at any point.
Please refer to the <<candidate-{product-version} Channel>> section above to understand the
distinction between a release candidate and a general avilability release.