Today when upgrading to the next major version we have a so-called
_major version barrier_: once the cluster comprises nodes of the new
major version then nodes of the previous major version are prevented
from joining the cluster. This means we can be certain that
`clusterState.nodes().getMinNodeVersion().major` will never decrease, so
we can implement upgrade logic that relies on the cluster remaining in
its wholly-upgraded state.
This commit generalises this behaviour to apply to all upgrades, so that
we can be certain that `clusterState.nodes().getMinNodeVersion()` will
never decrease in a running cluster.
Closes#72911
When doing a rolling restart we recommend disabling shard allocation to
avoid unnecessary recoveries. However, this advise is unnecessary or
even harmful when restarting nodes that do not carry any data like a
pure ML node.
Updates the supported upgrade path table in [Upgrade Elasticsearch][0]
to include a new row for maintenance releases. For example, this row
covers upgrading from 7.6.0 to 7.6.2.
The new table row only displays for releases greater than n.x.0. For
example, the new row will display for the 7.7.1 release but not the
7.7.0 release.
[0]: https://www.elastic.co/guide/en/elasticsearch/reference/master/setup-upgrade.html
Remove mention of the `yellow` and `red` starting
health status from the rolling upgrade docs.
Instead, we should emphasize that users wait
for the node to recover with a health status of
`green` rather than the starting status.
Co-authored-by: James Rodewig <james.rodewig@elastic.co>
This change recommends using a regular flush instead of synced-flush in
a rolling upgrade from 7.x to 8.0. We can perform noop recoveries with a
regular flush
The "Restore any snapshots as required" step is a trap: it's somewhere between
tricky and impossible to restore multiple clusters into a single one.
Also add a note about configuring discovery during a rolling upgrade to
proscribe any rare cases where you might accidentally autobootstrap during the
upgrade.
We do mention that rolling back an upgrade requires a restore from a snapshot,
but it's hidden at the bottom of the "preparing to upgrade" instructions on a
different page from the actual upgrade instructions. This commit duplicates the
preparatory instructions onto the pages containing the actual upgrade
instructions and rewords the point about rollbacks a bit.
A few places in the documentation had mentioned 6.7 as the version to
upgrade from, when doing an upgrade to 7.0. While this is technically
possible, this commit will replace all those mentions to 6.8, as this is
the latest version with the latest bugfixes, deprecation checks and
ugprade assistant features - which should be the one used for upgrades.
Co-Authored-By: James Rodewig <james.rodewig@elastic.co>
Adds a note that restarting half-or-more of the master-eligible nodes means
you're no longer doing a rolling upgrade, and may need to upgrade all the
things before the cluster returns to health.
Command needs `?v` so user can see the column headers. Otherwise the instructions in the note about checking the init and relo columns don't make sense
Upgrading the Elastic Stack perfectly documents the process to
upgrade ES from 5 to 6 when internal indices are present. However,
the rolling upgrade docs do not mention anything about internal indices.
This adds a warning in the rolling upgrade procedure, highlighting that
internal indices should be upgraded before the rolling upgrade procedure
can be started.
Tweak the upgrade instructions for moving from pre-6.3-with-x-pack to
post-6.3-default distribution. Specifically, you have to remove the
x-pack plugin before upgrading because 6.4 doesn't understand how to
remove it.
Relates to #34307
Since we disable allocation using persistent settings, we should be consistent and remove
the setting from the persistent storage. Otherwise an accidental restart will lead for shards
not being allocated.
Relates to #28757
James Rodewig
David Turner
Henning Andersen
James Rodewig
Glen Smith
Nhat Nguyen
Marios Trivyzas
Robin Clarke
Alexander Reelsen
DeDe Morton
Lisa Cawley
Boaz Leskes
debadair
Albert Zaharovits
Nik Everett