The new ops based recovery, introduce as part of #10708, is based on the assumption that all operations below the global checkpoint known to the replica do not need to be synced with the primary. This is based on the guarantee that all ops below it are available on primary and they are equal. Under normal operations this guarantee holds. Sadly, it can be violated when a primary is restored from an old snapshot. At the point the restore primary can miss operations below the replica's global checkpoint, or even worse may have total different operations at the same spot. This PR introduces the notion of a history uuid to be able to capture the difference with the restored primary (in a follow up PR).
The History UUID is generated by a primary when it is first created and is synced to the replicas which are recovered via a file based recovery. The PR adds a requirement to ops based recovery to make sure that the history uuid of the source and the target are equal. Under normal operations, all shard copies will stay with that history uuid for the rest of the index lifetime and thus this is a noop. However, it gives us a place to guarantee we fall back to file base syncing in special events like a restore from snapshot (to be done as a follow up) and when someone calls the truncate translog command which can go wrong when combined with primary recovery (this is done in this PR).
We considered in the past to use the translog uuid for this function (i.e., sync it across copies) and thus avoid adding an extra identifier. This idea was rejected as it removes the ability to verify that a specific translog really belongs to a specific lucene index. We also feel that having a history uuid will serve us well in the future.
At current, we do not feel there is enough of a reason to shade the low
level rest client. It caused problems with commons logging and IDE's
during the brief time it was used. We did not know exactly how many
users will need this, and decided that leaving shading out until we
gather more information is best. Users can still shade the jar
themselves. For information and feeback, see issue #26366.
Closes#26328
This reverts commit 3a20922046.
This reverts commit 2c271f0f22.
This reverts commit 9d10dbea39.
This reverts commit e816ef89a2.
Our documentation for the API is:
```
The _upgrade API is no longer useful and will be removed.
Instead, see Reindex to upgrade.
```
Given that, I don't think we need to test the API anymore.
Closes#25311
This commit updates the version for master to 7.0.0-alpha1. It also adds
the 6.1 version constant, and fixes many tests, as well as marking some
as awaits fix.
Closes#25893Closes#25870
This commit removes all external dependencies from the rest client jar
and shades them in an 'org.elasticsearch.client' package within the jar
using shadowJar gradle plugin. All projects that depended on the
existing jar have been converted to using the 'org.elasticsearch.client'
package prefixes to interact with the rest client.
Closes#25208
OldIndexBackwardsCompatibilityIT#testOldClusterStates tested whether global and index metadata could be read from data directory,
this can also be tested in full cluster qa test that checks cluster state via api.
Relates to #24939
Ports all of RepositoryUpgradabilityIT to qa:full-cluster-restart and ports as much of RestoreBackwardsCompatIT as possible into qa:full-cluster-restart.
The Lucene version constants for 5.4.1 and 5.5.0 are wrong, they are
listed as 6.5.0 instead of 6.5.1. This commit fixes these issues, and
adds a test to ensure that this does not happen again.
Relates #24923
Removes the need for the `_UNRELEASED` suffix on versions by detecting if a version should be unreleased or not based on the versions around it. This should make it simpler to automate the task of adding a new version label.
These tests spin up two nodes of an older version of Elasticsearch,
create some stuff, shut down the nodes, start the current version,
and verify that the created stuff works.
You can run `gradle qa:full-cluster-restart:check` to run these
tests against the head of the previous branch of Elasticsearch
(5.x for master, 5.4 for 5.x, etc) or you can run
`gradle qa:full-cluster-restart:bwcTest` to run this test against
all "index compatible" versions, one after the other. For master
this is every released version in the 5.x.y version *and* the tip
of the 5.x branch.
I'd love to add more to these tests in the future but these
currently just cover the functionality of the `create_bwc_index.py`
script and start to cover the assertions in the
`OldIndexBackwardsCompatibilityIT` test.