This commit introduces sequence-number-based recovery. When a replica
has fallen out of sync, rather than performing a file-based recovery we
first attempt to replay operations since the last local checkpoint on
the replica. To do this, at the start of recovery the replica tells the
primary what its local checkpoint is. The primary will then wait for all
operations between that local checkpoint and the current maximum
sequence number to complete; this is to ensure that there are no gaps in
the operations that will be replayed from the primary to the
replica. This is a best-effort attempt as we currently have no
guarantees on the primary that these operations will be available; if we
are not able to replay all operations in the desired range, we just
fallback to file-based recovery. Later work will strengthen the
guarantees.
Relates #22484
`ToXContentObject` extends `ToXContent` without adding new methods to it, while allowing to mark classes that output complete xcontent objects to distinguish them from classes that require starting and ending an anonymous object externally.
Ideally ToXContent would be renamed to ToXContentFragment, but that would be a huge change in our codebase, hence we simply document the fact that toXContent outputs fragments with no guarantees that the output is valid per se without an external ancestor.
Relates to #16347
* Remove a checked exception, replacing it with `ParsingException`.
* Remove all Parser classes for the yaml sections, replacing them with static methods.
* Remove `ClientYamlTestFragmentParser`. Isn't used any more.
* Remove `ClientYamlTestSuiteParseContext`, replacing it with some static utility methods.
I did not rewrite the parsers using `ObjectParser` because I don't think it is worth it right now.
Sequence BWC logic consists of two elements:
1) Wire level BWC using stream versions.
2) A changed to the global checkpoint maintenance semantics.
For the sequence number infra to work with a mixed version clusters, we have to consider situation where the primary is on an old node and replicas are on new ones (i.e., the replicas will receive operations without seq#) and also the reverse (i.e., the primary sends operations to a replica but the replica can't process the seq# and respond with local checkpoint). An new primary with an old replica is a rare because we do not allow a replica to recover from a new primary. However, it can occur if the old primary failed and a new replica was promoted or during primary relocation where the source primary is treated as a replica until the master starts the target.
1) Old Primary & New Replica - this case is easy as is taken care of by the wire level BWC. All incoming requests will have their seq# set to `UNASSIGNED_SEQ_NO`, which doesn't confuse the local checkpoint logic (keeping it at `NO_OPS_PERFORMED`)
2) New Primary & Old replica - this one is trickier as the global checkpoint service currently takes all in sync replicas into consideration for the global checkpoint calculation. In order to deal with old replicas, we change the semantics to say all *new node* in sync replicas. That means the replicas on old nodes don't count for the global checkpointing. In this state the seq# infra is not fully operational (you can't search on it, because copies may miss it) but it is maintained on shards that can support it. The old replicas will have to go through a file based recovery at some point and will get the seq# information at that point. There is still an edge case where a new primary fails and an old replica takes over. I'lll discuss this one with @ywelsch as I prefer to avoid it completely.
This PR also re-enables the BWC tests which were disabled. As such it had to fix any BWC issue that had crept in. Most notably an issue with the removal of the `timestamp` field in #21670.
The commit also includes a fix for the default value of the seq number field in replicated write requests (it was 0 but should be -2), that surface some other minor bugs which are fixed as well.
Last - I added some debugging tools like more sane node names and forcing replication request to implement a `toString`
There is not yet a BWC layer in sequence numbers. This commit sets the
BWC version to 6.0.0 for the BWC and rolling upgrade tests until this
BWC layer is built.
This commit enables real BWC testing against a 5.1 snapshot. All
REST tests plus rolling upgrade test now run against a mixed version
cross major version cluster.
At one point in the past when moving out the rest tests from core to
their own subproject, we had multiple test classes which evenly split up
the tests to run. However, we simplified this and went back to a single
test runner to have better reproduceability in tests. This change
removes the remnants of that multiplexing support.
This makes it obvious that these tests are for running the client yaml
suites. Now that there are other ways of running tests using the REST
client against a running cluster we can't go on calling the shared
client yaml tests "REST tests". They are rest tests, but they aren't
**the** rest tests.
This adds a header that looks like `Location: /test/test/1` to the
response for the index/create/update API. The requirement for the header
comes from https://www.w3.org/Protocols/rfc2616/rfc2616-sec10.htmlhttps://tools.ietf.org/html/rfc7231#section-7.1.2 claims that relative
URIs are OK. So we use an absolute path which should resolve to the
appropriate location.
Closes#19079
This makes large changes to our rest test infrastructure, allowing us
to write junit tests that test a running cluster via the rest client.
It does this by splitting ESRestTestCase into two classes:
* ESRestTestCase is the superclass of all tests that use the rest client
to interact with a running cluster.
* ESClientYamlSuiteTestCase is the superclass of all tests that use the
rest client to run the yaml tests. These tests are shared across all
official clients, thus the `ClientYamlSuite` part of the name.
Change version, required a minor fix in the RPM building.
In case of a alpha/beta version, the release will contain alpha/beta
as the RPM version cannot contains dashes/tildes.
This change adds the infrastructure to run the rest tests on a multi-node
cluster that users 2 different minor versions of elasticsearch. It doesn't implement
any dedicated BWC tests but rather leverages the existing REST tests.
Since we don't have a real version to test against, the tests uses the current version
until the first minor / RC is released to ensure the infrastructure works.
Relates to #14406Closes#17072
Jason Tedor
Ali Beyad
javanna
Nik Everett
Boaz Leskes
Simon Willnauer
Ryan Ernst
Clinton Gormley
Adrien Grand
Alexander Reelsen