Backport support for replicating closed indices (#39499)
Before this change, closed indexes were simply not replicated. It was therefore
possible to close an index and then decommission a data node without knowing
that this data node contained shards of the closed index, potentially leading to
data loss. Shards of closed indices were not completely taken into account when
balancing the shards within the cluster, or automatically replicated through shard
copies, and they were not easily movable from node A to node B using APIs like
Cluster Reroute without being fully reopened and closed again.
This commit changes the logic executed when closing an index, so that its shards
are not just removed and forgotten but are instead reinitialized and reallocated on
data nodes using an engine implementation which does not allow searching or
indexing, which has a low memory overhead (compared with searchable/indexable
opened shards) and which allows shards to be recovered from peer or promoted
as primaries when needed.
This new closing logic is built on top of the new Close Index API introduced in
6.7.0 (#37359). Some pre-closing sanity checks are executed on the shards before
closing them, and closing an index on a 8.0 cluster will reinitialize the index shards
and therefore impact the cluster health.
Some APIs have been adapted to make them work with closed indices:
- Cluster Health API
- Cluster Reroute API
- Cluster Allocation Explain API
- Recovery API
- Cat Indices
- Cat Shards
- Cat Health
- Cat Recovery
This commit contains all the following changes (most recent first):
* c6c42a1 Adapt NoOpEngineTests after #39006
* 3f9993d Wait for shards to be active after closing indices (#38854)
* 5e7a428 Adapt the Cluster Health API to closed indices (#39364)
* 3e61939 Adapt CloseFollowerIndexIT for replicated closed indices (#38767)
* 71f5c34 Recover closed indices after a full cluster restart (#39249)
* 4db7fd9 Adapt the Recovery API for closed indices (#38421)
* 4fd1bb2 Adapt more tests suites to closed indices (#39186)
* 0519016 Add replica to primary promotion test for closed indices (#39110)
* b756f6c Test the Cluster Shard Allocation Explain API with closed indices (#38631)
* c484c66 Remove index routing table of closed indices in mixed versions clusters (#38955)
* 00f1828 Mute CloseFollowerIndexIT.testCloseAndReopenFollowerIndex()
* e845b0a Do not schedule Refresh/Translog/GlobalCheckpoint tasks for closed indices (#38329)
* cf9a015 Adapt testIndexCanChangeCustomDataPath for replicated closed indices (#38327)
* b9becdd Adapt testPendingTasks() for replicated closed indices (#38326)
* 02cc730 Allow shards of closed indices to be replicated as regular shards (#38024)
* e53a9be Fix compilation error in IndexShardIT after merge with master
* cae4155 Relax NoOpEngine constraints (#37413)
* 54d110b [RCI] Adapt NoOpEngine to latest FrozenEngine changes
* c63fd69 [RCI] Add NoOpEngine for closed indices (#33903)
Relates to #33888
* Rename integTest to bwcTestSample for bwc test projects
This change renames the `integTest` task to `bwcTestSample` for projects
testing bwc to make it possible to run all the bwc tests that check
would run without running on bwc tests.
This change makes it possible to add a new PR check on backports to make
sure these don't break BWC tests in master.
* Rename task as per PR
This commit adds the 7.1 version constant to the 7.x branch.
Co-authored-by: Andy Bristol <andy.bristol@elastic.co>
Co-authored-by: Tim Brooks <tim@uncontended.net>
Co-authored-by: Christoph Büscher <cbuescher@posteo.de>
Co-authored-by: Luca Cavanna <javanna@users.noreply.github.com>
Co-authored-by: markharwood <markharwood@gmail.com>
Co-authored-by: Ioannis Kakavas <ioannis@elastic.co>
Co-authored-by: Nhat Nguyen <nhat.nguyen@elastic.co>
Co-authored-by: David Roberts <dave.roberts@elastic.co>
Co-authored-by: Jason Tedor <jason@tedor.me>
Co-authored-by: Alpar Torok <torokalpar@gmail.com>
Co-authored-by: David Turner <david.turner@elastic.co>
Co-authored-by: Martijn van Groningen <martijn.v.groningen@gmail.com>
Co-authored-by: Tim Vernum <tim@adjective.org>
Co-authored-by: Albert Zaharovits <albert.zaharovits@gmail.com>
We have had various reports of problems caused by the maxRetryTimeout
setting in the low-level REST client. Such setting was initially added
in the attempts to not have requests go through retries if the request
already took longer than the provided timeout.
The implementation was problematic though as such timeout would also
expire in the first request attempt (see #31834), would leave the
request executing after expiration causing memory leaks (see #33342),
and would not take into account the http client internal queuing (see #25951).
Given all these issues, it seems that this custom timeout mechanism
gives little benefits while causing a lot of harm. We should rather rely
on connect and socket timeout exposed by the underlying http client
and accept that a request can overall take longer than the configured
timeout, which is the case even with a single retry anyways.
This commit removes the `maxRetryTimeout` setting and all of its usages.
This PR removes the temporary change we made to the yml test harness in #37285
to automatically set `include_type_name` to `true` in index creation requests
if it's not already specified. This is possible now that the vast majority of
index creation requests were updated to be typeless in #37611. A few additional
tests also needed updating here.
Additionally, this PR updates the test harness to set `include_type_name` to
`false` in index creation requests when communicating with 6.x nodes. This
mirrors the logic added in #37611 to allow for typeless document write requests
in test set-up code. With this update in place, we can remove many references
to `include_type_name: false` from the yml tests.
Today we pass `discovery.zen.minimum_master_nodes` to nodes started up in
tests, but for 7.x nodes this setting is not required as it has no effect.
This commit removes this setting so that nodes are started with more realistic
configurations, and deprecates it.
This commit restores a noop version of the AllFieldMapper that is instanciated only
for indices created in 6x. We need this metadata field mapper to be present in this version
in order to allow the upgrade of indices that explicitly disable _all (enabled: false).
The mapping of these indices contains a reference to the _all field that we cannot remove
in 7 so we'll need to keep this metadata mapper in 7x. Since indices created in 6x will not
be compatible with 8, we'll remove this noop mapper in the next major version.
Closes#37429
The integ tests currently use the raw zip project name as the
distribution type. This commit simplifies this specification to be
"default" or "oss". Whether zip or tar is used should be an internal
implementation detail of the integ test setup, which can (in the future)
be platform specific.
Added warnings checks to existing tests
Added “defaultTypeIfNull” to DocWriteRequest interface so that Bulk requests can override a null choice of document type with any global custom choice.
Related to #35190
In Lucene 8 searches can skip non-competitive hits if the total hit count is not requested.
It is also possible to track the number of hits up to a certain threshold. This is a trade off to speed up searches while still being able to know a lower bound of the total hit count. This change adds the ability to set this threshold directly in the track_total_hits search option. A boolean value (true, false) indicates whether the total hit count should be tracked in the response. When set as an integer this option allows to compute a lower bound of the total hits while preserving the ability to skip non-competitive hits when enough matches have been collected.
Relates #33028
* Deprecate types in index API
- deprecate type-based constructors of IndexRequest
- update tests to use typeless IndexRequest constructors
- no yaml tests as they have been already added in #35790
Relates to #35190
Moves all remaining (rolling-upgrade and mixed-version) REST tests to use Zen2. To avoid adding
extra configuration, it relies on Zen2 being set as the default discovery type. This required a few
smaller changes in other tests. I've removed AzureMinimumMasterNodesTests which tests Zen1
functionality and dates from a time where host providers were not configurable and each cloud
plugin had its own discovery.type, subclassing the ZenDiscovery class. I've also adapted a few tests
which were unnecessarily adding addTestZenDiscovery = false for the same legacy reasons. Finally,
this also moves the unconfigured-node-name REST test to Zen2, testing the auto-bootstrapping
functionality in development mode when no discovery configuration is provided.
This commit changes the format of the `hits.total` in the search response to be an object with
a `value` and a `relation`. The `value` indicates the number of hits that match the query and the
`relation` indicates whether the number is accurate (in which case the relation is equals to `eq`)
or a lower bound of the total (in which case it is equals to `gte`).
This change also adds a parameter called `rest_total_hits_as_int` that can be used in the
search APIs to opt out from this change (retrieve the total hits as a number in the rest response).
Note that currently all search responses are accurate (`track_total_hits: true`) or they don't contain
`hits.total` (`track_total_hits: true`). We'll add a way to get a lower bound of the total hits in a
follow up (to allow numbers to be passed to `track_total_hits`).
Relates #33028
* DISCOVERY: Fix RollingUpgradeTests
* Don't manually manage min master nodes if not necessary
* Remove some dead code
* Allow for manually supplying list of seed nodes
* Closes#35178
With this change, `Version` no longer carries information about the qualifier,
we still need a way to show the "display version" that does have both
qualifier and snapshot. This is now stored by the build and red from `META-INF`.
The java yaml test runner supports sending request headers, yet not all clients support headers. This commit makes sure that we enforce adding a skip section with feature "headers" whenever headers are used in a do section as part of a test. That decreases the chance for new tests to break client builds due to the missing skip section.
Closes#34650
#33708 introduced a strict deprecation mode that makes a REST request
fail if there is a warning header in the response returned by
Elasticsearch (usually a deprecation message signaling that a feature
or a field has been deprecated).
This change adds the strict deprecation mode into the REST integration
tests, and makes the tests fail if a deprecated feature is used. Also
any test using a deprecated feature has been modified to pass the build.
The YAML integration tests already analyzed HTTP warnings so they do
not use this mode, keeping their "expected vs actual" behavior.
Today we index the same number of documents (50 documents) in each round
of the rolling upgrade tests. If the actual count does not match, we can
not guess the problematic round.
Relates #27650
If a shard was serving as a replica when another shard was promoted to
primary, then its Lucene index was reset to the global checkpoint.
However, if the new primary fails before the primary/replica resync
completes and we are now being promoted, we have to restore the reverted
operations by replaying the translog to avoid losing acknowledged writes.
Relates #33473
Relates #32867
In #29623 we added `Request` object flavored requests to the low level
REST client and in #30315 we deprecated the old `performRequest`s. This
changes all calls in the `qa/rolling-upgrade` project to use the new
versions.
Although the master branch does not affect by #31482, it's helpful to
have BWC tests that verify the peer recovery with a synced-flush index.
This commit adds the bwc tests from #31506 to the master branch.
Relates #31482
Relates #31506
Use all running nodes as unicast seeds in the rolling restart tests to
avoid a race between pinging and the tests. Without this if the tests
are too fast then when a new node comes up and pings its single
configured seed node that node *might* not have a ping from the other
running node.
This is much more realistic and can find more issues. This causes the
"mixed cluster" tests to be run twice so I had to fix the tests to work
in that case. In most cases I did as little as possible to get them
working but in a few cases I went a little beyond that to make them
easier for me to debug while getting them to work. My test changes:
1. Remove the "basic indexing" tests and replace them with a copy of the
tests used in the OSS. We have no way of sharing code between these two
projects so for now I copy.
2. Skip the a few tests in the "one third" upgraded scenario:
* creating a scroll to be reused when the cluster is fully upgraded
* creating some ml data to be used when the cluster is fully ugpraded
3. Drop many "assert yellow and that the cluster has two nodes"
assertions. These assertions duplicate those made by the wait condition
and they fail now that we have three nodes.
4. Switch many "assert green and that the cluster has two nodes" to 3
nodes. These assertions are unique from the wait condition and, while
I imagine they aren't required in all cases, now is not the time to
find that out. Thus, I made them work.
5. Rework the index audit trail test so it is more obvious that it is
the same test expecting different numbers based on the shape of the
cluster. The conditions for which number are expected are fairly
complex because the index audit trail is shut down until the template
for it is upgraded and the template is upgraded when a master node is
elected that has the new version of the software.
6. Add some more information to debug the index audit trail test because
it helped me figure out what was going on.
I also dropped the `waitCondition` from the `rolling-upgrade-basic`
tests because it wasn't needed.
Closes#25336
A rolling upgrade from oss Elasticsearch to the default distribution of
Elasticsearch is significantly different than a full cluster restart to
install a plugin and is again different from starting a new cluster with
xpack installed. So this adds some basic tests to make sure that the
rolling upgrade that enables xpack works at all.
This also removes some unused imports from the tests that I modified in
PR #30728. I didn't mean to leave them.
Switches the rolling upgrade tests from upgrading two nodes to upgrading
three nodes which is much more realistic and much better able to find
unexpected bugs. It upgrades the nodes one at a time and runs tests
between each upgrade. As such this now has four test runs:
1. Old
2. One third upgraded
3. Two thirds upgraded
4. Upgraded
It sets system properties so the tests can figure out which stage they
are in. It reuses the same yml tests for the "one third" and "two
thirds" cases because they are *almost* the same case.
This rewrites the yml-based indexing tests to be Java based because the
yml-based tests can't handle different expected values for the counts.
And the indexing tests need that when they are run twice.
Applying the rest test gradle plugin already uses the zip distribution
by default, so specifying it explicitly is not necessary. These are
leftovers from before zip was the default for rest tests.
Nodes are reusing task ids after restart. So in some rare circumstances
the same task id might be assigned to the reindexing task stored by the
old cluster and the new task that is trying to retrieve the task
results. As a result, the get task request can timeout waiting on
itself. Since we already waited for the task to finish before restarting
the cluster, waiting for the task here doesn't make any sense to start
with.
Fixes#28732
Generalizing BWC building so that there is less code to modify for a release. This ensures we do not
need to think about what major or minor version is in the gradle code. It follows the general rules of the
elastic release structure. For more information on the rules, see the VersionCollection's javadoc.
This also removes the additional bwc snapshots that will never be released, such as 6.0.2, which were
being built and tested against every time we ran bwc tests.
Additionally, it creates 4 new projects that correspond to the different types of snapshots that may exist
for a given version. Its possible to now run those individual tasks to work out bwc logic whereas
previously it was impossible and the entire suite of bwc tests had to be run to work out any logic
changes in the build tools' bwc project. Please note that if the project does not make sense for the
version that is current, that an error will be thrown from that individual project if an attempt is made to
run it.
This should allow for automating the version bumps as well, since it removes all the hardcoded version
logic from the configs.
The configuration of the upgraded cluster task was missing a dependency
on the stopping of the second old node in the cluster. In some cases
(e.g., --parallel) Gradle would then try to run the configuration of a
node in the upgraded cluster before it had even configured the old nodes
in the cluster.
Relates #28036
extract all clauses from a conjunction query.
When clauses from a conjunction are extracted the number of clauses is
also stored in an internal doc values field (minimum_should_match field).
This field is used by the CoveringQuery and allows the percolator to
reduce the number of false positives when selecting candidate matches and
in certain cases be absolutely sure that a conjunction candidate match
will match and then skip MemoryIndex validation. This can greatly improve
performance.
Before this change only a single clause was extracted from a conjunction
query. The percolator tried to extract the clauses that was rarest in order
(based on term length) to attempt less candidate queries to be selected
in the first place. However this still method there is still a very high
chance that candidate query matches are false positives.
This change also removes the influencing query extraction added via #26081
as this is no longer needed because now all conjunction clauses are extracted.
https://www.elastic.co/guide/en/elasticsearch/reference/6.x/percolator.html#_influencing_query_extractionCloses#26307
Today all these API calls have a sideeffect of making documents visible
to search requests. While this is sometimes desired it's an unnecessary sideeffect
and now that we have an internal (engine-private) index reader (#26972) we artificially
add a refresh call for bwc. This change removes this sideeffect in 7.0.
The rolling-upgrade test was only writing the "minimum_master_nodes" setting to the configuration file of the old nodes, but not the upgraded ones.
Also changes the value of "minimum_master_nodes" from "number_of_nodes" to "(number_of_nodes / 2) + 1".
The ensure green approach to avoid allocation delays caused problems with other indices created by other tests which didn't use ensure green in the various cluster stages. This aligns testHistoryUUIDIsGenerated to use the same approach used by the other test.
This commit increases the amount of time to wait for green to accound for unassigned shards that
have been delayed. The default delay is 60s, so we need to wait longer than that. Previously, the
wait would timeout at 30s due to the rest client and the default for the cluster health api.
Closes#26742
The test starts with two old nodes and creates indices (without waiting for green, which is fixed here too). Then it restarts one of the nodes and waits for it to join the cluster. This wait condition only uses wait for yellow as our generic infra doesn't how many nodes are there in total. Once the restarted node is part of the cluster (mixed mode) the second old node is restarted. If indices are not fully allocated when that happens, the shards will go into delayed unassigned mode. If the recovery of the replica never completed we may end up with corrupted / no secondary copy on the node. This will cause the shards to be delayed for 1m before being reassigned and the test will time out.
Restoring a shard from snapshot throws the primary back in time violating assumptions and bringing the validity of global checkpoints in question. To avoid problems, we should make sure that a shard that was restored will never be the source of an ops based recovery to a shard that existed before the restore. To this end we have introduced the notion of `histroy_uuid` in #26577 and required that both source and target will have the same history to allow ops based recoveries. This PR make sure that a shard gets a new uuid after restore.
As suggested by @ywelsch , I derived the creation of a `history_uuid` from the `RecoverySource` of the shard. Store recovery will only generate a uuid if it doesn't already exist (we can make this stricter when we don't need to deal with 5.x indices). Peer recovery follows the same logic (note that this is different than the approach in #26557, I went this way as it means that shards always have a history uuid after being recovered on a 6.x node and will also mean that a rolling restart is enough for old indices to step over to the new seq no model). Local shards and snapshot force the generation of a new translog uuid.
Relates #10708Closes#26544
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 a rolling upgrade test for scripting that is totally
busted yet is preventing builds from succeeding. We elect to remove this
test as opposed to skipping the test as:
- it has beeen being skipped for months with no apparent loss
- it appears to need significant work to get to an unbusted state
In the rolling upgrade tests, there is a test to create an index with
replica shards and ensure that in the mixed cluster environment, the
cluster health is green before any other tests are executed. However,
there were two problems with this. First, if the replica shard was
residing on the restarted node, then delayed allocation will kick in and
cause the cluster health request to timeout after 1m. The fix to this
was to drastically lower the delayed allocation setting. Second, if the
primary exists on the higher version node, then the replica cannot be
assigned to the lower version node because recovery cannot happen from
lower lucene versions. The fix here was to wait for the cluster health
to be yellow instead of green in the mixed cluster environment. In the
fully upgraded cluster, the cluster health check waits for a green
cluster as before.
Closes#25185
In 6.x we prevent multiple types and default to `index.mapping.single_type: false`
This change removes the registered setting and ensures that it's preserved for
5.x indices.
Relates to #24961
This commit adds a gradle project, set inside the root build.gradle,
which controls all our bwc tests. This allows for seamless (ie no errant
CI failures) backporting of behavior.
In #25201, a setting was added to allow setting the retry timeout for the rest client under the
impression that this would allow requests to go longer than 30s. However, there is also a socket
timeout that needs to be set to greater than 30s, which this change adds a setting for.
This commit adds a setting to change the request timeout for the rest client. This is useful as the
default timeout is 30s, which is also the same default for calls like cluster health. If both are
the same then the response from the cluster health api will not be received as the client usually
times out first making test failures harder to debug.
Relates #25185
This commit adds back "id" as the key within a script to specify a
stored script (which with file scripts now gone is no longer ambiguous).
It also adds "source" as a replacement for "code". This is in an attempt
to normalize how scripts are specified across both put stored scripts and script usages, including search template requests. This also deprecates the old inline/stored keys.
We default to 0 replicas in the rolling restart scenario already to ensure
we test against worst case. Yet, this adds a dummy index to ensure we also
recover and index with replicas just fine.
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.
This commit changes the rolling upgrade test to create a set of rest
test tasks per wire compat version. The most recent wire compat version
is always tested with the `integTest` task, and all versions can be
tested with `bwcTest`.
This commit expands the logic for version extraction from Version.java
to include a list of all versions for backcompat purposes. The tests
using bwcVersion are converted to use this list, but those tests
(rolling upgrade and backwards-5.0) are still not randomized; that will
happen in another followup.
This commit renames all rest test files to use the .yml extension
instead of .yaml. This way the extension used within all of
elasticsearch for yaml is consistent.
In #24251 we fix an issue with stored search templates that
this test would have discovered: stored search templates cause
the node to refuse to start. Technically a "restart" test would
have caught this as well and would have caught it more quickly.
But we already *have* an upgrade test and we don't have restart tests.
And testing this on upgrade is a good thing too.
This change simplifies how the rest test runner finds test files and
removes all leniency. Previously multiple prefixes and suffixes would
be tried, and tests could exist inside or outside of the classpath,
although outside of the classpath never quite worked. Now only classpath
tests are supported, and only one resource prefix is supported,
`/rest-api-spec/tests`.
closes#20240
After splitting integ tests into cluster configuration and the test
runner task, we still have dependencies of the test runner added as deps
of the cluster. This commit adds dependencies directly to the cluster,
so that the runner can have other dependencies independent of what is
needed for the cluster.
We currently have the last minor version of the previous major hardcoded
in tests like rolling upgrade. This change programatically finds this
during gradle initialization by parsing versions from Version.java.
Gradle's finalizedBy on tasks only ensures one task runs after another,
but not immediately after. This is problematic for our integration tests
since it allows multiple project's integ test clusters to be
simultaneously. While this has not been a problem thus far (gradle 2.13
happened to keep the finalizedBy tasks close enough that no clusters
were running in parallel), with gradle 3.3 the task graph generation has
changed, and numerous clusters may be running simultaneously, causing
memory pressure, and thus generally slower tests, or even failure if the
system has a limited amount of memory (eg in a vagrant host).
This commit reworks how integ tests are configured. It adds an
`integTestCluster` extension to gradle which is equivalent to the current
`integTest.cluster` and moves the rest test runner task to
`integTestRunner`. The `integTest` task is then just a dummy task,
which depends on the cluster runner task, as well as the cluster stop
task. This means running `integTest` in one project will both run the
rest tests, and shut down the cluster, before running `integTest` in
another project.
This commit enforces the requirement of Content-Type for the REST layer and removes the deprecated methods in transport
requests and their usages.
While doing this, it turns out that there are many places where *Entity classes are used from the apache http client
libraries and many of these usages did not specify the content type. The methods that do not specify a content type
explicitly have been added to forbidden apis to prevent more of these from entering our code base.
Relates #19388
Currently, stored scripts use a namespace of (lang, id) to be put, get, deleted, and executed. This is not necessary since the lang is stored with the stored script. A user should only have to specify an id to use a stored script. This change makes that possible while keeping backwards compatibility with the previous namespace of (lang, id). Anywhere the previous namespace is used will log deprecation warnings.
The new behavior is the following:
When a user specifies a stored script, that script will be stored under both the new namespace and old namespace.
Take for example script 'A' with lang 'L0' and data 'D0'. If we add script 'A' to the empty set, the scripts map will be ["A" -- D0, "A#L0" -- D0]. If a script 'A' with lang 'L1' and data 'D1' is then added, the scripts map will be ["A" -- D1, "A#L1" -- D1, "A#L0" -- D0].
When a user deletes a stored script, that script will be deleted from both the new namespace (if it exists) and the old namespace.
Take for example a scripts map with {"A" -- D1, "A#L1" -- D1, "A#L0" -- D0}. If a script is removed specified by an id 'A' and lang null then the scripts map will be {"A#L0" -- D0}. To remove the final script, the deprecated namespace must be used, so an id 'A' and lang 'L0' would need to be specified.
When a user gets/executes a stored script, if the new namespace is used then the script will be retrieved/executed using only 'id', and if the old namespace is used then the script will be retrieved/executed using 'id' and 'lang'
This is related to #22116. URLRepository requires SocketPermission
connect. This commit introduces a new module called "repository-url"
where URLRepository will reside. With the new module, permissions can
be removed from core.
* Fix Translog.Delete serialization for sequence numbers
Translog.Delete used `.writeVLong` instead of `.writeLong` for the sequence
number and primary term (and their respective "read" variants). This could lead
to issues where a 5.x node sent a translog operation with a negative sequence
number (-2 for unassigned seq no) that tripped an assertion serializing a
negative number and causing ES to exit.
Adds a unit test for serialization and a mixed-cluster REST test, since that was
how this was originally caught.
* Use more realistic values for random seqNum and primary term
* Add comment with TODO for removal in 7.0
* Change comment into an assert
* 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.