This commit enables the use of TLSv1.3 with security by enabling us to
properly map `TLSv1.3` in the supported protocols setting to the
algorithm for a SSLContext. Additionally, we also enable TLSv1.3 by
default on JDKs that support it.
An issue was uncovered with the MockWebServer when TLSv1.3 is used that
ultimately winds up in an endless loop when the client does not trust
the server's certificate. Due to this, SSLConfigurationReloaderTests
has been pinned to TLSv1.2.
Closes#32276
Scheduler.schedule(...) would previously assume that caller handles
exception by calling get() on the returned ScheduledFuture.
schedule() now returns a ScheduledCancellable that no longer gives
access to the exception. Instead, any exception thrown out of a
scheduled Runnable is logged as a warning.
This is a continuation of #28667, #36137 and also fixes#37708.
Replaces intermediate geo objects built by ShapeBuilders with
objects from the libs/geo hierarchy. This should allow us to build
all geo functionality around a single hierarchy.
Follow up for #35320
* Remove empty statements
There are a couple of instances of undocumented empty statements all across the
code base. While they are mostly harmless, they make the code hard to read and
are potentially error-prone. Removing most of these instances and marking blocks
that look empty by intention as such.
* Change test, slightly more verbose but less confusing
The default value for ssl.supported_protocols no longer includes TLSv1
as this is an old protocol with known security issues.
Administrators can enable TLSv1.0 support by configuring the
appropriate `ssl.supported_protocols` setting, for example:
xpack.security.http.ssl.supported_protocols: ["TLSv1.2","TLSv1.1","TLSv1"]
Relates: #36021
* Testing conventions now checks for tests in main
This is the last outstanding feature of the old NamingConventionsTask,
so time to remove it.
* PR review
This commit introduces a NetworkMessage class. This class has two
subclasses - InboundMessage and OutboundMessage. These messages can
be serialized and deserialized independent of the transport. This allows
more granular testing. Additionally, the serialization mechanism is now
a simple Supplier. This builds the framework to eventually move the
serialization of transport messages to the network thread. This is the
one serialization component that is not currently performed on the
network thread (transport deserialization and http serialization and
deserialization are all on the network thread).
Currently we create dedicated network threads for both the http and
transport implementations. Since these these threads should never
perform blocking operations, these threads could be shared. This commit
modifies the nio-transport to have 0 http workers be default. If the
default configs are used, this will cause the http transport to be run
on the transport worker threads. The http worker setting will still exist
in case the user would like to configure dedicated workers. Additionally,
this commmit deletes dedicated acceptor threads. We have never had these
for the netty transport and they can be added back if a need is
determined in the future.
This introduces a new ssl-config library that can parse
and validate SSL/TLS settings and files.
It supports the standard configuration settings as used in the
Elastic Stack such as "ssl.verification_mode" and
"ssl.certificate_authorities" as well as all file formats used
in other parts of Elasticsearch security (such as PEM, JKS,
PKCS#12, PKCS#8, et al).
Adds a set of geo classes to represent geo data in the JDBC driver and
to be used as an intermediate format to pass geo shapes for indexing
and query generation in #35320.
Relates to #35767 and #35320
Currently we read and write 64KB at a time in the nio libraries. As a
single byte buffer per event loop thread does not consume much memory,
there is little reason to not increase it further. This commit increases
the buffer to 256KB but still limits a single write to 64KB. The write
limit could be increased, but too high of a write limit will lead to
copying more data (if all the data is not flushed and needs to be copied
on the next call). This is something to explore in the future.
Closing a channel using TLS/SSL requires reading and writing a
CLOSE_NOTIFY message (for pre-1.3 TLS versions). Many implementations do
not actually send the CLOSE_NOTIFY message, which means we are depending
on the TCP close from the other side to ensure channels are closed. In
case there is an issue with this, we need a timeout. This commit adds a
timeout to the channel close process for TLS secured channels.
As part of this change, we need a timer service. We could use the
generic Elasticsearch timeout threadpool. However, it would be nice to
have a local to the nio event loop timer service dedicated to network needs. In
the future this service could support read timeouts, connect timeouts,
request timeouts, etc. This commit adds a basic priority queue backed
service. Since our timeout volume (channel closes) is very low, this
should be fine. However, this can be updated to something more efficient
in the future if needed (timer wheel). Everything being local to the event loop
thread makes the logic simple as no locking or synchronization is necessary.
`PageCacheRecycler` is the class that creates and holds pages of arrays
for various uses. `BigArrays` is just one user of these pages. This
commit moves the constants that define the page sizes for the recycler
to be on the recycler class.
This is related to #27260. In Elasticsearch all of the messages that we
serialize to write to the network are composed of heap bytes. When you
read or write to a nio socket in java, the heap memory you passed down
must be copied to/from direct memory. The JVM internally does some
buffering of the direct memory, however it is essentially unbounded.
This commit introduces a simple mechanism of buffering and copying the
memory in transport-nio. Each network event loop is given a 64kb
DirectByteBuffer. When we go to read we use this buffer and copy the
data after the read. Additionally, when we go to write, we copy the data
to the direct memory before calling write. 64KB is chosen as this is the
default receive buffer size we use for transport-netty4
(NETTY_RECEIVE_PREDICTOR_SIZE).
Since we only have one buffer per thread, we could afford larger.
However, if we the buffer is large and not all of the data is flushed in
a write call, we will do excess copies. This is something we can
explore in the future.
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
This commit is related to #32517. It allows an "sni_server_name"
attribute on a DiscoveryNode to be propagated to the server using
the TLS SNI extentsion. Prior to this commit, this functionality
was only support for the netty transport. This commit adds this
functionality to the security nio transport.
Adds an XContent sub parser class that can to wrap another
XContent parser at the beginning of an object and allow skiping
all children in case of the parsing failure. It also uses this
subparser to ignore the rest of the GeoJson shape if the
parsing fails and we need to ignore the geoshape due to the
ignore_malformed flag.
Supersedes #34498Closes#34047
This change adds a `frozen` engine that allows lazily open a directory reader
on a read-only shard. The engine wraps general purpose searchers in a LazyDirectoryReader
that also allows to release and reset the underlying index readers after any and before
secondary search phases.
Relates to #34352
Adds checks for misbehaving parsers. The checks aren't perfect at all but
they are simple and fast enough that we can do them all the time so
they'll catch most badly behaving parsers.
Closes#34351
The testCharsBeginsWith test has a check that a random prefix of length
2 is not the prefix of a char[]. However, there is no check that the
char[] is not randomly generated with the same two characters as the
prefix. This change ensures that the char[] does not begin with the
prefix.
Closes#34765
With this commit we cleanup hand-coded duplicate checks in XContent
parsing. They were necessary previously but since we reconfigured the
underlying parser in #22073 and #22225, these checks are obsolete and
were also ineffective unless an undocumented system property has been
set. As we also remove this escape hatch, we can remove the additional
checks as well.
Closes#22253
Relates #34588
Although we allow to index BigInteger and BigDecimal into a keyword
field, source filtering on these fields would fail
as XContentBuilder was not able to deserialize BigInteger and BigDecimal
to json.
This modifies XContentBuilder to allow to handle BigInteger and
BigDecimal.
Closes#32395
This change cleans up "unused variable" warnings. There are several cases were we
most likely want to suppress the warnings (especially in the client documentation test
where the snippets contain many unused variables). In a lot of cases the unused
variables can just be deleted though.
This change adds a `_source` only snapshot repository that allows to wrap
any existing repository as a _backend_ to snapshot only the `_source` part
including live docs markers. Snapshots taken with the `source` repository
won't include any indices, doc-values or points. The snapshot will be reduced in size and
functionality such that it requires full re-indexing after it's successfully restored.
The restore process will copy the `_source` data locally starts a special shard and engine
to allow `match_all` scrolls and searches. Any other query, or get call will fail with and unsupported operation exception. The restored index is also marked as read-only.
This feature aims mainly for disaster recovery use-cases where snapshot size is
a concern or where time to restore is less of an issue.
**NOTE**: The snapshot produced by this repository is still a valid lucene index. This change doesn't allow for any longer retention policies which is out of scope for this change.
This change cleans up some methods in the CharArrays class from x-pack, which
includes the unification of char[] to utf8 and utf8 to char[] conversions that
intentionally do not use strings. There was previously an implementation in
x-pack and in the reloading of secure settings. The method from the reloading
of secure settings was adopted as it handled more scenarios related to the
backing byte and char buffers that were used to perform the conversions. The
cleaned up class is moved into libs/core to allow it to be used by requests
that will be migrated to the high level rest client.
Relates #32332
The dissect library will be used for the ingest node as an alternative
to Grok to split a string based on a pattern. Dissect differs from
Grok such that regular expressions are not used to split the string.
Note - Regular expressions are used during construction of the
objects, but not in the hot path.
A dissect pattern takes the form of: '%{a} %{b},%{c}' which is
composed of 3 keys (a,b,c) and two delimiters (space and comma).
This dissect pattern will match a string of the form: 'foo bar,baz'
and will result a key/value pairing of 'a=foo, b=bar, and c=baz'.
See the comments in DissectParser for a full explanation.
This commit does not include the ingest node processor that will consume
it. However, the consumption should be a trivial mapping between the
key/value pairing returned by the parser and the key/value pairing
needed for the IngestDocument.
Today content type detection on an input stream works by peeking up to
twenty bytes into the stream. If the stream is headed by more whitespace
than twenty bytes, we might fail to detect the content type. We should
be ignoring this whitespace before attempting to detect the content
type. This commit does that by ignoring all leading whitespace in an
input stream before attempting to guess the content type.
* INGEST: Fix ThreadWatchDog Throwing on Shutdown
* #32539 is caused by the fact that ThreadWatchDog.Default could throw on shutdown if the ThreadPool is interrupted while `interruptLongRunningExecutions` is in progress. This is a result of the watchdog not having a lifecycle of its own (normally it terminates when the threadpool terminates).
* We can't easily use `org.elasticsearch.common.util.concurrent.EsRejectedExecutionException#isExecutorShutdown` to catch this state the same way other components do since thatwould require adding the core lib to Grok as a dependency
* Since we have no knowledge of the lifecycle in this compontent since we're only passed the scheduler `BiFunction` I fixed this by only scheduling the watchdog when there's actually registered threads in it.
* I think using the patter of locking via two `Atomic*` values should not be much of a performance concern here under load since either the integer will likely be > 0 in this case (because we have multiple Grok in parallel) or the running state will be true because there likely was at least one thread registered when the watchdog ran and so the enqueing of the watchdog task during `register` will happen very rarely here (in the worst case scenario of only a single Grok thread it will happen less frequently than once every `ingest.grok.watchdog.interval`). The atomic update on the count should not be relevant relative to the cost of adding a new node to the CHM either.
* Fixes#32539
* Also fixes the watchdog to run if it doens't have to in general.
* Detect and prevent configuration that triggers a Gradle bug
As we found in #31862, this can lead to a lot of wasted time as it's not
immediatly obvius what's going on.
Givent how many projects we have it's getting increasingly easier to run
into gradle/gradle#847.
This is related to #27260. It adds the SecurityNioTransport to the
security plugin. Additionally, it adds support for ip filtering. And it
randomly uses the nio transport in security integration tests.
This change adds Expected Reciprocal Rank (ERR) as a ranking evaluation metric
as descriped in:
Chapelle, O., Metlzer, D., Zhang, Y., & Grinspan, P. (2009).
Expected reciprocal rank for graded relevance.
Proceeding of the 18th ACM Conference on Information and Knowledge Management.
https://doi.org/10.1145/1645953.1646033
ERR is an extension of the classical reciprocal rank to the graded relevance
case and assumes a cascade browsing model. It quantifies the usefulness of a
document at rank `i` conditioned on the degree of relevance of the items at ranks
less than `i`. ERR seems to be gain traction as an alternative to (n)DCG, so it
seems like a good metric to support. Also ERR seems to be the default optimization
metric used for training in RankLib, a widely used learning to rank library.
Relates to #29653
This is the first x-pack API we're adding to the high level REST client
so there is a lot to talk about here!
= Open source
The *client* for these APIs is open source. We're taking the previously
Elastic licensed files used for the `Request` and `Response` objects and
relicensing them under the Apache 2 license.
The implementation of these features is staying under the Elastic
license. This lines up with how the rest of the Elasticsearch language
clients work.
= Location of the new files
We're moving all of the `Request` and `Response` objects that we're
relicensing to the `x-pack/protocol` directory. We're adding a copy of
the Apache 2 license to the root fo the `x-pack/protocol` directory to
line up with the language in the root `LICENSE.txt` file. All files in
this directory will have the Apache 2 license header as well. We don't
want there to be any confusion. Even though the files are under the
`x-pack` directory, they are Apache 2 licensed.
We chose this particular directory layout because it keeps the X-Pack
stuff together and easier to think about.
= Location of the API in the REST client
We've been following the layout of the rest-api-spec files for other
APIs and we plan to do this for the X-Pack APIs with one exception:
we're dropping the `xpack` from the name of most of the APIs. So
`xpack.graph.explore` will become `graph().explore()` and
`xpack.license.get` will become `license().get()`.
`xpack.info` and `xpack.usage` are special here though because they
don't belong to any proper category. For now I'm just calling
`xpack.info` `xPackInfo()` and intend to call usage `xPackUsage` though
I'm not convinced that this is the final name for them. But it does get
us started.
= Jars, jars everywhere!
This change makes the `xpack:protocol` project a `compile` scoped
dependency of the `x-pack:plugin:core` and `client:rest-high-level`
projects. I intend to keep it a compile scoped dependency of
`x-pack:plugin:core` but I intend to bundle the contents of the protocol
jar into the `client:rest-high-level` jar in a follow up. This change
has grown large enough at this point.
In that followup I'll address javadoc issues as well.
= Breaking-Java
This breaks that transport client by a few classes around. We've
traditionally been ok with doing this to the transport client.
Currently we set local addresses on the creation time of a NioChannel.
However, this may return null as the local address may not have been
set yet. An example is the local address has not been set on a client
channel as the connection process is not yet complete.
This PR modifies the getter to set the local field if it is currently null.
Currently, when we open a new channel, we pass it an
InboundChannelBuffer. The channel buffer is preallocated a single 16kb
page. However, there is no guarantee that this channel will be read from
anytime soon. Instead, this commit does not preallocate that page. That
page will be allocated when we receive a read event.
This is related to #28898. This PR implements pooling of bytes arrays
when reading from the wire in the http server transport. In order to do
this, we must integrate with netty reference counting. That manner in
which this PR implements this is making Pages in InboundChannelBuffer
reference counted. When we accessing the underlying page to pass to
netty, we retain the page. When netty releases its bytebuf, it releases
the underlying pages we have passed to it.
This is related to #27260. Currently when we queue a write with a
channel we set OP_WRITE and wait until the next selection loop to flush
the write. However, if the channel does not have a pending write, it
is probably ready to flush. This PR implements an optimistic flush logic
that will attempt this flush.
This adds a thread interrupter that allows us to encapsulate calls to org.joni.Matcher#search()
This method can hang forever if the regex expression is too complex.
The thread interrupter in the background checks every 3 seconds whether there are threads
execution the org.joni.Matcher#search() method for longer than 5 seconds and
if so interrupts these threads.
Joni has checks that that for every 30k iterations it checks if the current thread is interrupted and
if so returns org.joni.Matcher#INTERRUPTED
Closes#28731
This is related to #28898. This commit adds the acceptor thread name to
the method checking if this thread is a transport thread. Additionally,
it modifies the nio http transport to use the same worker name as the
netty4 http server transport.
This is related to #27260. This commit combines the AcceptingSelector
and SocketSelector classes into a single NioSelector. This change
allows the same selector to handle both server and socket channels. This
is valuable as we do not necessarily want a dedicated thread running for
accepting channels.
With this change, this commit removes the configuration for dedicated
accepting selectors for the normal transport class. The accepting
workload for new node connections is likely low, meaning that there is
no need to dedicate a thread to this process.
ObjectParser should throw XContentParseExceptions, not IAE. A dedicated parsing
exception can includes the place where the error occurred.
Closes#30605
Currently nio and netty modules use the CompletableFuture class for
managing listeners. This is unfortunate as that class accepts
Throwable. This commit adds a class CompletableContext that wraps
the CompletableFuture but does not accept Throwable. This allows the
modification of netty and nio logic to no longer handle Throwable.
This is related to #27260. The elasticsearch-nio jar is supposed to be
a library opposed to a framework. Currently it internally logs certain
exceptions. This commit modifies it to not rely on logging. Instead
exception handlers are passed by the applications that use the jar.
This commit is related to #28898. It adds an nio driven http server
transport. Currently it only supports basic http features. Cors,
pipeling, and read timeouts will need to be added in future PRs.
`javadoc` will switch from detaulting to html4 to html5 in "a future
release". We should get ahead of it so we're not surprised. Also, HTML5
is the future! Er, the present. Anyway, this follows up from #30220 to
make the Javadoc for two of the four remaining projects HTML5
compatible.
Currently this fails because the Eclipse configuration splits the main and test
folders into separate projects to avoid circular dependencies.
Relates #29336
Fails the build if any subprojects of `:libs` have dependencies in `:libs`
except for `:libs:elasticsearch-core`.
Since we now have three places where we resolve project substitutions
I've added `dependencyToProject` to `project.ext` in all projects. It
resolves both `project` style dependencies and "external" style (like
"org.elasticsearch:elasticsearch-core:${version}") dependencies to
`Project`s using the `projectSubstitutions`. I use this new function all
three places where resovle project substitutions.
Finally this pulls `apply plugin: 'elasticsearch.build'` out of
`libs/*/build.gradle` and into a subprojects clause in
`libs/build.gradle`. I do this entirely so that I can call
`tasks.precommit.dependsOn checkDependencies` without waiting for the
subprojects to be evaluated or worrying about whether or not they have
`precommit` set up in a normal way.
This commit moves the `TimeValue` class into the elasticsearch-core project.
This allows us to use this class in many of our other projects without relying
on the entire `server` jar.
Relates to #28504
* Move Streams.copy into elasticsearch-core and make a multi-release jar
This moves the method `Streams.copy(InputStream in, OutputStream out)` into the
`elasticsearch-core` project (inside the `o.e.core.internal.io` package). It
also makes this class into a multi-release class where the Java 9 equivalent
uses `InputStream#transferTo`.
This is a followup from
https://github.com/elastic/elasticsearch/pull/29300#discussion_r178147495
* Move ObjectParser into the x-content lib
This moves `ObjectParser`, `AbstractObjectParser`, and
`ConstructingObjectParser` into the libs/x-content dependency. This decoupling
allows them to be used for parsing for projects that don't want to depend on the
entire Elasticsearch jar.
Relates to #28504
* Move Tuple into elasticsearch-core
This allows us to use Tuple from other projects that don't want to rely on the
entire Elasticsearch jar.
I have also added very simple tests, since there were none.
Relates tangentially to #28504
This moves the `Nullable` annotation into the elasticsearch-core project, so it
may be used without relying entirely on the server jar. This will allow us to
decouple more pieces to make them smaller.
In addition, there were two different `Nullable` annotations, these have all
been moved to the ES version rather than the inject version.
* Begin moving XContent to a separate lib/artifact
This commit moves a large portion of the XContent code from the `server` project
to the `libs/xcontent` project. For the pieces that have been moved, some
helpers have been duplicated to allow them to be decoupled from ES helper
classes. In addition, `Booleans` and `CheckedFunction` have been moved to the
`elasticsearch-core` project.
This decoupling is a move so that we can eventually make things like the
high-level REST client not rely on the entire ES jar, only the parts it needs.
There are some pieces that are still not decoupled, in particular some of the
XContent tests still remain in the server project, this is because they test a
large portion of the pluggable xcontent pieces through
`XContentElasticsearchException`. They may be decoupled in future work.
Additionally, there may be more piecese that we want to move to the xcontent lib
in the future that are not part of this PR, this is a starting point.
Relates to #28504
When we copied IOUtils into the Elasticsearch codebase from Lucene, we
brought with it its handling of throwables which are out of whack with
how we handle throwables in our codebase. This commit modifies our copy
of IOUtils to be consistent with how we handle throwables today: do not
catch them. We take advantage of this cleanup to simplify IOUtils.
Eclipse Oxygen doesn't seem to be able to infer the correct type
arguments for Arrays::asList in the given test context. Adding cast to
make this more explicit.
As we have factored Elasticsearch into smaller libraries, we have ended
up in a situation that some of the dependencies of Elasticsearch are not
available to code that depends on these smaller libraries but not server
Elasticsearch. This is a good thing, this was one of the goals of
separating Elasticsearch into smaller libraries, to shed some of the
dependencies from other components of the system. However, this now
means that simple utility methods from Lucene that we rely on are no
longer available everywhere. This commit copies IOUtils (with some small
formatting changes for our codebase) into the fold so that other
components of the system can rely on these methods where they no longer
depend on Lucene.
This commit is related to #27260. Currently there is a weird
relationship between channel contexts and nio channels. The selectors
use the context for read and writing. But the selector operates directly
on the nio channel for registering, closing, and connecting.
This commit works on improving this relationship. The selector operates
directly on the context which wraps the low level java.nio.channels. The
NioChannel class is simply an API that is used to interact with the
channel (sending messages from outside the selector event loop,
scheduling a close, adding listeners, etc). The context is only used
internally by the channel to implement these apis and by the selector to
perform these operations.
* Remove log4j dependency from elasticsearch-core
This removes the log4j dependency from our elasticsearch-core project. It was
originally necessary only for our jar classpath checking. It is now replaced by
a `Consumer<String>` so that the es-core dependency doesn't have external
dependencies.
The parts of #28191 which were moved in conjunction (like `ESLoggerFactory` and
`Loggers`) have been moved back where appropriate, since they are not required
in the core jar.
This is tangentially related to #28504
* Add javadocs for `output` parameter
* Change @code to @link
This is a fix for #28729. Currently if a write operation is not properly
queued with a selector we notify the listener. However, we are doing
this by calling a method that is only meant for the selector thread to
call. This commit fixes that issue.
This commit is related to #27260. Currently have a channel context that
implements reading and writing logic for socket channels. Additionally,
we have exception contexts to handle exceptions. And accepting contexts
to handle accepted channels. This PR introduces a ChannelContext that
handles close and exception handling for all channel types.
Additionally, it has implementers that provide specific functionality
for socket channels (read and writing). And specific functionality for
server channels (accepting).
This commit lessens the burden on configuring settings.gradle when new
projects are added. In particular, this makes it trivial to move a
plugin to a module (or vice versa).
This commit is related to #27260. Right now we have separate read and
write contexts for implementing specific protocol logic. However, some
protocols require a closer relationship between read and write
operations than is allowed by our current model. An example is HTTP
which might require a write if some problem with request parsing was
encountered.
Additionally, some protocols require close messages to be sent when a
channel is shutdown. This is also problematic in our current model,
where we assume that channels should simply be queued for close and
forgotten.
This commit transitions to a single ChannelContext which implements
all read, write, and close logic for protocols. It is the job of the
context to tell the selector when to close the channel. A channel can
still be manually queued for close with a selector. This is how server
channels are closed for now. And this route allows timeout mechanisms on
normal channel closes to be implemented.
This is related to #27933. It introduces a jar named elasticsearch-core
in the lib directory. This commit moves the JarHell class from server to
elasticsearch-core. Additionally, PathUtils and some of Loggers are
moved as JarHell depends on them.
This is related to #27260. This commit moves the NioTransport from
:test:framework to a new nio-transport plugin. Additionally, supporting
tcp decoding classes are moved to this plugin. Generic byte reading and
writing contexts are moved to the nio library.
Additionally, this commit adds a basic MockNioTransport to
:test:framework that is a TcpTransport implementation for testing that
is driven by nio.
This commit adds the infrastructure to plugin building and loading to
allow one plugin to extend another. That is, one plugin may extend
another by the "parent" plugin allowing itself to be extended through
java SPI. When all plugins extending a plugin are finished loading, the
"parent" plugin has a callback (through the ExtensiblePlugin interface)
allowing it to reload SPI.
This commit also adds an example plugin which uses as-yet implemented
extensibility (adding to the painless whitelist).
* Splits nio project into two for eclipse build only
https://github.com/elastic/elasticsearch/pull/27801 introduced a new gradle project `:libs:elasticsearch-nio` which creates cyclical project dependencies when importingthe projects into Eclipse.
This change applies the same trick as we have for the core project where, and building for Eclipse, splits the `:libs:elasticsearch-nio` project into `:libs:elasticsearch-nio` which points to `src/main` and `:libs:elasticsearch-nio-tests` which points to `src/test`. This prevents cyclical project dependencies in Eclipse arising from the fact that eclipse does not separate compile/runtime dependencies from test dependencies.
* Removes integTest bits since there are none
This is related to #27802. This commit adds a jar called
elasticsearch-nio that contains the base nio classes that will be used
for the tcp nio transport and eventually the http nio transport.
The jar does not depend on elasticsearch:core, so all references to core
have been removed.