This commit overhauls the documentation of discovery and cluster coordination,
removing mention of the Zen Discovery module and replacing it with docs for the
new cluster coordination mechanism introduced in 7.0.
Relates #32006
This is related to #36652. In 7.0 we plan to deprecate a number of
settings that make reference to the concept of a tcp transport. We
mostly just have a single transport type now (based on tcp). Settings
should only reference tcp if they are referring to socket options. This
commit updates the settings in the docs. And removes string usages of
the old settings. Additionally it adds a missing remote compress setting
to the docs.
When a security manager is present, the JVM will cache positive hostname
lookups indefinitely. This can be problematic, especially in the modern
world with cloud services where DNS addresses can change, or
environments using Docker containers where IP addresses could be
considered ephemeral. This behavior impacts cluster discovery,
cross-cluster replication and cross-cluster search, reindex from remote,
snapshot repositories, webhooks in Watcher, external authentication
mechanisms, and the Elastic Stack Monitoring Service. The experience of
watching a DNS lookup change yet not be reflected within Elasticsearch
is a poor experience for users. The reason the JVM has this is guard
against DNS cache posioning attacks. Yet, there is already a defense in
the modern world against such attacks: TLS. With proper certificate
validation, even if a resolver falls prey to a DNS cache poisoning
attack, using TLS would neuter the attack. Therefore we have a policy
with dubious security value that significantly impacts usability. As
such we make the usability/security tradeoff towards usability, since
the security risks are very low. This commit introduces new system
properties that Elasticsearch observes to override the JVM DNS cache
policy.
In real deployments it is important that clusters are properly configured to
avoid accidentally forming multiple independent clusters at cluster
bootstrapping time. However we also expect to be able to unpack Elasticsearch
and start up one or more nodes without any up-front configuration, and have
them do their best to find each other and form a cluster after a few seconds.
This change adds a delayed automatic bootstrapping process to nodes that start
up with no relevant settings set to support the desired out-of-the-box
experience without compromising safety in properly-configured deployments.
Recent Docker for Mac releases[1] have a different path to the tty for
accessing the console of the xhyve vm, required for altering the
`vm.max_map_count` sysctl.
Update instructions on how to enter the xhyve vm for altering the
`vm.max_map_count` sysctl setting on Docker for Mac.
Closes#34817
[1]
https://forums.docker.com/t/is-it-possible-to-ssh-to-the-xhyve-machine/17426/13
If the underlying mount point for the JNA temporary directory is mounted
noexec on Linux, then the JVM will not be able to map the native code in
as executable. This will prevent JNA from executing and will prevent
Elasticsearch from being able to execute some functions that rely on
native code (e.g., memory locking, and installing system call
filters). We do not want to get into the business of catching exceptions
and parsing messages towards this because these exception messages can
change on us. We also do not want to jump through a lot of hoops to
check the underlying mount point for noexec. Instead, we will rely on
documentation to address this problem. This commit adds to the important
system configuration section of the docs that the JNA temporary
directory is not on a mount point with the noexec mount option.
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`.
Changes the default of the `node.name` setting to the hostname of the
machine on which Elasticsearch is running. Previously it was the first 8
characters of the node id. This had the advantage of producing a unique
name even when the node name isn't configured but the disadvantage of
being unrecognizable and not being available until fairly late in the
startup process. Of particular interest is that it isn't available until
after logging is configured. This forces us to use a volatile read
whenever we add the node name to the log.
Using the hostname is available immediately on startup and is generally
recognizable but has the disadvantage of not being unique when run on
machines that don't set their hostname or when multiple elasticsearch
processes are run on the same host. I believe that, taken together, it
is better to default to the hostname.
1. Running multiple copies of Elasticsearch on the same node is a fairly
advanced feature. We do it all the as part of the elasticsearch build
for testing but we make sure to set the node name then.
2. That the node.name defaults to some flavor of "localhost" on an
unconfigured box feels like it isn't going to come up too much in
production. I expect most production deployments to at least set the
hostname.
As a bonus, production deployments need no longer set the node name in
most cases. At least in my experience most folks set it to the hostname
anyway.
The main installation instructions page for the Windows MSI installer includes a header at the top to indicate that the installer is in beta, but the Installing Elasticsearch page does not. This commit adds the beta label to the MSI entry within the installation options.
The maximum map count boostrap check can be a hindrance to users that do
not own the underlying platform on which they are executing
Elasticsearch. This is because addressing it requires tuning the kernel
and a platform provider might now allow this, especially on shared
infrastructure. However, this bootstrap check is not needed if mmapfs is
not in use. Today we do not have a way for the user to communicate that
they are not going to use mmapfs. This commit therefore adds a setting
that enables the user to disallow mmapfs. When mmapfs is disallowed, the
maximum map count bootstrap check is not enforced. Additionally, we
fallback to a different default index store and prevent the explicit use
of mmapfs for an index.
The docs here incorrectly state that it is okay for a heap dump file to
exist when heap dump path is configured to a fixed filename. This is
incorrect, the JVM will fail to write the heap dump if a heap dump file
already exists at the specified location (see the DumpWriter constructor
DumpWriter::DumpWriter(const char* path) in the JVM source).
On some Linux distributions tmpfiles.d cleans files and
directories under /tmp if they haven't been accessed for
10 days.
This can cause problems for ML as ML is currently the only
component that uses the temp directory more than a few
seconds after startup. If you didn't open an ML job for
10 days and then tried to open one then the temp directory
would have been deleted.
This commit prevents the problem occurring in the case of
Elasticsearch being managed by systemd, as systemd private
temp directories are not subject to periodic cleanup (by
default).
Additionally there are now some docs to warn people about
the risk and suggest a manual mitigation for .tar.gz users.
First, some background: we have 15 different methods to get a logger in
Elasticsearch but they can be broken down into three broad categories
based on what information is provided when building the logger.
Just a class like:
```
private static final Logger logger = ESLoggerFactory.getLogger(ActionModule.class);
```
or:
```
protected final Logger logger = Loggers.getLogger(getClass());
```
The class and settings:
```
this.logger = Loggers.getLogger(getClass(), settings);
```
Or more information like:
```
Loggers.getLogger("index.store.deletes", settings, shardId)
```
The goal of the "class and settings" variant is to attach the node name
to the logger. Because we don't always have the settings available, we
often use the "just a class" variant and get loggers without node names
attached. There isn't any real consistency here. Some loggers get the
node name because it is convenient and some do not.
This change makes the node name available to all loggers all the time.
Almost. There are some caveats are testing that I'll get to. But in
*production* code the node name is node available to all loggers. This
means we can stop using the "class and settings" variants to fetch
loggers which was the real goal here, but a pleasant side effect is that
the ndoe name is now consitent on every log line and optional by editing
the logging pattern. This is all powered by setting the node name
statically on a logging formatter very early in initialization.
Now to tests: tests can't set the node name statically because
subclasses of `ESIntegTestCase` run many nodes in the same jvm, even in
the same class loader. Also, lots of tests don't run with a real node so
they don't *have* a node name at all. To support multiple nodes in the
same JVM tests suss out the node name from the thread name which works
surprisingly well and easy to test in a nice way. For those threads
that are not part of an `ESIntegTestCase` node we stick whatever useful
information we can get form the thread name in the place of the node
name. This allows us to keep the logger format consistent.
We removed the default_fs store type yet the docs still contain a
reference to them. This commit addresses that by removing this
reference, and changing a reference to this section of the docs to
instead refer to mmapfs.
In the section of the bootstrap checks docs for the maximum map count
check, we refer to max size virtual memory check and explicitly call out
the maximum size virtual memory check as being the previous
point. However, this is not correct as the previous point is currently
the max file size check. It does make sense for these two checks to be
proximate to each other in the docs so this commit reorders the checks
so that the maximum size virtual memory check indeed comes before the
maximum map count check. This makes the sense in the maximum map count
check correct.
This commit removes the link to an oss-MSI; there is only one version of the MSI, which includes X-Pack.
(cherry picked from commit d2e5db8a806ec8a25162f79db5209aceed4f30f7)
This switches the docs tests from the `oss-zip` distribution to the
`zip` distribution so they have xpack installed and configured with the
default basic license. The goal is to be able to merge the
`x-pack/docs` directory into the `docs` directory, marking the x-pack
docs with some kind of marker. This is the first step in that process.
This also enables `-Dtests.distribution` support for the `docs`
directory so you can run the tests against the `oss-zip` distribution
with something like
```
./gradlew -p docs check -Dtests.distribution=oss-zip
```
We can set up Jenkins to run both.
Relates to #30665
This commit adds the distribution type to the startup scripts so that we
can discern from log output and the main response the type of the
distribution (deb/rpm/tar/zip).
This commit adds the distribution flavor (default versus oss) to the
build process which is passed through the startup scripts to
Elasticsearch. This change will be used to customize the message on
attempting to install/remove x-pack based on the distribution flavor.