In order to support JSON log format, a custom pattern layout was used and its configuration is enclosed in ESJsonLayout. Users are free to use their own patterns, but if smooth Beats integration is needed, they should use ESJsonLayout. EvilLoggerTests are left intact to make sure user's custom log patterns work fine.
To populate additional fields node.id and cluster.uuid which are not available at start time,
a cluster state update will have to be received and the values passed to log4j pattern converter.
A ClusterStateObserver.Listener is used to receive only one ClusteStateUpdate. Once update is received the nodeId and clusterUUid are set in a static field in a NodeAndClusterIdConverter.
Following fields are expected in JSON log lines: type, tiemstamp, level, component, cluster.name, node.name, node.id, cluster.uuid, message, stacktrace
see ESJsonLayout.java for more details and field descriptions
Docker log4j2 configuration is now almost the same as the one use for ES binary.
The only difference is that docker is using console appenders, whereas ES is using file appenders.
relates: #32850
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.
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.
587409e893 introduced a bug where an example of the format of a request which contained placeholder values was attempted to be tested. This change adds `NOTCONSOLE` to that snippet as the immediately following snippet tests a concrete example.
220212dd69 introduced a bug because the test substitution was looking for `otherhost` where the snippet contained `oldhost`. This change fixes the substitution
Przemyslaw Gomulka
Nik Everett
Colin Goodheart-Smithe
Jason Tedor
Clinton Gormley