Java 8 presents the JVM options slightly differently when displaying via
-XX:+PrintFlagsFinal. This commit adapts the JVM options parser for this
possibility.
Relates #42009
This commit removes manual parsing of JVM options when calculating
ergonomics. This is to avoid a situation that we parse values
differently than the JVM would. In fact, we already have a bug along
these lines today. It is possible to start the JVM with the same flag
multiple times on the command line. In this case, the last value
wins. For example, -Xmx1g -Xmx2g would start the JVM with a heap size of
two gigabytes. Our JVM ergonomics ignores this possibility and instead
the first value is winning!
Our strategy to avoid manual parsing of the JVM options is to start the
Java command line parser (without actually starting a JVM) by invoking
java with the same command line flags as presented and request that the
JVM tell us what values it would start with. This ensures that we have
the correct values when making ergonomic decisions.
Moreover, our strategy also is ignoring ES_JAVA_OPTS which could
override the heap size as well leading to incorrect ergonomic
choices. This commit address this issue too.
hamcrest has some improvements in newer versions, like FileMatchers
that make assertions regarding file exists cleaner. This commit upgrades
to the latest version of hamcrest so we can start using new and improved
matchers.
* 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
In the long run we want to move all of startup to a Java program. This
will simplify our startup scripts and make maintenance of startup less
dependent on the underlying platform that we run on. This commit moves
the creation of the temporary directory off of system-dependent commands
and onto a simple Java program.
With this commit we add the possibility to define further JVM options (and
system properties) based on the current environment. As a proof of concept, it
chooses Netty's allocator ergonomically based on the maximum defined heap size.
We switch to the unpooled allocator at 1GB heap size (value determined
experimentally, see #30684 for more details). We are also explicit about the
choice of the allocator in either case.
Relates #30684
The java version checker requires being written with java 7 APIs.
In order to use java 8 apis in other launcher utilities, this commit
moves the java version checker back to its own jar.
We no longer need animal sniffer because we use JDK functionality
(introduced in JDK 9) to target older versions of the JDK for
compilation. This functionality means that the JDK handles the problem
of ensuring that we do not use JDK APIs from the version that we are
compiling from that are not available in the version that we are
compiling to. A previous commit removed this for the REST client (where
we target JDK 7) but a few traces were left behind.
This commit reorganizes some of the content in the configuring
Elasticsearch section of the docs. The changes are:
- move JVM options out of system configuration into configuring
Elasticsearch
- move JVM options to its own page of the docs
- move configuring the heap to important Elasticsearch settings
- move configuring the heap to its own page of the docs
- move all important settings to individual pages in the docs
- remove bootstrap.memory_lock from important settings, this is covered
in the swap section of system configuration
Relates #27755
JDK 9 has removed JVM options that were valid in JDK 8 (e.g., GC logging
flags) and replaced them with new flags that are not available in JDK
8. This means that a single JVM options file can no longer apply to JDK
8 and JDK 9, complicating development, complicating our packaging story,
and complicating operations. This commit extends the JVM options syntax
to specify the range of versions the option applies to. If the running
JVM matches the range of versions, the flag will be used to start the
JVM otherwise the flag will be ignored.
We implement this parser in Java for simplicity, and with this we start
our first step towards a Java launcher.
Relates #27675
Jason Tedor
Ryan Ernst
Alpar Torok
Kazuhiro Sera
Daniel Mitterdorfer