Introduce system JVM options (#48252)

This commit moves JVM options that we are setting on behalf of the user
that we do not expect them to fiddle with out of the jvm.options
configuration file and into the JVM options parser. In this way, we
discourage fiddling with these settings, but more importantly, we ensure
that as we evolve or add to these settings that a user would pick these
pick instead of being left behind if they have a modified jvm.options
file and do not pick any new that come with the distribution.

distribution/src/config/jvm.options

@@ -46,47 +46,7 @@
 # 10-:-XX:G1ReservePercent=25
 # 10-:-XX:InitiatingHeapOccupancyPercent=30
 
-## DNS cache policy
+## JVM temporary directory
-# cache ttl in seconds for positive DNS lookups noting that this overrides the
-# JDK security property networkaddress.cache.ttl; set to -1 to cache forever
--Des.networkaddress.cache.ttl=60
-# cache ttl in seconds for negative DNS lookups noting that this overrides the
-# JDK security property networkaddress.cache.negative ttl; set to -1 to cache
-# forever
--Des.networkaddress.cache.negative.ttl=10
-
-## optimizations
-
-# pre-touch memory pages used by the JVM during initialization
--XX:+AlwaysPreTouch
-
-## basic
-
-# explicitly set the stack size
--Xss1m
-
-# set to headless, just in case
--Djava.awt.headless=true
-
-# ensure UTF-8 encoding by default (e.g. filenames)
--Dfile.encoding=UTF-8
-
-# use our provided JNA always versus the system one
--Djna.nosys=true
-
-# turn off a JDK optimization that throws away stack traces for common
-# exceptions because stack traces are important for debugging
--XX:-OmitStackTraceInFastThrow
-
-# flags to configure Netty
--Dio.netty.noUnsafe=true
--Dio.netty.noKeySetOptimization=true
--Dio.netty.recycler.maxCapacityPerThread=0
-
-# log4j 2
--Dlog4j.shutdownHookEnabled=false
--Dlog4j2.disable.jmx=true
-
 -Djava.io.tmpdir=${ES_TMPDIR}
 
 ## heap dumps
@@ -103,7 +63,6 @@ ${heap.dump.path}
 ${error.file}
 
 ## JDK 8 GC logging
-
 8:-XX:+PrintGCDetails
 8:-XX:+PrintGCDateStamps
 8:-XX:+PrintTenuringDistribution
@@ -115,6 +74,3 @@ ${error.file}
 
 # JDK 9+ GC logging
 9-:-Xlog:gc*,gc+age=trace,safepoint:file=${loggc}:utctime,pid,tags:filecount=32,filesize=64m
-# due to internationalization enhancements in JDK 9 Elasticsearch need to set the provider to COMPAT otherwise
-# time/date parsing will break in an incompatible way for some date patterns and locals
-9-:-Djava.locale.providers=COMPAT

distribution/tools/launchers/src/main/java/org/elasticsearch/tools/launchers/JvmOptionsParser.java

@@ -90,8 +90,13 @@ final class JvmOptionsParser {
             final List<String> substitutedJvmOptions =
                 substitutePlaceholders(jvmOptions, Collections.singletonMap("ES_TMPDIR", System.getenv("ES_TMPDIR")));
             final List<String> ergonomicJvmOptions = JvmErgonomics.choose(substitutedJvmOptions);
-            substitutedJvmOptions.addAll(ergonomicJvmOptions);
+            final List<String> systemJvmOptions = SystemJvmOptions.systemJvmOptions();
-            final String spaceDelimitedJvmOptions = spaceDelimitJvmOptions(substitutedJvmOptions);
+            final List<String> finalJvmOptions =
+                new ArrayList<>(systemJvmOptions.size() + substitutedJvmOptions.size() + ergonomicJvmOptions.size());
+            finalJvmOptions.addAll(systemJvmOptions); // add the system JVM options first so that they can be overridden
+            finalJvmOptions.addAll(substitutedJvmOptions);
+            finalJvmOptions.addAll(ergonomicJvmOptions);
+            final String spaceDelimitedJvmOptions = spaceDelimitJvmOptions(finalJvmOptions);
             Launchers.outPrintln(spaceDelimitedJvmOptions);
             Launchers.exit(0);
         } else {

distribution/tools/launchers/src/main/java/org/elasticsearch/tools/launchers/SystemJvmOptions.java

@@ -0,0 +1,70 @@
+/*
+ * Licensed to Elasticsearch under one or more contributor
+ * license agreements. See the NOTICE file distributed with
+ * this work for additional information regarding copyright
+ * ownership. Elasticsearch licenses this file to you under
+ * the Apache License, Version 2.0 (the "License"); you may
+ * not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *    http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing,
+ * software distributed under the License is distributed on an
+ * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+ * KIND, either express or implied.  See the License for the
+ * specific language governing permissions and limitations
+ * under the License.
+ */
+
+package org.elasticsearch.tools.launchers;
+
+import java.util.Arrays;
+import java.util.Collections;
+import java.util.List;
+
+final class SystemJvmOptions {
+
+    static List<String> systemJvmOptions() {
+        return Collections.unmodifiableList(Arrays.asList(
+            /*
+             * Cache ttl in seconds for positive DNS lookups noting that this overrides the JDK security property networkaddress.cache.ttl;
+             * can be set to -1 to cache forever.
+             */
+            "-Des.networkaddress.cache.ttl=60",
+            /*
+             * Cache ttl in seconds for negative DNS lookups noting that this overrides the JDK security property
+             * networkaddress.cache.negative ttl; set to -1 to cache forever.
+             */
+            "-Des.networkaddress.cache.negative.ttl=10",
+            // pre-touch JVM emory pages during initialization
+            "-XX:+AlwaysPreTouch",
+            // explicitly set the stack size
+            "-Xss1m",
+            // set to headless, just in case,
+            "-Djava.awt.headless=true",
+            // ensure UTF-8 encoding by default (e.g., filenames)
+            "-Dfile.encoding=UTF-8",
+            // use our provided JNA always versus the system one
+            "-Djna.nosys=true",
+            /*
+             * Turn off a JDK optimization that throws away stack traces for common exceptions because stack traces are important for
+             * debugging.
+             */
+            "-XX:-OmitStackTraceInFastThrow",
+            // flags to configure Netty
+            "-Dio.netty.noUnsafe=true",
+            "-Dio.netty.noKeySetOptimization=true",
+            "-Dio.netty.recycler.maxCapacityPerThread=0",
+            "-Dio.netty.allocator.numDirectArenas=0",
+            // log4j 2
+            "-Dlog4j.shutdownHookEnabled=false",
+            "-Dlog4j2.disable.jmx=true",
+            /*
+             * Due to internationalization enhancements in JDK 9 Elasticsearch need to set the provider to COMPAT otherwise time/date
+             * parsing will break in an incompatible way for some date patterns and locales.
+             */
+            "-Djava.locale.providers=SPI,COMPAT"));
+    }
+
+}