chore: Raise max heap size of Elasticsearch to 512 MB

This value should be a sane default. Modern versions require more
resources, and nowadays any consumer hardware should be able to have
access to this amount of memory.

Additionally, do not set a lower bound on the heap size, so that unused
space isn't unnecessarily committed to the JVM.

README.md

@@ -349,10 +349,6 @@ of them require manual changes to the default ELK configuration.
 
 ### How to specify the amount of memory used by a service
 
-By default, both Elasticsearch and Logstash start with [1/4 of the total host
-memory](https://docs.oracle.com/javase/8/docs/technotes/guides/vm/gctuning/parallel.html#default_heap_size) allocated to
-the JVM Heap Size.
-
 The startup scripts for Elasticsearch and Logstash can append extra JVM options from the value of an environment
 variable, allowing the user to adjust the amount of memory that can be used by each component:
 
@@ -361,9 +357,10 @@ variable, allowing the user to adjust the amount of memory that can be used by e
 | Elasticsearch | ES_JAVA_OPTS         |
 | Logstash      | LS_JAVA_OPTS         |
 
-To accomodate environments where memory is scarce (Docker for Mac has only 2 GB available by default), the Heap Size
+To accomodate environments where memory is scarce (Docker Desktop for Mac has only 2 GB available by default), the Heap
-allocation is capped by default to 256MB per service in the `docker-compose.yml` file. If you want to override the
+Size allocation is capped by default in the `docker-compose.yml` file to 512 MB for Elasticsearch and 256 MB for
-default JVM configuration, edit the matching environment variable(s) in the `docker-compose.yml` file.
+Logstash. If you want to override the default JVM configuration, edit the matching environment variable(s) in the
+`docker-compose.yml` file.
 
 For example, to increase the maximum JVM Heap Size for Logstash:
 
@@ -371,9 +368,12 @@ For example, to increase the maximum JVM Heap Size for Logstash:
 logstash:
 
   environment:
-    LS_JAVA_OPTS: -Xmx1g -Xms1g
+    LS_JAVA_OPTS: -Xmx1g
 ```
 
+When these options are not set, both Elasticsearch and Logstash start with an upper cap of [1/4 of the total host
+memory][jvm-heap] set on the JVM Heap Size.
+
 ### How to enable a remote JMX connection to a service
 
 As for the Java Heap memory (see above), you can specify JVM options to enable JMX and map the JMX port on the Docker
@@ -436,3 +436,5 @@ See the following Wiki pages:
 [ls-docker]: https://www.elastic.co/guide/en/logstash/current/docker-config.html
 
 [upgrade]: https://www.elastic.co/guide/en/elasticsearch/reference/current/setup-upgrade.html
+
+[jvm-heap]: https://docs.oracle.com/en/java/javase/18/gctuning/parallel-collector1.html#GUID-74BE3BC9-C7ED-4AF8-A202-793255C864C4

docker-compose.yml

@@ -36,7 +36,7 @@ services:
       - "9200:9200"
       - "9300:9300"
     environment:
-      ES_JAVA_OPTS: -Xmx256m -Xms256m
+      ES_JAVA_OPTS: -Xmx512m
       # Bootstrap password.
       # Used to initialize the keystore during the initial startup of
       # Elasticsearch. Ignored on subsequent runs.
@@ -61,7 +61,7 @@ services:
       - "5000:5000/udp"
       - "9600:9600"
     environment:
-      LS_JAVA_OPTS: -Xmx256m -Xms256m
+      LS_JAVA_OPTS: -Xmx256m
       LOGSTASH_INTERNAL_PASSWORD: ${LOGSTASH_INTERNAL_PASSWORD:-}
     networks:
       - elk

extensions/enterprise-search/enterprise-search-compose.yml

@@ -9,7 +9,7 @@ services:
     volumes:
       - ./extensions/enterprise-search/config/enterprise-search.yml:/usr/share/enterprise-search/config/enterprise-search.yml:ro,Z
     environment:
-      JAVA_OPTS: -Xmx2g -Xms2g
+      JAVA_OPTS: -Xmx2g
       ENT_SEARCH_DEFAULT_PASSWORD: 'changeme'
       ELASTIC_PASSWORD: ${ELASTIC_PASSWORD:-}
     ports: