Remove implicit 32-bit support

We previously tried to maintain (while not formally supporting) 32-bit
support, although we never tested this anywhere in CI. Since we do not
formally support this, and 32-bit usage is very low, we have elected to
no longer maintain 32-bit support. This commit removes any implication
of 32-bit support.

Relates #25435

core/src/main/java/org/elasticsearch/bootstrap/SystemCallFilter.java

@@ -242,7 +242,6 @@ final class SystemCallFilter {
     static {
         Map<String,Arch> m = new HashMap<>();
         m.put("amd64", new Arch(0xC000003E, 0x3FFFFFFF, 57, 58, 59, 322, 317));
-        m.put("i386",  new Arch(0x40000003, 0xFFFFFFFF, 2, 190, 11, 358, 354));
         ARCHITECTURES = Collections.unmodifiableMap(m);
     }
 

distribution/src/main/resources/bin/elasticsearch-service.bat

@@ -27,29 +27,13 @@ if not "%CONF_FILE%" == "" goto conffileset
 set SCRIPT_DIR=%~dp0
 for %%I in ("%SCRIPT_DIR%..") do set ES_HOME=%%~dpfI
 
-%JAVA% -Xmx50M -version > nul 2>&1
-
-if errorlevel 1 (
-	echo Warning: Could not start JVM to detect version, defaulting to x86:
-	goto x86
-)
-
-%JAVA% -Xmx50M -version 2>&1 | "%windir%\System32\find" "64-Bit" >nul:
-
-if errorlevel 1 goto x86
 set EXECUTABLE=%ES_HOME%\bin\elasticsearch-service-x64.exe
 set SERVICE_ID=elasticsearch-service-x64
 set ARCH=64-bit
-goto checkExe
-
-:x86
-set EXECUTABLE=%ES_HOME%\bin\elasticsearch-service-x86.exe
-set SERVICE_ID=elasticsearch-service-x86
-set ARCH=32-bit
 
-:checkExe
 if EXIST "%EXECUTABLE%" goto okExe
-echo elasticsearch-service-(x86|x64).exe was not found...
+echo elasticsearch-service-x64.exe was not found...
+exit /B 1
 
 :okExe
 set ES_VERSION=${project.version}

distribution/src/main/resources/config/jvm.options

@@ -47,10 +47,10 @@
 
 ## basic
 
-# force the server VM (remove on 32-bit client JVMs)
+# force the server VM
 -server
 
-# explicitly set the stack size (reduce to 320k on 32-bit client JVMs)
+# explicitly set the stack size
 -Xss1m
 
 # set to headless, just in case

docs/reference/migration/migrate_6_0/packaging.asciidoc

@@ -29,3 +29,9 @@ removed and now data paths and log paths can be configured via settings
 only. Related, this means that the environment variables `DATA_DIR` and
 `LOG_DIR` no longer have any effect as these were used to set
 `default.path.data` and `default.path.logs` in the packaging scripts.
+
+==== 32-bit is no longer maintained
+
+We previously attempted to ensure that Elasticsearch could be started on 32-bit
+JVM (although a bootstrap check prevented using a 32-bit JVM in production). We
+are no longer maintaining this attempt.

docs/reference/setup.asciidoc

@@ -34,10 +34,6 @@ refuse to start if a known-bad version of Java is used.
 The version of Java that Elasticsearch will use can be configured by setting
 the `JAVA_HOME` environment variable.
 
-NOTE: Elasticsearch ships with default configuration for running Elasticsearch on 64-bit server JVMs. If you are using a 32-bit client JVM,
-you must remove `-server` from <<jvm-options,jvm.options>> and if you are using any 32-bit JVM you should reconfigure the thread stack size
-from `-Xss1m` to `-Xss320k`.
-
 --
 
 include::setup/install.asciidoc[]

docs/reference/setup/install/zip-windows.asciidoc

@@ -111,9 +111,7 @@ The commands available are:
 
 `manager`:: Start a GUI for managing the installed service
 
-Based on the architecture of the available JDK/JRE (set through `JAVA_HOME`),
-the appropriate 64-bit(x64) or 32-bit(x86) service will be installed. This
-information is made available during install:
+The name of the service and the value of `JAVA_HOME` will be made available during install:
 
 ["source","sh",subs="attributes"]
 --------------------------------------------------
@@ -141,7 +139,8 @@ The Elasticsearch service can be configured prior to installation by setting the
 [horizontal]
 `SERVICE_ID`::
 
-  A unique identifier for the service.  Useful if installing multiple instances on the same machine.  Defaults to `elasticsearch-service-x86` (on 32-bit Windows) or `elasticsearch-service-x64` (on 64-bit Windows).
+  A unique identifier for the service. Useful if installing multiple instances
+  on the same machine. Defaults to `elasticsearch-service-x64`.
 
 `SERVICE_USERNAME`::