[feature] Allow the Java Garbage Collection implementation to be set.…

… Defaults to G1GC.
eXist-db · Apr 9, 2023 · 66ad438 · 66ad438
1 parent 351a6f7
commit 66ad438
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Showing 3 changed files with 23 additions and 2 deletions.
diff --git a/README.md b/README.md
@@ -121,14 +121,16 @@ details.
 Memory settings for this eXist-db instance. They map to the Java flags `-Xms`,
 `-Xmx`, `-XX:MaxMetaspaceSize` and `-XX:MaxDirectMemorySize`.
 
+    exist_mem_gc: 'g1'
     exist_mem_g1gc_pausegoal: 200
     exist_mem_gcdebug_enable: no
     exist_mem_nmt_enable: no
     exist_mem_strdedup_enable: yes
     exist_mem_niocachetune_enable: no
 
 Special memory settings suited for high-load installations:
-* `exist_mem_g1gc_pausegoal` is the value of Java option `-XX:MaxGCPauseMillis`
+* `exist_mem_gc` is the garbage collector to use, recognised values are: `serial`, `parallel`, `cms`, `g1`, `z`, and `shenandoah`.
+* `exist_mem_g1gc_pausegoal` is the value of Java option `-XX:MaxGCPauseMillis`; only relevant if `exist_mem_gc == 'g1'`.
 * `exist_mem_gcdebug_enable` enables GC logging for memory usage analysis
 * `exist_mem_nmt_enable` enable Java Native Memory Tracking. **NOTE** ignored for exist 4.x because of conflicts with the YAJSW wrapper
 * `exist_mem_strdedup_enable` enables Java String Deduplication

diff --git a/defaults/main.yml b/defaults/main.yml
@@ -40,6 +40,7 @@ exist_mem_max_meta: 1024
 exist_mem_max_direct: 1024
 
 # special memory/GC settings
+exist_mem_gc: 'g1'
 exist_mem_g1gc_pausegoal: 200
 exist_mem_gcdebug_enable: no
 exist_mem_nmt_enable: no

diff --git a/templates/exist.java.options.j2 b/templates/exist.java.options.j2
@@ -37,9 +37,27 @@
 -XX:MaxMetaspaceSize={{ exist_mem_max_meta }}m
 -XX:MaxDirectMemorySize={{ exist_mem_max_direct }}m
 
-# GC (default G1 GC)
+# GC
+{% if exist_mem_gc == 'serial' %}
+-XX:+UseSerialGC
+{% endif %}
+{% if exist_mem_gc == 'parallel' %}
+-XX:+UseParallelGC
+{% endif %}
+{% if exist_mem_gc == 'cms' %}
+-XX:+UseConcMarkSweepGC
+{% endif %}
+{% if exist_mem_gc == 'g1' %}
 -XX:+UseG1GC
 -XX:MaxGCPauseMillis={{ exist_mem_g1gc_pausegoal }}
+{% endif %}
+{% if exist_mem_gc == 'z' %}
+-XX:+UseZGC
+{% endif %}
+{% if exist_mem_gc == 'shenandoah' %}
+-XX:+UseShenandoahGC
+{% endif %}
+
 # GC logging/debugging
 {% if exist_mem_gcdebug_enable|bool is sameas true %}
 -XX:+PrintGCDetails