This is an automated email from the ASF dual-hosted git repository.
dbarnes pushed a commit to branch support/1.15
in repository https://gitbox.apache.org/repos/asf/geode.git
The following commit(s) were added to refs/heads/support/1.15 by this push:
new 8cc780a557 GEODE-10385: User Guide - Remove bad G1GC tuning advice
(#7815)
8cc780a557 is described below
commit 8cc780a557ad9052a27c12de00e18ac0bdf1016c
Author: Dave Barnes <[email protected]>
AuthorDate: Thu Jun 23 09:59:03 2022 -0700
GEODE-10385: User Guide - Remove bad G1GC tuning advice (#7815)
---
geode-docs/managing/heap_use/heap_management.html.md.erb | 1 -
1 file changed, 1 deletion(-)
diff --git a/geode-docs/managing/heap_use/heap_management.html.md.erb
b/geode-docs/managing/heap_use/heap_management.html.md.erb
index 682d7113e9..b138716574 100644
--- a/geode-docs/managing/heap_use/heap_management.html.md.erb
+++ b/geode-docs/managing/heap_use/heap_management.html.md.erb
@@ -153,7 +153,6 @@ $ gfsh start server --name=app.MyApplication
--initial-heap=30m --max-heap=30m \
Although the garbage first (G1) garbage collector works effectively with
<%=vars.product_name_long%>, issues can arise in some cases due to the
differences between CMS and G1.
For example, G1 by design is not able to set a maximum tenured heap size, so
when this value is requested from the garbage collector, it reports the total
heap maximum size. This impacts <%=vars.product_name_long%>, as the resource
manager uses the maximum size of the tenured heap size to calculate the value
in bytes of the eviction and critical percentages.
Extensive testing is recommended before using G1 garbage collector. See your
JVM documentation for all JVM-specific settings that can be used to improve
garbage collection (GC) response.
-If you find the <%=vars.product_name_long%> Resource Manager does not detect
crossing the eviction or critical threshold quickly enough, it has been
observed that its responsiveness is increased by reducing the default value of
`--J-XX:MaxGCPauseMillis=VALUE` JVM parameter (which is `200`). Be sure to take
into account that this change also increases the amount of time spent in
garbage collection.
Size of objects stored on a region must also be taken into account. If the
primary heap objects you allocate are larger than 50 percent of the G1 region
size (what are called "humongous" objects), this can cause the JVM to report
`out of heap memory` when it has used only 50 percent of the heap.
The default G1 region size is 1 Mb; it can be increased up to 32 Mb (with
values that are always a power of 2) by using the
`--J-XX:G1HeapRegionSize=VALUE` JVM parameter. If you are using large objects
and want to use G1GC without increasing its heap region size (or if your values
are larger than 16 Mb), then you could configure your
<%=vars.product_name_long%> regions to store the large values off-heap.
However, even if you do that the large off-heap values will allocate large
temporary [...]
