Add remark about reliability of System.gc() to

manager diagnostics docs.

git-svn-id: https://svn.apache.org/repos/asf/tomcat/trunk@915757 13f79535-47bb-0310-9956-ffa450edef68

diff --git a/webapps/docs/html-manager-howto.xml b/webapps/docs/html-manager-howto.xml
index d76af36..19d9301 100644 (file)
--- a/webapps/docs/html-manager-howto.xml
+++ b/webapps/docs/html-manager-howto.xml
@@ -558,6 +558,12 @@ with a profiler. The diagnostic uses additional functionality provided by the
 StandardHost implementation. It will not work if a custom host is used that
 does not extend StandardHost.</p>
 
+<p>Explicitely triggering a full garbage collection from Java Code is documented
+to be unreliable. Furthermore, depending on the JVM used, there are options to
+disable explicit GC triggering, like <code>-XX:+DisableExplicitGC</code>.
+If you want to make sure, that the diagnostics were successfully running a full GC,
+you will need to check using tools like GC logging, JConsole or simlar.</p>
+
 </section>
 
 <section name="Server Information">

diff --git a/webapps/docs/manager-howto.xml b/webapps/docs/manager-howto.xml
index 274aa24..c1c10dd 100644 (file)
--- a/webapps/docs/manager-howto.xml
+++ b/webapps/docs/manager-howto.xml
@@ -908,6 +908,12 @@ with a profiler. The diagnostic uses additional functionality provided by the
 StandardHost implementation. It will not work if a custom host is used that
 does not extend StandardHost.</p>
 
+<p>Explicitely triggering a full garbage collection from Java Code is documented
+to be unreliable. Furthermore, depending on the JVM used, there are options to
+disable explicit GC triggering, like <code>-XX:+DisableExplicitGC</code>.
+If you want to make sure, that the diagnostics were successfully running a full GC,
+you will need to check using tools like GC logging, JConsole or simlar.</p>
+
 <p>If this command succeeds, you will see a response like this:</p>
 <source>
 /leaking-webapp