Enable GC logging by default (3.0 version)

patch by Chris Lohfink; reviewed by aweisberg for CASSANDRA-10140

CHANGES.txt

@@ -11,6 +11,7 @@
  * (Hadoop) Close Clusters and Sessions in Hadoop Input/Output classes (CASSANDRA-10837)
  * Fix sstableloader not working with upper case keyspace name (CASSANDRA-10806)
 Merged from 2.2:
+ * Enable GC logging by default (CASSANDRA-10140)
  * Optimize pending range computation (CASSANDRA-9258)
  * Skip commit log and saved cache directories in SSTable version startup check (CASSANDRA-10902)
  * drop/alter user should be case sensitive (CASSANDRA-10817)

NEWS.txt

@@ -32,6 +32,8 @@ Upgrading
    - Custom index implementation should be aware that the method Indexer::indexes()
      has been removed as its contract was misleading and all custom implementation
      should have almost surely returned true inconditionally for that method.
+   - GC logging is now enabled by default (you can disable it in the jvm.options
+     file if you prefer).
 
 
 3.0

conf/cassandra-env.ps1

@@ -333,6 +333,9 @@ Function SetCassandraEnvironment
 
     ParseJVMInfo
 
+    #GC log path has to be defined here since it needs to find CASSANDRA_HOME
+    $env:JVM_OPTS="$env:JVM_OPTS -Xloggc:$env:CASSANDRA_HOME/logs/gc.log"
+
     # Read user-defined JVM options from jvm.options file
     $content = Get-Content "$env:CASSANDRA_CONF\jvm.options"
     for ($i = 0; $i -lt $content.Count; $i++)

conf/cassandra-env.sh

@@ -33,7 +33,7 @@ calculate_heap_sizes()
         Darwin)
             system_memory_in_bytes=`sysctl hw.memsize | awk '{print $2}'`
             system_memory_in_mb=`expr $system_memory_in_bytes / 1024 / 1024`
-            system_cpu_cores=`sysctl hw.ncpu | awk '{print $2}'`
+
         ;;
         *)
             # assume reasonable defaults for e.g. a modern desktop or
@@ -156,6 +156,9 @@ if [ "x$MALLOC_ARENA_MAX" = "x" ] ; then
     export MALLOC_ARENA_MAX=4
 fi
 
+#GC log path has to be defined here because it needs to access CASSANDRA_HOME
+JVM_OPTS="$JVM_OPTS -Xloggc:${CASSANDRA_HOME}/logs/gc.log"
+
 # Here we create the arguments that will get passed to the jvm when
 # starting cassandra.
 

conf/jvm.options

@@ -95,14 +95,14 @@
 
 ### GC logging options -- uncomment to enable
 
-#-XX:+PrintGCDetails
-#-XX:+PrintGCDateStamps
-#-XX:+PrintHeapAtGC
-#-XX:+PrintTenuringDistribution
-#-XX:+PrintGCApplicationStoppedTime
-#-XX:+PrintPromotionFailure
+-XX:+PrintGCDetails
+-XX:+PrintGCDateStamps
+-XX:+PrintHeapAtGC
+-XX:+PrintTenuringDistribution
+-XX:+PrintGCApplicationStoppedTime
+-XX:+PrintPromotionFailure
 #-XX:PrintFLSStatistics=1
 #-Xloggc:/var/log/cassandra/gc.log
-#-XX:+UseGCLogFileRotation
-#-XX:NumberOfGCLogFiles=10
-#-XX:GCLogFileSize=10M
+-XX:+UseGCLogFileRotation
+-XX:NumberOfGCLogFiles=10
+-XX:GCLogFileSize=10M

debian/patches/002cassandra_logdir_fix.dpatch

@@ -6,9 +6,9 @@
 
 @DPATCH@
 diff -urNad '--exclude=CVS' '--exclude=.svn' '--exclude=.git' '--exclude=.arch' '--exclude=.hg' '--exclude=_darcs' '--exclude=.bzr' cassandra~/bin/cassandra cassandra/bin/cassandra
---- cassandra~/bin/cassandra	2014-09-15 19:42:28.000000000 -0500
-+++ cassandra/bin/cassandra	2014-09-15 21:15:15.627505503 -0500
-@@ -134,7 +134,7 @@
+--- cassandra~/bin/cassandra	2015-10-27 14:35:22.000000000 -0500
++++ cassandra/bin/cassandra	2015-10-27 14:41:38.000000000 -0500
+@@ -139,7 +139,7 @@
      props="$3"
      class="$4"
      cassandra_parms="-Dlogback.configurationFile=logback.xml"
@@ -17,3 +17,15 @@ diff -urNad '--exclude=CVS' '--exclude=.svn' '--exclude=.git' '--exclude=.arch'
      cassandra_parms="$cassandra_parms -Dcassandra.storagedir=$cassandra_storagedir"
  
      if [ "x$pidpath" != "x" ]; then
+diff -urNad '--exclude=CVS' '--exclude=.svn' '--exclude=.git' '--exclude=.arch' '--exclude=.hg' '--exclude=_darcs' '--exclude=.bzr' cassandra~/conf/cassandra-env.sh cassandra/conf/cassandra-env.sh
+--- cassandra~/conf/cassandra-env.sh	2015-10-27 14:40:39.000000000 -0500
++++ cassandra/conf/cassandra-env.sh	2015-10-27 14:42:40.647449856 -0500
+@@ -204,7 +204,7 @@
+ esac
+ 
+ #GC log path has to be defined here because it needs to access CASSANDRA_HOME
+-JVM_OPTS="$JVM_OPTS -Xloggc:${CASSANDRA_HOME}/logs/gc.log"
++JVM_OPTS="$JVM_OPTS -Xloggc:/var/log/cassandra/gc.log"
+ 
+ # Here we create the arguments that will get passed to the jvm when
+ # starting cassandra.