Munin contributed plugins

Révision f0548a37

Fix jstat* plugins to work again with java 6+7, fix PU reporting for
Java8.

jstat column output is not stable across JVM versions (technically
version of jstat binary used).
New columns are added not add the end of column list but in the middle
breaking access via constant index.

Following table shows the known columns per version:
Oracle JDK / OpenJDK 1.5 .. 1.7
S0C S1C S0U S1U EC EU OC OU PC PU YGC YGCT FGC FGCT GCT
Openjdk 1.8 .. 10
S0C S1C S0U S1U EC EU OC OU MC MU CCSC CCSU YGC YGCT FGC FGCT GCT
Openjdk 11 .. 12
S0C S1C S0U S1U EC EU OC OU MC MU CCSC CCSU YGC YGCT FGC FGCT CGC CGCT GCT

Earlier commit here added support for java8+ but using version checking
if version == 1.5 > Use pre-java8 column format, else new format.

As fixing java6+7 would mean more version comparison which is ugly this
cmomit changes retrival logic to the following;
a.) Parse first line jstat output to find position for each label
b.) Then use that position to fetch value from 2nd line

That way code auto-adjusts to any ordering change without needing any
java version specific code or checks.

On the way fix 'Permanent Used' value reporting for java8 which was
broken (missing variable rename from PU -> MU when java8 support was
added).

#       Target Java Virtual Machine to monitor are:

#         Sun JDK 5.0 (http://java.sun.com/javase/)

#         Sun JDK 8.0 (http://java.sun.com/javase/)

#         OpenJDK 1.7 .. 11 (https://openjdk.java.net/)

#         BEA JRockit 5.0 (http://dev2dev.bea.com/jrockit/)

#

# Parameters:

    if "${JAVA_HOME}/bin/java" -version 2>&1 | grep -qi 'jrockit'; then

        echo "bea"

    else

        version=$("${JAVA_HOME}/bin/java" -version 2>&1 | grep '^java version' | awk '{print $3}' | sed -e 's/\"//g' | cut -d'_' -f 1)

        if echo "$version" | grep -q '^1\.5\.'; then

            echo "sun15"

        else

            echo "sun"

        fi

        echo "sun"

  fi

}

    if [ "${JDK_TYPE}" = "bea" ]; then

        # shellcheck disable=SC2016

        awk_script='{ YC = $4; OC = $5; print "Young_GC.value " YGC; print "Old_GC.value " FGC; }'

    elif [ "${JDK_TYPE}" = "sun15" ]; then

        # shellcheck disable=SC2016

        awk_script='{ YGC = $11; FGC = $13; print "Young_GC.value " YGC; print "Full_GC.value " FGC; }'

    else

        # example output of jstat for Java 1.8:

        #   S0C S1C S0U S1U EC EU OC OU MC MU CCSC CCSU YGC YGCT FGC FGCT GCT

        #   2048.0 2048.0 0.0 1344.0 694784.0 145013.5 1398272.0 414857.1 102400.0 96308.0 12544.0 11240.1 979 20.997 5 2.705 23.702

        # List & Order of columns of jstat changes with java versions

        # idx["YGC"] is index of YGC column in output (i.e. 13)

        # $idx["YGC"] then accesses the value at this position (taken from 2nd line of the output)

        # shellcheck disable=SC2016

        awk_script='{ YGC = $13; FGC = $15; print "Young_GC.value " YGC; print "Full_GC.value " FGC; }'

        awk_script='

            NR==1 { 

                for (i=1;i<=NF;i++) idx[$i]=i

            }

            NR==2 {

                print "Young_GC.value " $idx["YGC"];

                print "Full_GC.value " $idx["FGC"];

            }'

    fi

    "${JAVA_HOME}/bin/jstat" -gc "$pid_num" | tail -1 | awk "$awk_script"

    "${JAVA_HOME}/bin/jstat" -gc "$pid_num" | awk "$awk_script"

}

Formats disponibles : Unified diff