Uploaded image for project: 'JDK'
  1. JDK
  2. JDK-8220674

[TESTBUG] MetricsMemoryTester failcount test in docker container only works with debug JVMs

    Details

    • Resolved In Build:
      b14
    • CPU:
      generic
    • OS:
      linux

      Backports

        Description

        The test failure due to this is as follows (TestDockerMemoryMetrics.java):

        ========== NEW TEST CASE: testMemoryFailCount20m
        [COMMAND]
        docker run --tty=true --rm --volume /disk/openjdk/upstream-sources/openjdk-head-2/JTwork/test_jdk/classes/jdk/internal/platform/docker/TestDockerMemoryMetrics.d:/test-classes/ --memory=20m jdk-internal:test-metrics-memory /jdk/bin/java -cp /test-classes/ --add-exports java.base/jdk.internal.platform=ALL-UNNAMED MetricsMemoryTester failcount
        [ELAPSED: 2 ms]
        [STDERR]

        [STDOUT]
        [failcount]
        Exception in thread "main" java.lang.RuntimeException: Memory fail count : new : [0], old : [0]
        at MetricsMemoryTester.testMemoryFailCount(MetricsMemoryTester.java:77)
        at MetricsMemoryTester.main(MetricsMemoryTester.java:44)

        What's happening?

        MetricsMemoryTester's failcount test looks like this:

            private static void testMemoryFailCount() {
                long count = Metrics.systemMetrics().getMemoryFailCount();

                // Allocate 512M of data
                long[][] longs = new long[64][];
                for (int i = 1; i <= 64; i++) {
                    try {
                        longs[i] = new long[8 * 1024 * 1024];
                    } catch (Error e) { // OOM error
                        break;
                    }
                }
                if (Metrics.systemMetrics().getMemoryFailCount() <= count) {
                    throw new RuntimeException("Memory fail count : new : ["
                            + Metrics.systemMetrics().getMemoryFailCount() + "]"
                            + ", old : [" + count + "]");
                }
                System.out.println("TEST PASSED!!!");
            }

        Two issues:

        1. The test assumes this piece of code increases memory.failcnt:
             long[][] longs = new long[64][];
                for (int i = 1; i <= 64; i++) {
                    try {
                        longs[i] = new long[8 * 1024 * 1024];
                    } catch (Error e) { // OOM error
                        break;
                    }
               }

        It doesn't, though. At least for me on Fedora 29. Building a container as below does not increase the memory.failcnt counter unless the JDK under test is a fastdebug or debug JVM:

        $ cat Dockerfile
        FROM fedora:29
        RUN dnf install -y java-1.8.0-openjdk-devel && \
            dnf -y clean all
        ADD fastdebug-jdk /fastdebug-jdk
        ADD release-jdk /release-jdk
        ADD Memory.class /opt
        CMD /bin/bash
        $ cat Memory.java
        public class Memory {

        public static void main(String[] args) {
                long[][] longs = new long[64][];
                for (int i = 1; i <= 64; i++) {
                    try {
                        longs[i] = new long[8 * 1024 * 1024];
                    } catch (Error e) { // OOM error
        e.printStackTrace();
                        break;
                    }
                }

        }
        }
        $ javac Memory.java
        $ sudo docker build -t fedora-memory-test:v3 .
        $ sudo docker run -ti --memory 20m --memory-swap 0 fedora-memory-test:v3 /bin/bash
        [root@63f527777700 /]# cat /sys/fs/cgroup/memory/memory.failcnt
        0
        [root@63f527777700 /]# cd opt
        [root@63f527777700 opt]# /release-jdk/bin/java Memory
        java.lang.OutOfMemoryError: Java heap space
        at Memory.main(Memory.java:7)
        [root@63f527777700 opt]# cat /sys/fs/cgroup/memory/memory.failcnt
        0
        [root@63f527777700 opt]# /fastdebug-jdk/bin/java Memory
        java.lang.OutOfMemoryError: Java heap space
        at Memory.main(Memory.java:7)
        [root@63f527777700 opt]# cat /sys/fs/cgroup/memory/memory.failcnt
        1257

        2. The loop counter is wrong. Goes from 1 to 64. Should be 0 to 63. ArrayIndexOutOfBoundsException is thrown otherwise. Not really related to this problem, though.

          Attachments

            Issue Links

              Activity

                People

                • Assignee:
                  bobv Bob Vandette
                  Reporter:
                  sgehwolf Severin Gehwolf
                • Votes:
                  0 Vote for this issue
                  Watchers:
                  2 Start watching this issue

                  Dates

                  • Created:
                    Updated:
                    Resolved: