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@mattisonchao mattisonchao commented May 11, 2022

Fixes #15539

Master Issue: #15539

Motivation

See #15539

Modifications

  • Add --add-opens java.base/sun.net=ALL-UNNAMED
  • Add --add-opens java.management/sun.management=ALL-UNNAMED

Verifying this change

  • Make sure that the change passes the CI checks.

Documentation

  • no-need-doc
  • doc-not-needed

@mattisonchao
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@heesung-sn
Please take a look, thanks.

@github-actions github-actions bot added the doc-not-needed Your PR changes do not impact docs label May 11, 2022
@heesung-sohn
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Thank you for taking care of this issue. I am wondering if removing reflection could resolve the issue too. Adding --add-opens seems radical unless required.

For example, can we directly use the static functions in InetAddressCachePolicy for this code?, https://github.com/openjdk/jdk17/blob/master/src/java.base/share/classes/sun/net/InetAddressCachePolicy.java#L154-L160

static {
        int ttl = DEFAULT_TTL;
        int negativeTtl = DEFAULT_NEGATIVE_TTL;
        try {
            // use reflection to call sun.net.InetAddressCachePolicy's get and getNegative methods for getting
            // effective JDK settings for DNS caching
            Class<?> inetAddressCachePolicyClass = Class.forName("sun.net.InetAddressCachePolicy");
            Method getTTLMethod = inetAddressCachePolicyClass.getMethod("get");
            ttl = (Integer) getTTLMethod.invoke(null);
            Method getNegativeTTLMethod = inetAddressCachePolicyClass.getMethod("getNegative");
            negativeTtl = (Integer) getNegativeTTLMethod.invoke(null);
        } catch (NoSuchMethodException | ClassNotFoundException | InvocationTargetException
                 | IllegalAccessException e) {
            log.warn("Cannot get DNS TTL settings from sun.net.InetAddressCachePolicy class", e);
        }
        TTL = useDefaultTTLWhenSetToForever(ttl, DEFAULT_TTL);
        NEGATIVE_TTL = useDefaultTTLWhenSetToForever(negativeTtl, DEFAULT_NEGATIVE_TTL);
    }

Similarly for this code path, we can use the static functions in ManagementFactoryHelper
https://github.com/openjdk/jdk17/blob/master/src/java.management/share/classes/sun/management/ManagementFactoryHelper.java

    private static Method getTotalSafepointTimeHandle;
    private static Method getSafepointCountHandle;

    private Map<String, GCMetrics> gcMetricsMap = new HashMap<>();

    static {
        try {
            runtime = Class.forName("sun.management.ManagementFactoryHelper")
                    .getMethod("getHotspotRuntimeMBean")
                    .invoke(null);
            getTotalSafepointTimeHandle = runtime.getClass().getMethod("getTotalSafepointTime");
            getTotalSafepointTimeHandle.setAccessible(true);
            getSafepointCountHandle = runtime.getClass().getMethod("getSafepointCount");
            getSafepointCountHandle.setAccessible(true);

            // try to use the methods
            getTotalSafepointTimeHandle.invoke(runtime);
            getSafepointCountHandle.invoke(runtime);
        } catch (Throwable e) {
            log.warn("Failed to get Runtime bean", e);
        }
    }

@mattisonchao mattisonchao marked this pull request as draft May 11, 2022 08:46
@lhotari
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lhotari commented May 11, 2022

#15349 is about DnsResolverUtil

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lhotari commented May 11, 2022

Thank you for taking care of this issue. I am wondering if removing reflection could resolve the issue too. Adding --add-opens seems radical unless required.

@heesung-sn The benefit of the reflection based solution is that it's possible to target Java 8 with --release 8 (maven.compiler.release) when compiling with Java 17. Since DnsResolverUtil must support targeting Java 8, I don't think we have another option than using the --add-opens solution for DnsResolverUtil.

IIRC, --add-exports will be needed at compile time when reflection isn't used and I don't think that is compatible with --release 8. That's the reason for the use of reflection in both of these cases.

It might be better to get rid of the sun.net.InetAddressPolicy class usage and just duplicate the logic in DnsResolverUtil.

@heesung-sohn
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@heesung-sn The benefit of the reflection based solution is that it's possible to target Java 8 with --release 8 (maven.compiler.release) when compiling with Java 17. Since DnsResolverUtil must support targeting Java 8, I don't think we have another option than using the --add-opens solution for DnsResolverUtil.

IIRC, --add-exports will be needed at compile time when reflection isn't used and I don't think that is compatible with --release 8. That's the reason for the use of reflection in both of these cases.

It might be better to get rid of the sun.net.InetAddressPolicy class usage and just duplicate the logic in DnsResolverUtil.

Ack. If there is no other option, I am ok with the --add-opens solution. Thank you for clarification.

@mattisonchao mattisonchao marked this pull request as ready for review May 11, 2022 23:39
@codelipenghui
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@mattisonchao Please help create a PR for branch-2.10, lots of conflicts when I cherry-picking this PR.

@Jason918
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@mattisonchao Please help create a PR for branch-2.10, lots of conflicts when I cherry-picking this PR.

+1 @mattisonchao

nicoloboschi pushed a commit to datastax/pulsar that referenced this pull request Jan 18, 2023
@liangyepianzhou
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@mattisonchao Please help create a PR for branch-2.10, lots of conflicts when I cherry-picking this PR.

+1 @mattisonchao I am cherry-picking this PR to branch-2.10. But I found the place of this PR modified does not exist in branch-2.10.
Could you please take a look at whether this Pr needs to cherry-pick to branch-2.10?

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JvmDefaultGCMetricsLogger cannot access class sun.management.ManagementFactoryHelper

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