Guy Brand created MRESOLVER-153: ----------------------------------- Summary: resolver-status.properties file is corrupted due to concurrent writes Key: MRESOLVER-153 URL: https://issues.apache.org/jira/browse/MRESOLVER-153 Project: Maven Resolver Issue Type: Bug Components: Resolver Affects Versions: 1.6.1 Environment: OSX 11.1 on adoptopenjdk-11.0.8+10 Reporter: Guy Brand
In our integration tests which run with Maven {{4.0.0-alpha-1-SNAPSHOT}} after [this commit|https://github.com/apache/maven/commit/7c7de41562a8d83635e8fa21c3a3340298b508a1], we face the following error: {code:java} [main] [INFO] ------------------------------------------------------------------------ [main] [INFO] BUILD FAILURE [main] [INFO] ------------------------------------------------------------------------ [main] [INFO] Total time: 0.243 s [main] [INFO] Finished at: 2020-12-23T13:48:59+01:00 [main] [INFO] ------------------------------------------------------------------------ [main] [ERROR] Malformed \uxxxx encoding. java.lang.IllegalArgumentException: Malformed \uxxxx encoding. at java.util.Properties.loadConvert (Properties.java:675) at java.util.Properties.load0 (Properties.java:451) at java.util.Properties.load (Properties.java:404) at org.eclipse.aether.internal.impl.TrackingFileManager.read (TrackingFileManager.java:56) at org.eclipse.aether.internal.impl.DefaultUpdateCheckManager.read (DefaultUpdateCheckManager.java:511) at org.eclipse.aether.internal.impl.DefaultUpdateCheckManager.checkMetadata (DefaultUpdateCheckManager.java:250) at org.eclipse.aether.internal.impl.DefaultMetadataResolver.resolve (DefaultMetadataResolver.java:302) at org.eclipse.aether.internal.impl.DefaultMetadataResolver.resolveMetadata (DefaultMetadataResolver.java:181) at org.eclipse.aether.internal.impl.DefaultRepositorySystem.resolveMetadata (DefaultRepositorySystem.java:277) at org.apache.maven.plugin.version.internal.DefaultPluginVersionResolver.resolveFromRepository (DefaultPluginVersionResolver.java:134) at org.apache.maven.plugin.version.internal.DefaultPluginVersionResolver.resolve (DefaultPluginVersionResolver.java:97) at org.apache.maven.lifecycle.internal.LifecyclePluginResolver.resolveMissingPluginVersions (LifecyclePluginResolver.java:67) at org.apache.maven.lifecycle.internal.DefaultLifecycleTaskSegmentCalculator.calculateTaskSegments (DefaultLifecycleTaskSegmentCalculator.java:104) at org.apache.maven.lifecycle.internal.DefaultLifecycleTaskSegmentCalculator.calculateTaskSegments (DefaultLifecycleTaskSegmentCalculator.java:86) at org.apache.maven.lifecycle.internal.LifecycleStarter.execute (LifecycleStarter.java:92) at org.apache.maven.DefaultMaven.doExecute (DefaultMaven.java:321) at org.apache.maven.DefaultMaven.doExecute (DefaultMaven.java:206) at org.apache.maven.DefaultMaven.execute (DefaultMaven.java:119) at org.apache.maven.cli.MavenCli.execute (MavenCli.java:982) at org.apache.maven.cli.MavenCli.doMain (MavenCli.java:296) at org.apache.maven.cli.MavenCli.main (MavenCli.java:200) at jdk.internal.reflect.NativeMethodAccessorImpl.invoke0 (Native Method) at jdk.internal.reflect.NativeMethodAccessorImpl.invoke (NativeMethodAccessorImpl.java:62) at jdk.internal.reflect.DelegatingMethodAccessorImpl.invoke (DelegatingMethodAccessorImpl.java:43) at java.lang.reflect.Method.invoke (Method.java:566) at org.codehaus.plexus.classworlds.launcher.Launcher.launchEnhanced (Launcher.java:282) at org.codehaus.plexus.classworlds.launcher.Launcher.launch (Launcher.java:225) at org.codehaus.plexus.classworlds.launcher.Launcher.mainWithExitCode (Launcher.java:406) at org.codehaus.plexus.classworlds.launcher.Launcher.main (Launcher.java:347) {code} It's not consistently failing and OSX based CI agents fail more often than Linux or Windows ones. After some investigations we saw that as part of https://issues.apache.org/jira/browse/MRESOLVER-132 the synchronization has been removed on the {{TrackingFileManager}} ([https://github.com/apache/maven-resolver/pull/67]). This now leads to concurrent writes on the {{resolver-status.properties}} file in our tests and causes the error during the {{Properties#load()}} method wich then throws the above error. See this screenshot on how these files look like (cannot add the text here as {{null}} characters aren't shown): When enabling debug log we also see that the {{DefaultMetadataResolver}} threads try to write concurrently to this file: {code:java} [DefaultMetadataResolver-0-0] [INFO] Downloading from custom-repo2: https://repo.maven.apache.org/maven2/mng-xxxx-concurrent-writes-to-resolver-status-file/plugin/maven-metadata.xml [DefaultMetadataResolver-0-2] [INFO] Downloading from central-proxy: https://repo.maven.apache.org/maven2/mng-xxxx-concurrent-writes-to-resolver-status-file/plugin/maven-metadata.xml [DefaultMetadataResolver-0-1] [INFO] Downloading from custom-repo: https://repository.apache.org/snapshots/mng-xxxx-concurrent-writes-to-resolver-status-file/plugin/maven-metadata.xml [DefaultMetadataResolver-0-1] [DEBUG] Writing tracking file /.../core-it-suite/target/test-classes/mng-xxxx-concurrent-writes-to-resolver-status-file/repo/mng-xxxx-concurrent-writes-to-resolver-status-file/plugin/resolver-status.properties [DefaultMetadataResolver-0-2] [DEBUG] Writing tracking file /.../core-it-suite/target/test-classes/mng-xxxx-concurrent-writes-to-resolver-status-file/repo/mng-xxxx-concurrent-writes-to-resolver-status-file/plugin/resolver-status.properties [DefaultMetadataResolver-0-0] [DEBUG] Writing tracking file /.../core-it-suite/target/test-classes/mng-xxxx-concurrent-writes-to-resolver-status-file/repo/mng-xxxx-concurrent-writes-to-resolver-status-file/plugin/resolver-status.properties {code} We [created a Maven integration test|https://github.com/guylabs/maven-integration-testing/commit/56edeb28895a6704ad28e76655ee792d19797a8c] which reproduces the issue. The test is not always failing as in some runs the {{null}} characters are normalized to {{\u0000}} Strings and then written back to the {{resolver-status.properties}} file which then can be read properly by the {{Properties#load()}} method. You can monitor the {{core-it-suite/target/test-classes/mng-xxxx-concurrent-writes-to-resolver-status-file/repo/mng-xxxx-concurrent-writes-to-resolver-status-file/plugin/resolver-status.properties}} file while running the test as there you'll see the corrupted updates. Readding the thread synchronization to the {{TrackingFileManager}} would solve this race condition, as file locking is indeed not required as stated in MRESOLVER-132. Can we get this change into a new Maven {{4.0.0-alpha-1-SNAPSHOT}} version to be able to test the fix? -- This message was sent by Atlassian Jira (v8.3.4#803005)