Mateusz Łyczek created HADOOP-18174: ---------------------------------------
Summary: IBM Java detected while running on OpenJDK class library Key: HADOOP-18174 URL: https://issues.apache.org/jira/browse/HADOOP-18174 Project: Hadoop Common Issue Type: Bug Affects Versions: 3.3.2 Reporter: Mateusz Łyczek In our project we are using hadoop-client library and everything works fine while running inside containers with official OpenJDK base image. But for optimisation purposes we also use ibm-semeru-runtimes base images ([https://www.ibm.com/support/pages/semeru-runtimes-release-notes] ). To be specific we use *open-17.0.1_12-jre* version of this image and encountered the following problem. Our application is throwing an exception while using hadoop-client to upload files: {code:java} failure to login: javax.security.auth.login.LoginException: No LoginModule found for com.ibm.security.auth.module.JAASLoginModule{code} After a little investigation I found that this login module is selected by Hadoop only when it detects that it is being run on IBM Java (see [https://github.com/apache/hadoop/blob/672e380c4f6ffcb0a6fee6d8263166e16b4323c2/hadoop-common-project/hadoop-common/src/main/java/org/apache/hadoop/security/UserGroupInformation.java#L434] ) {code:java} private static String getOSLoginModuleName() { if (IBM_JAVA) { return "com.ibm.security.auth.module.JAASLoginModule"; } else { return windows ? "com.sun.security.auth.module.NTLoginModule" : "com.sun.security.auth.module.UnixLoginModule"; } } {code} and IBM Java is detected base on *java.vendor* system property value (see [https://github.com/apache/hadoop/blob/672e380c4f6ffcb0a6fee6d8263166e16b4323c2/hadoop-common-project/hadoop-auth/src/main/java/org/apache/hadoop/util/PlatformName.java#L50] ) {code:java} /** * The java vendor name used in this platform. */ public static final String JAVA_VENDOR_NAME = System.getProperty("java.vendor"); /** * A public static variable to indicate the current java vendor is * IBM java or not. */ public static final boolean IBM_JAVA = JAVA_VENDOR_NAME.contains("IBM"); {code} I checked inside the ibm-semeru-runtimes based version of our docker container and the *java.vendor* system property is set to the following value: {code:java} java.vendor: IBM Corporation {code} but, as the documentation for IBM Semeru runtimes images says, it contains OpenJDK class libraries with Eclipse OpenJ9 JVM. I confirmed it by running {*}java -version{*}: {code:java} openjdk version "17.0.1" 2021-10-19 IBM Semeru Runtime Open Edition 17.0.1.0 (build 17.0.1+12) Eclipse OpenJ9 VM 17.0.1.0 (build openj9-0.29.1, JRE 17 Linux amd64-64-Bit Compressed References 20211207_75 (JIT enabled, AOT enabled) OpenJ9 - 7d055dfcb OMR - e30892e2b JCL - fc67fbe50a0 based on jdk-17.0.1+12) {code} therefore there is no {{com.ibm.security.auth.module.JAASLoginModule}} class present. Therefore I would like to ask if there is any other way of detecting IBM java instead of checking the *java.vendor* system property, that would be more accurate? I tried to think about something to suggest - the first thing that came to my mind was to check if one of the classes from IBM packages actually exists by trying to load it but I don't know the other usages of the *IBM_JAVA* variable in hadoop-client, to be sure that it's a good idea for you. -- This message was sent by Atlassian Jira (v8.20.1#820001) --------------------------------------------------------------------- To unsubscribe, e-mail: common-issues-unsubscr...@hadoop.apache.org For additional commands, e-mail: common-issues-h...@hadoop.apache.org