报错：Flink Hadoop is not in the classpath/dependencies

报错背景

安装Flink on yarn集群，Flink集群无法启动。

版本：

flink-1.14.4

hadoop-3.2.3

报错现象

2022-04-18 10:22:31,395 ERROR org.apache.flink.runtime.entrypoint.ClusterEntrypoint        [] - Could not start cluster entrypoint StandaloneSessionClusterEntrypoint.
org.apache.flink.runtime.entrypoint.ClusterEntrypointException: Failed to initialize the cluster entrypoint StandaloneSessionClusterEntrypoint.
    at org.apache.flink.runtime.entrypoint.ClusterEntrypoint.startCluster(ClusterEntrypoint.java:216) ~[flink-dist_2.12-1.14.4.jar:1.14.4]
    at org.apache.flink.runtime.entrypoint.ClusterEntrypoint.runClusterEntrypoint(ClusterEntrypoint.java:617) [flink-dist_2.12-1.14.4.jar:1.14.4]
    at org.apache.flink.runtime.entrypoint.StandaloneSessionClusterEntrypoint.main(StandaloneSessionClusterEntrypoint.java:59) [flink-dist_2.12-1.14.4.jar:1.14.4]
Caused by: java.io.IOException: Could not create FileSystem for highly available storage path (hdfs://flink/ha/default)
    at org.apache.flink.runtime.blob.BlobUtils.createFileSystemBlobStore(BlobUtils.java:92) ~[flink-dist_2.12-1.14.4.jar:1.14.4]
    at org.apache.flink.runtime.blob.BlobUtils.createBlobStoreFromConfig(BlobUtils.java:76) ~[flink-dist_2.12-1.14.4.jar:1.14.4]
    at org.apache.flink.runtime.highavailability.HighAvailabilityServicesUtils.createHighAvailabilityServices(HighAvailabilityServicesUtils.java:121) ~[flink-dist_2.12-1.14.4.jar:1.14.4]
    at org.apache.flink.runtime.entrypoint.ClusterEntrypoint.createHaServices(ClusterEntrypoint.java:361) ~[flink-dist_2.12-1.14.4.jar:1.14.4]
    at org.apache.flink.runtime.entrypoint.ClusterEntrypoint.initializeServices(ClusterEntrypoint.java:318) ~[flink-dist_2.12-1.14.4.jar:1.14.4]
    at org.apache.flink.runtime.entrypoint.ClusterEntrypoint.runCluster(ClusterEntrypoint.java:243) ~[flink-dist_2.12-1.14.4.jar:1.14.4]
    at org.apache.flink.runtime.entrypoint.ClusterEntrypoint.lambda$startCluster$1(ClusterEntrypoint.java:193) ~[flink-dist_2.12-1.14.4.jar:1.14.4]
    at org.apache.flink.runtime.security.contexts.NoOpSecurityContext.runSecured(NoOpSecurityContext.java:28) ~[flink-dist_2.12-1.14.4.jar:1.14.4]
    at org.apache.flink.runtime.entrypoint.ClusterEntrypoint.startCluster(ClusterEntrypoint.java:190) ~[flink-dist_2.12-1.14.4.jar:1.14.4]
    ... 2 more
Caused by: org.apache.flink.core.fs.UnsupportedFileSystemSchemeException: Could not find a file system implementation for scheme 'hdfs'. The scheme is not directly supported by Flink and no Hadoop file system to support this scheme could be loaded. For a full list of supported file systems, please see https://nightlies.apache.org/flink/flink-docs-stable/ops/filesystems/.
    at org.apache.flink.core.fs.FileSystem.getUnguardedFileSystem(FileSystem.java:532) ~[flink-dist_2.12-1.14.4.jar:1.14.4]
    at org.apache.flink.core.fs.FileSystem.get(FileSystem.java:409) ~[flink-dist_2.12-1.14.4.jar:1.14.4]
    at org.apache.flink.core.fs.Path.getFileSystem(Path.java:274) ~[flink-dist_2.12-1.14.4.jar:1.14.4]
    at org.apache.flink.runtime.blob.BlobUtils.createFileSystemBlobStore(BlobUtils.java:89) ~[flink-dist_2.12-1.14.4.jar:1.14.4]
    at org.apache.flink.runtime.blob.BlobUtils.createBlobStoreFromConfig(BlobUtils.java:76) ~[flink-dist_2.12-1.14.4.jar:1.14.4]
    at org.apache.flink.runtime.highavailability.HighAvailabilityServicesUtils.createHighAvailabilityServices(HighAvailabilityServicesUtils.java:121) ~[flink-dist_2.12-1.14.4.jar:1.14.4]
    at org.apache.flink.runtime.entrypoint.ClusterEntrypoint.createHaServices(ClusterEntrypoint.java:361) ~[flink-dist_2.12-1.14.4.jar:1.14.4]
    at org.apache.flink.runtime.entrypoint.ClusterEntrypoint.initializeServices(ClusterEntrypoint.java:318) ~[flink-dist_2.12-1.14.4.jar:1.14.4]
    at org.apache.flink.runtime.entrypoint.ClusterEntrypoint.runCluster(ClusterEntrypoint.java:243) ~[flink-dist_2.12-1.14.4.jar:1.14.4]
    at org.apache.flink.runtime.entrypoint.ClusterEntrypoint.lambda$startCluster$1(ClusterEntrypoint.java:193) ~[flink-dist_2.12-1.14.4.jar:1.14.4]
    at org.apache.flink.runtime.security.contexts.NoOpSecurityContext.runSecured(NoOpSecurityContext.java:28) ~[flink-dist_2.12-1.14.4.jar:1.14.4]
    at org.apache.flink.runtime.entrypoint.ClusterEntrypoint.startCluster(ClusterEntrypoint.java:190) ~[flink-dist_2.12-1.14.4.jar:1.14.4]
    ... 2 more
Caused by: org.apache.flink.core.fs.UnsupportedFileSystemSchemeException: Hadoop is not in the classpath/dependencies.
    at org.apache.flink.core.fs.UnsupportedSchemeFactory.create(UnsupportedSchemeFactory.java:55) ~[flink-dist_2.12-1.14.4.jar:1.14.4]
    at org.apache.flink.core.fs.FileSystem.getUnguardedFileSystem(FileSystem.java:528) ~[flink-dist_2.12-1.14.4.jar:1.14.4]
    at org.apache.flink.core.fs.FileSystem.get(FileSystem.java:409) ~[flink-dist_2.12-1.14.4.jar:1.14.4]
    at org.apache.flink.core.fs.Path.getFileSystem(Path.java:274) ~[flink-dist_2.12-1.14.4.jar:1.14.4]
    at org.apache.flink.runtime.blob.BlobUtils.createFileSystemBlobStore(BlobUtils.java:89) ~[flink-dist_2.12-1.14.4.jar:1.14.4]
    at org.apache.flink.runtime.blob.BlobUtils.createBlobStoreFromConfig(BlobUtils.java:76) ~[flink-dist_2.12-1.14.4.jar:1.14.4]
    at org.apache.flink.runtime.highavailability.HighAvailabilityServicesUtils.createHighAvailabilityServices(HighAvailabilityServicesUtils.java:121) ~[flink-dist_2.12-1.14.4.jar:1.14.4]
    at org.apache.flink.runtime.entrypoint.ClusterEntrypoint.createHaServices(ClusterEntrypoint.java:361) ~[flink-dist_2.12-1.14.4.jar:1.14.4]
    at org.apache.flink.runtime.entrypoint.ClusterEntrypoint.initializeServices(ClusterEntrypoint.java:318) ~[flink-dist_2.12-1.14.4.jar:1.14.4]
    at org.apache.flink.runtime.entrypoint.ClusterEntrypoint.runCluster(ClusterEntrypoint.java:243) ~[flink-dist_2.12-1.14.4.jar:1.14.4]
    at org.apache.flink.runtime.entrypoint.ClusterEntrypoint.lambda$startCluster$1(ClusterEntrypoint.java:193) ~[flink-dist_2.12-1.14.4.jar:1.14.4]
    at org.apache.flink.runtime.security.contexts.NoOpSecurityContext.runSecured(NoOpSecurityContext.java:28) ~[flink-dist_2.12-1.14.4.jar:1.14.4]
    at org.apache.flink.runtime.entrypoint.ClusterEntrypoint.startCluster(ClusterEntrypoint.java:190) ~[flink-dist_2.12-1.14.4.jar:1.14.4]
    ... 2 more

报错原因

Flink访问HDFS需要两个jar包依赖，Flink自身没有，需要自己放进去。

flink-shaded-hadoop-3-3.1.1.7.2.9.0-173-9.0.jar

commons-cli-1.5.0.jar

报错解决

直接在maven仓库里搜索这两个jar包即可下载：https://mvnrepository.com/

将jar包放入 /flink/lib 目录下。