[FLINK-25099] flink on yarn Accessing two HDFS Clusters

• Type: Bug
• Status: Open
• Priority: Major
• Resolution: Unresolved
• Affects Version/s: 1.13.3
• Component/s: Deployment / YARN, FileSystems, Runtime / Checkpointing

Environment

flink : 1.13.3
hadoop : 3.3.0

• Assignee: Unassigned
• Reporter: Qizhu Chan
• Created: 30/Nov/21 02:17
• Updated: 28/Jan/22 09:01

Description

Flink version 1.13 supports configuration of Hadoop properties in flink-conf.yaml via flink.hadoop.*. There is A requirement to write checkpoint to HDFS with SSDS (called cluster B) to speed checkpoint writing, but this HDFS cluster is not the default HDFS in the flink client (called cluster A by default). Yaml is configured with nameservices for cluster A and cluster B, which is similar to HDFS federated mode.

The configuration is as follows:

 

flink.hadoop.dfs.nameservices: ACluster,BCluster
flink.hadoop.fs.defaultFS: hdfs://BCluster

flink.hadoop.dfs.ha.namenodes.ACluster: nn1,nn2
flink.hadoop.dfs.namenode.rpc-address.ACluster.nn1: 10.xxxx:9000
flink.hadoop.dfs.namenode.http-address.ACluster.nn1: 10.xxxx:50070
flink.hadoop.dfs.namenode.rpc-address.ACluster.nn2: 10.xxxxxx:9000
flink.hadoop.dfs.namenode.http-address.ACluster.nn2: 10.xxxxxx:50070
flink.hadoop.dfs.client.failover.proxy.provider.ACluster: org.apache.hadoop.hdfs.server.namenode.ha.ConfiguredFailoverProxyProvider

flink.hadoop.dfs.ha.namenodes.BCluster: nn1,nn2
flink.hadoop.dfs.namenode.rpc-address.BCluster.nn1: 10.xxxxxx:9000
flink.hadoop.dfs.namenode.http-address.BCluster.nn1: 10.xxxxxx:50070
flink.hadoop.dfs.namenode.rpc-address.BCluster.nn2: 10.xxxxxx:9000
flink.hadoop.dfs.namenode.http-address.BCluster.nn2: 10.xxxxx:50070
flink.hadoop.dfs.client.failover.proxy.provider.BCluster: org.apache.hadoop.hdfs.server.namenode.ha.ConfiguredFailoverProxyProvider

 

However, an error occurred during the startup of the job, which is reported as follows:

(change configuration items to A flink local client default HDFS cluster, the operation can be normal boot:  flink.hadoop.fs.DefaultFS: hdfs: / / ACluster)

Caused by: BCluster
java.net.UnknownHostException: BCluster
at org.apache.hadoop.security.SecurityUtil.buildTokenService(SecurityUtil.java:448)
at org.apache.hadoop.hdfs.NameNodeProxiesClient.createProxyWithClientProtocol(NameNodeProxiesClient.java:139)
at org.apache.hadoop.hdfs.DFSClient.<init>(DFSClient.java:374)
at org.apache.hadoop.hdfs.DFSClient.<init>(DFSClient.java:308)
at org.apache.hadoop.hdfs.DistributedFileSystem.initialize(DistributedFileSystem.java:184)
at org.apache.hadoop.fs.FileSystem.createFileSystem(FileSystem.java:3414)
at org.apache.hadoop.fs.FileSystem.access$200(FileSystem.java:158)
at org.apache.hadoop.fs.FileSystem$Cache.getInternal(FileSystem.java:3474)
at org.apache.hadoop.fs.FileSystem$Cache.get(FileSystem.java:3442)
at org.apache.hadoop.fs.FileSystem.get(FileSystem.java:524)
at org.apache.hadoop.fs.Path.getFileSystem(Path.java:365)
at org.apache.hadoop.yarn.util.FSDownload.verifyAndCopy(FSDownload.java:270)
at org.apache.hadoop.yarn.util.FSDownload.access$000(FSDownload.java:68)
at org.apache.hadoop.yarn.util.FSDownload$2.run(FSDownload.java:415)
at org.apache.hadoop.yarn.util.FSDownload$2.run(FSDownload.java:412)
at java.security.AccessController.doPrivileged(Native Method)
at javax.security.auth.Subject.doAs(Subject.java:422)
at org.apache.hadoop.security.UserGroupInformation.doAs(UserGroupInformation.java:1845)
at org.apache.hadoop.yarn.util.FSDownload.call(FSDownload.java:412)
at org.apache.hadoop.yarn.server.nodemanager.containermanager.localizer.ContainerLocalizer$FSDownloadWrapper.doDownloadCall(ContainerLocalizer.java:247)
at org.apache.hadoop.yarn.server.nodemanager.containermanager.localizer.ContainerLocalizer$FSDownloadWrapper.call(ContainerLocalizer.java:240)
at org.apache.hadoop.yarn.server.nodemanager.containermanager.localizer.ContainerLocalizer$FSDownloadWrapper.call(ContainerLocalizer.java:228)
at java.util.concurrent.FutureTask.run(FutureTask.java:266)
at java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:511)
at java.util.concurrent.FutureTask.run(FutureTask.java:266)
at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1142)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:617)
at java.lang.Thread.run(Thread.java:745)

Is there a solution to the above problems? The pain point is that Flink can access two HDFS clusters, preferably through the configuration of Flink-conf. yaml.