Help Center/ MapReduce Service/ Component Operation Guide (Normal)/ Using MapReduce/ Common Issues About MapReduce/ What Should I Do If HDFS_DELEGATION_TOKEN Cannot Be Found in the Cache?
Updated on 2024-10-08 GMT+08:00
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What Should I Do If HDFS_DELEGATION_TOKEN Cannot Be Found in the Cache?

Question

Why cannot HDFS_DELEGATION_TOKEN be found in the cache in a cluster with Kerberos authentication enabled?

Answer

In MapReduce, HDFS_DELEGATION_TOKEN is deleted by default after a task is complete. If HDFS_DELEGATION_TOKEN is used in the next task, it will not be found in the cache.

To use the same token again in subsequent work, configure parameters for MapReduce tasks. If this parameter is set to false, the user can use the same token again.

jobConf.setBoolean("mapreduce.job.complete.cancel.delegation.tokens", false);