How to clear EXPIRED routers?

[杨光]

Hi everyone!

I'm using hadoop 3.3.4, and started 5 hdfs routers on servers. Now I have
to delete two of them using: hdfs --daemon stop dfsrouter. The commend
executed successfully, but on router WebUI (http://url-to-router-webui:50071),
it shows 5 routers but 2 of them are on  EXPIRED status. How can I clear
them?

Re: DistCP from Hadoop 2.X to 3.X - where to compute

[杨光]

Hi PA,

We just did the same work recently, copying data from hadoop 2 to hadoop 3,
to be precise, src hadoop version was CDH hadoop-2.6 (5 hdfs nameservices
federation), dst hadoop version was hadoop 3.3.4. Both clusters are
protected with Kerberos, and of course, two realms have been trusted with
each other. We executed the DistCP on hadoop 3 version cluster, but also
tried on hadoop 2. Both were working nicely. I can confirm that copying
data with DistCP from 1.x to 2.x needs webhdfs, which is slow compared to
rpc one. Here is an execution example:

hadoop --config /home/hadoop/conf distcp \
  -Dmapreduce.job.hdfs-servers.token-renewal.exclude=ns1,ns2,ns3,ns4,ns5 \
  -update -skipcrccheck \
  hdfs://hadoop2-cluster/user/test \
  hdfs://hadoop3-cluster/user/test