Hi@akhtar,
I think you are trying to use AsyncFSWAL for HBase-2.x as it has better performance while consuming less resources. But the problem for AsyncFSWAL is that it hacks into the internal of the DFSClient implementation, so it will easily be broken when upgrading hadoop, even for a simple patch release.
To avoid this error you have to specify FSHLog, i.e, filesystem, explicitly in your config file.
<property>
<name>hbase.wal.provider</name>
<value>filesystem</value>
</property>
Hope this will help.