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Siyao Meng commented on HADOOP-16656: ------------------------------------- [~dineshchitlangia] Thanks for the comment. Yes, in the most typical usage of FairCallQueue, {{[port_number]}} should be set to the NN RPC port (in {{dfs.namenode.rpc-address}}). But I don't really see anything preventing users from setting {{[port_number]}} to NN service RPC port (in dfs.namenode.servicerpc-address) or lifeline port (in {{dfs.namenode.lifeline.rpc-address}}). So I tested (trunk) locally with 1 NN and 1 DN, (1) {{[port_number]}} can be set to NN RPC port (in {{dfs.namenode.rpc-address}}) *without* setting a NN service RPC address/port ({{dfs.namenode.servicerpc-address}}); (2) {{[port_number]}} can be set to NN service RPC port (in {{dfs.namenode.servicerpc-address}}); (3) {{[port_number]}} can be set to NN lifeline RPC port (in {{dfs.namenode.lifeline.rpc-address}}); In all 3 cases above, I can start NN and DN, and successfully run a shell command "{{hdfs dfs -ls /}}" with the NN. One explanation is that, even if {{ipc.[port_number].callqueue.impl}} is *not* set, it defaults to {{LinkedBlockingQueue}}, as shown in the code [here|https://github.com/apache/hadoop/blob/1654497f98fb7f2de8214d2fbad305b7a2854816/hadoop-common-project/hadoop-common/src/main/java/org/apache/hadoop/ipc/Server.java#L691]. So in theory, {{[port_number]}} could be set to any RPC port opened on NN. I haven't dug into FairCallQueue implementation in its entirety - there might be some other exceptions I didn't realize. Instead, we could remind users that they typically want to set {{[port_number]}} to NN RPC port rather than the other two (NN service RPC port, or lifeline port)? > Document FairCallQueue configs in core-default.xml > -------------------------------------------------- > > Key: HADOOP-16656 > URL: https://issues.apache.org/jira/browse/HADOOP-16656 > Project: Hadoop Common > Issue Type: Task > Reporter: Siyao Meng > Assignee: Siyao Meng > Priority: Major > Attachments: HADOOP-16656.001.patch > > > So far those callqueue / scheduler / faircallqueue -related configurations > are only documented in FairCallQueue.md in 3.3.0: > https://aajisaka.github.io/hadoop-document/hadoop-project/hadoop-project-dist/hadoop-common/FairCallQueue.html#Full_List_of_Configurations > (Thanks Akira for uploading this.) > Goal: Document those configs in core-default.xml as well to make it easier > for users(admins) to find and use. -- This message was sent by Atlassian Jira (v8.3.4#803005) --------------------------------------------------------------------- To unsubscribe, e-mail: common-issues-unsubscr...@hadoop.apache.org For additional commands, e-mail: common-issues-h...@hadoop.apache.org