[
https://issues.apache.org/jira/browse/HDFS-13522?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=17691345#comment-17691345
]
Simbarashe Dzinamarira commented on HDFS-13522:
-----------------------------------------------
On the client side you need to set "dfs.client.rbf.observer.read.enable=true".
This lets the client use the ClientGSIContext which is needed to echo back
state to routers.
With the setting above you don't need to use the ObserverReadProxyProvider.
You are right that only new clients can use the observer reads through the
router. This is because clients need to echo back the namespace state using a
new field in the RPC header. The client side changes needs are fairly small
though. I testing with a private branch of 2.10.0.
> HDFS-13522: Add federated nameservices states to client protocol and
> propagate it between routers and clients.
> --------------------------------------------------------------------------------------------------------------
>
> Key: HDFS-13522
> URL: https://issues.apache.org/jira/browse/HDFS-13522
> Project: Hadoop HDFS
> Issue Type: Sub-task
> Components: federation, namenode
> Reporter: Erik Krogen
> Assignee: Simbarashe Dzinamarira
> Priority: Major
> Labels: pull-request-available
> Fix For: 3.4.0
>
> Attachments: HDFS-13522.001.patch, HDFS-13522.002.patch,
> HDFS-13522_WIP.patch, RBF_ Observer support.pdf, Router+Observer RPC
> clogging.png, ShortTerm-Routers+Observer.png,
> observer_reads_in_rbf_proposal_simbadzina_v1.pdf,
> observer_reads_in_rbf_proposal_simbadzina_v2.pdf
>
> Time Spent: 20h 50m
> Remaining Estimate: 0h
>
> Changes will need to occur to the router to support the new observer node.
> One such change will be to make the router understand the observer state,
> e.g. {{{}FederationNamenodeServiceState{}}}.
> This patch captures the state of all namespaces in the routers and propagates
> it to clients. A follow up patch will change router behavior to direct
> requests to the observer.
>
>
--
This message was sent by Atlassian Jira
(v8.20.10#820010)
---------------------------------------------------------------------
To unsubscribe, e-mail: [email protected]
For additional commands, e-mail: [email protected]
