Hi Tan, Wangda,
As per earlier offline discussion, i have created the patch for supporting Labels To Nodes Mapping in REST. Please review

-1 overall. Here are the results of testing the latest attachment
http://issues.apache.org/jira/secure/attachment/12703640/YARN-3326.20150310-1.patch
against trunk revision 7711049.

+1 @author. The patch does not contain any @author tags.

+1 tests included. The patch appears to include 1 new or modified test files.

+1 javac. The applied patch does not increase the total number of javac compiler warnings.

+1 javadoc. There were no new javadoc warning messages.

+1 eclipse:eclipse. The patch built with eclipse:eclipse.

-1 findbugs. The patch appears to introduce 5 new Findbugs (version 2.0.3) warnings.

+1 release audit. The applied patch does not increase the total number of release audit warnings.

-1 core tests. The patch failed these unit tests in hadoop-yarn-project/hadoop-yarn/hadoop-yarn-server/hadoop-yarn-server-resourcemanager:

org.apache.hadoop.yarn.server.resourcemanager.TestRM

Test results: https://builds.apache.org/job/PreCommit-YARN-Build/6901//testReport/
Findbugs warnings: https://builds.apache.org/job/PreCommit-YARN-Build/6901//artifact/patchprocess/newPatchFindbugsWarningshadoop-yarn-server-resourcemanager.html
Console output: https://builds.apache.org/job/PreCommit-YARN-Build/6901//console

This message is automatically generated.

TEstcase failure (TestRM failure) and findbugs issues are not related to this patch.

Naganarasimha G R - can we change the endpoint from "/get-labels-to-Nodes" to a more RESTful name. Something like "/labels/nodes?labels=<nodes>"?

Thanks Varun Vasudev for reviewing it .

Something like "/labels/nodes?labels=<nodes>"

Idea here is , user can pass specific labels(optionally) of his interest so that he gets back the node's(NodeID strings) for each labels. So even if we model it as per your naming convention it will be "/labels/nodes?labels=<label1,label2, ...>".

Also "/labels/nodes" seems like nodes are subcategory of Labels but actually we are just getting Labels to Nodes mapping. So i feel its better as "/labelsToNodes?labels=<label1,label2, ...>"

I had modelled this method based on the existing method to REST name mappings :

"getNodeToLabels" to "/get-node-to-labels"
"replaceLabelsOnNodes" to "/replace-node-to-labels"
"getClusterNodeLabels" to "/get-node-labels"
"addToClusterNodeLabels " to "/add-node-labels"
"removeFromCluserNodeLabels" to "/remove-node-labels"
"getLabelsOnNode" to "/nodes/{nodeId}/get-labels"
"replaceLabelsOnNodes" to "/replace-node-to-labels" ...

So i feel its better to keep in sync in all places, but can we change existing mappings now or would it be ok to have just one method modified ?

How about "/nodes?labels=label1,label2" etc? If I understand it right - you want to give a list of labels and get the nodes back for those labels, so "/nodes?labels=" form should work?

Hi Varun Vasudev, consider the scenario where user wants for all labels and hence does not pass any labels ?
In that case the url will be just "/nodes" which i feel not so good , ur thoughts?

Will "/nodes?labels=*" work?

Well Varun Vasudev, i feel "/nodes" would be better than having internal logic for " * " and checked again and saw that "/nodes" is already used for getNodes but what abt "/labelsToNodes" or "/labels-to-nodes" you feel this is big ?

In general REST APIs are supposed to be about resources. "labelsToNodes" is not a resource.

"getNodeToLabels" to "/get-node-to-labels"
"replaceLabelsOnNodes" to "/replace-node-to-labels"
"getClusterNodeLabels" to "/get-node-labels"
"addToClusterNodeLabels " to "/add-node-labels"
"removeFromCluserNodeLabels" to "/remove-node-labels"
"getLabelsOnNode" to "/nodes/{nodeId}/get-labels"
"replaceLabelsOnNodes" to "/replace-node-to-labels" ...

are not about resources either but they're already in and by adding more APIs of that form we're making things worse.

Varun Vasudev How about "/label-mappings?label=label1,label2,..." ?

Hi Varun Vasudev, Tan, Wangda, I was not able to come up with anything better than "/label-mappings?label=label1,label2,...", please inform if this is ok will modify the patch else please provide more options...
P.S. "/nodes" is already used for getNodes

Have modified the patch assuming that "/label-mappings" is good enough ... please feedback !

+1 overall. Here are the results of testing the latest attachment
http://issues.apache.org/jira/secure/attachment/12723771/YARN-3326.20150407-1.patch
against trunk revision bd77a7c.

+1 @author. The patch does not contain any @author tags.

+1 tests included. The patch appears to include 1 new or modified test files.

+1 javac. The applied patch does not increase the total number of javac compiler warnings.

+1 javadoc. There were no new javadoc warning messages.

+1 eclipse:eclipse. The patch built with eclipse:eclipse.

+1 findbugs. The patch does not introduce any new Findbugs (version 2.0.3) warnings.

+1 release audit. The applied patch does not increase the total number of release audit warnings.

+1 core tests. The patch passed unit tests in hadoop-yarn-project/hadoop-yarn/hadoop-yarn-server/hadoop-yarn-server-resourcemanager.

Test results: https://builds.apache.org/job/PreCommit-YARN-Build/7248//testReport/
Console output: https://builds.apache.org/job/PreCommit-YARN-Build/7248//console

This message is automatically generated.

Naganarasimha G R thank you for updating. LGTM overall.

Minor nits: let's avoid using * import.

+import java.util.*;

Thanks for reviewing Tsuyoshi Ozawa , have updated the patch with your review comment

-1 overall. Here are the results of testing the latest attachment
http://issues.apache.org/jira/secure/attachment/12723819/YARN-3326.20150408-1.patch
against trunk revision 4be648b.

+1 @author. The patch does not contain any @author tags.

+1 tests included. The patch appears to include 1 new or modified test files.

+1 javac. The applied patch does not increase the total number of javac compiler warnings.

+1 javadoc. There were no new javadoc warning messages.

+1 eclipse:eclipse. The patch built with eclipse:eclipse.

+1 findbugs. The patch does not introduce any new Findbugs (version 2.0.3) warnings.

+1 release audit. The applied patch does not increase the total number of release audit warnings.

-1 core tests. The patch failed these unit tests in hadoop-yarn-project/hadoop-yarn/hadoop-yarn-server/hadoop-yarn-server-resourcemanager:

org.apache.hadoop.yarn.server.resourcemanager.TestRMRestart

Test results: https://builds.apache.org/job/PreCommit-YARN-Build/7250//testReport/
Console output: https://builds.apache.org/job/PreCommit-YARN-Build/7250//console

This message is automatically generated.

Hi Tsuyoshi Ozawa, Test case failure is not related to this issue and seperate jira is already raised for it ( YARN-2871)

+1, committing this shortly. Hey Naganarasimha G R, could you open new JIRA to update documentation for this feature?

Committed this to trunk and branch-2. Thanks Naganarasimha G R for your contribution and thanks Varun Vasudev for your review!

SUCCESS: Integrated in Hadoop-trunk-Commit #7590 (See https://builds.apache.org/job/Hadoop-trunk-Commit/7590/)
YARN-3326. Support RESTful API for getLabelsToNodes. Contributed by Naganarasimha G R. (ozawa: rev e48cedc663b8a26fd62140c8e2907f9b4edd9785)

• hadoop-yarn-project/hadoop-yarn/hadoop-yarn-server/hadoop-yarn-server-resourcemanager/src/main/java/org/apache/hadoop/yarn/server/resourcemanager/webapp/dao/LabelsToNodesInfo.java
• hadoop-yarn-project/CHANGES.txt
• hadoop-yarn-project/hadoop-yarn/hadoop-yarn-server/hadoop-yarn-server-resourcemanager/src/main/java/org/apache/hadoop/yarn/server/resourcemanager/webapp/RMWebServices.java
• hadoop-yarn-project/hadoop-yarn/hadoop-yarn-server/hadoop-yarn-server-resourcemanager/src/test/java/org/apache/hadoop/yarn/server/resourcemanager/webapp/TestRMWebServicesNodeLabels.java
• hadoop-yarn-project/hadoop-yarn/hadoop-yarn-server/hadoop-yarn-server-resourcemanager/src/main/java/org/apache/hadoop/yarn/server/resourcemanager/webapp/NodeIDsInfo.java

Thanks Tsuyoshi Ozawa, thanks for the review, Will check the scope of yarn-2801 and if it doesnt cover this feature then will raise a new jira.

FAILURE: Integrated in Hadoop-Hdfs-trunk #2097 (See https://builds.apache.org/job/Hadoop-Hdfs-trunk/2097/)
YARN-3326. Support RESTful API for getLabelsToNodes. Contributed by Naganarasimha G R. (ozawa: rev e48cedc663b8a26fd62140c8e2907f9b4edd9785)

• hadoop-yarn-project/hadoop-yarn/hadoop-yarn-server/hadoop-yarn-server-resourcemanager/src/main/java/org/apache/hadoop/yarn/server/resourcemanager/webapp/NodeIDsInfo.java
• hadoop-yarn-project/hadoop-yarn/hadoop-yarn-server/hadoop-yarn-server-resourcemanager/src/test/java/org/apache/hadoop/yarn/server/resourcemanager/webapp/TestRMWebServicesNodeLabels.java
• hadoop-yarn-project/hadoop-yarn/hadoop-yarn-server/hadoop-yarn-server-resourcemanager/src/main/java/org/apache/hadoop/yarn/server/resourcemanager/webapp/dao/LabelsToNodesInfo.java
• hadoop-yarn-project/hadoop-yarn/hadoop-yarn-server/hadoop-yarn-server-resourcemanager/src/main/java/org/apache/hadoop/yarn/server/resourcemanager/webapp/RMWebServices.java
• hadoop-yarn-project/CHANGES.txt

FAILURE: Integrated in Hadoop-Hdfs-trunk-Java8 #156 (See https://builds.apache.org/job/Hadoop-Hdfs-trunk-Java8/156/)
YARN-3326. Support RESTful API for getLabelsToNodes. Contributed by Naganarasimha G R. (ozawa: rev e48cedc663b8a26fd62140c8e2907f9b4edd9785)

• hadoop-yarn-project/hadoop-yarn/hadoop-yarn-server/hadoop-yarn-server-resourcemanager/src/main/java/org/apache/hadoop/yarn/server/resourcemanager/webapp/RMWebServices.java
• hadoop-yarn-project/hadoop-yarn/hadoop-yarn-server/hadoop-yarn-server-resourcemanager/src/main/java/org/apache/hadoop/yarn/server/resourcemanager/webapp/NodeIDsInfo.java
• hadoop-yarn-project/CHANGES.txt
• hadoop-yarn-project/hadoop-yarn/hadoop-yarn-server/hadoop-yarn-server-resourcemanager/src/test/java/org/apache/hadoop/yarn/server/resourcemanager/webapp/TestRMWebServicesNodeLabels.java
• hadoop-yarn-project/hadoop-yarn/hadoop-yarn-server/hadoop-yarn-server-resourcemanager/src/main/java/org/apache/hadoop/yarn/server/resourcemanager/webapp/dao/LabelsToNodesInfo.java

FAILURE: Integrated in Hadoop-Yarn-trunk-Java8 #165 (See https://builds.apache.org/job/Hadoop-Yarn-trunk-Java8/165/)
YARN-3326. Support RESTful API for getLabelsToNodes. Contributed by Naganarasimha G R. (ozawa: rev e48cedc663b8a26fd62140c8e2907f9b4edd9785)

• hadoop-yarn-project/hadoop-yarn/hadoop-yarn-server/hadoop-yarn-server-resourcemanager/src/main/java/org/apache/hadoop/yarn/server/resourcemanager/webapp/RMWebServices.java
• hadoop-yarn-project/CHANGES.txt
• hadoop-yarn-project/hadoop-yarn/hadoop-yarn-server/hadoop-yarn-server-resourcemanager/src/main/java/org/apache/hadoop/yarn/server/resourcemanager/webapp/dao/LabelsToNodesInfo.java
• hadoop-yarn-project/hadoop-yarn/hadoop-yarn-server/hadoop-yarn-server-resourcemanager/src/test/java/org/apache/hadoop/yarn/server/resourcemanager/webapp/TestRMWebServicesNodeLabels.java
• hadoop-yarn-project/hadoop-yarn/hadoop-yarn-server/hadoop-yarn-server-resourcemanager/src/main/java/org/apache/hadoop/yarn/server/resourcemanager/webapp/NodeIDsInfo.java

FAILURE: Integrated in Hadoop-Yarn-trunk #899 (See https://builds.apache.org/job/Hadoop-Yarn-trunk/899/)
YARN-3326. Support RESTful API for getLabelsToNodes. Contributed by Naganarasimha G R. (ozawa: rev e48cedc663b8a26fd62140c8e2907f9b4edd9785)

• hadoop-yarn-project/hadoop-yarn/hadoop-yarn-server/hadoop-yarn-server-resourcemanager/src/main/java/org/apache/hadoop/yarn/server/resourcemanager/webapp/NodeIDsInfo.java
• hadoop-yarn-project/hadoop-yarn/hadoop-yarn-server/hadoop-yarn-server-resourcemanager/src/main/java/org/apache/hadoop/yarn/server/resourcemanager/webapp/dao/LabelsToNodesInfo.java
• hadoop-yarn-project/CHANGES.txt
• hadoop-yarn-project/hadoop-yarn/hadoop-yarn-server/hadoop-yarn-server-resourcemanager/src/main/java/org/apache/hadoop/yarn/server/resourcemanager/webapp/RMWebServices.java
• hadoop-yarn-project/hadoop-yarn/hadoop-yarn-server/hadoop-yarn-server-resourcemanager/src/test/java/org/apache/hadoop/yarn/server/resourcemanager/webapp/TestRMWebServicesNodeLabels.java

FAILURE: Integrated in Hadoop-Mapreduce-trunk-Java8 #166 (See https://builds.apache.org/job/Hadoop-Mapreduce-trunk-Java8/166/)
YARN-3326. Support RESTful API for getLabelsToNodes. Contributed by Naganarasimha G R. (ozawa: rev e48cedc663b8a26fd62140c8e2907f9b4edd9785)

• hadoop-yarn-project/CHANGES.txt
• hadoop-yarn-project/hadoop-yarn/hadoop-yarn-server/hadoop-yarn-server-resourcemanager/src/test/java/org/apache/hadoop/yarn/server/resourcemanager/webapp/TestRMWebServicesNodeLabels.java
• hadoop-yarn-project/hadoop-yarn/hadoop-yarn-server/hadoop-yarn-server-resourcemanager/src/main/java/org/apache/hadoop/yarn/server/resourcemanager/webapp/RMWebServices.java
• hadoop-yarn-project/hadoop-yarn/hadoop-yarn-server/hadoop-yarn-server-resourcemanager/src/main/java/org/apache/hadoop/yarn/server/resourcemanager/webapp/dao/LabelsToNodesInfo.java
• hadoop-yarn-project/hadoop-yarn/hadoop-yarn-server/hadoop-yarn-server-resourcemanager/src/main/java/org/apache/hadoop/yarn/server/resourcemanager/webapp/NodeIDsInfo.java

SUCCESS: Integrated in Hadoop-Mapreduce-trunk #2115 (See https://builds.apache.org/job/Hadoop-Mapreduce-trunk/2115/)
YARN-3326. Support RESTful API for getLabelsToNodes. Contributed by Naganarasimha G R. (ozawa: rev e48cedc663b8a26fd62140c8e2907f9b4edd9785)

• hadoop-yarn-project/hadoop-yarn/hadoop-yarn-server/hadoop-yarn-server-resourcemanager/src/main/java/org/apache/hadoop/yarn/server/resourcemanager/webapp/dao/LabelsToNodesInfo.java
• hadoop-yarn-project/hadoop-yarn/hadoop-yarn-server/hadoop-yarn-server-resourcemanager/src/test/java/org/apache/hadoop/yarn/server/resourcemanager/webapp/TestRMWebServicesNodeLabels.java
• hadoop-yarn-project/CHANGES.txt
• hadoop-yarn-project/hadoop-yarn/hadoop-yarn-server/hadoop-yarn-server-resourcemanager/src/main/java/org/apache/hadoop/yarn/server/resourcemanager/webapp/RMWebServices.java
• hadoop-yarn-project/hadoop-yarn/hadoop-yarn-server/hadoop-yarn-server-resourcemanager/src/main/java/org/apache/hadoop/yarn/server/resourcemanager/webapp/NodeIDsInfo.java