[HDFS-12005] Ozone: Web interface for SCM

• Type: Sub-task
• Status: Resolved
• Priority: Major
• Resolution: Fixed
• Affects Version/s: HDFS-7240
• Component/s: ozone
• Target Version/s: HDFS-7240
• Hadoop Flags: Reviewed
• Assignee: Marton Elek
• Reporter: Marton Elek
• Created: 20/Jun/17 23:04
• Updated: 26/Apr/18 21:53
• Resolved: 15/Aug/17 00:21

Description

This is a propsal about how a web interface could be implemented for SCM (and later for KSM) similar to the namenode ui.

1. JS framework

There are three big option here.

A.) One is to use a full featured web framework with all the webpack/npm minify/uglify magic. Build time the webpack/npm scripts should be run and the result will be added to the jar file.

B.) It could be simplified if the generated minified/uglified js files are added to the project on commit time. It requires an additional step for every new patch (to generate the new minified javascripts) but doesn't require additional JS build tools during the build.

C.) The third option is to make it as simple as possible similar to the current namenode ui which uses javascript but every dependency is commited (without JS minify/uglify and other preprocessing).

I prefer to the third one as:

• I have seen a lot of problems during frequent builds od older tez-ui versions (bower version mismatch, npm version mismatch, npm transitive dependency problems, proxy problem with older versions). All they could be fixed but requires additional JS/NPM magic/knowledge. Without additional npm build step the hdfs projects build could be kept more simple.

• The complexity of the planned SCM/KSM ui (hopefully it will remain simple) doesn't require more sophisticated model. (Eg. we don't need JS require as we need only a few controllers)

• HDFS developers mostly backend developers and not JS developers

2. Frameworks

The big advantages of a more modern JS framework is the simplified programming model (for example with two way databinding) I suggest to use a more modern framework (not just jquery) which supports plain js (not just ECMA2015/2016/typescript) and just include the required js files in the projects (similar to the included bootstrap or as the existing namenode ui works).

• React could be a good candidate but it requires more library as it's just a ui framework, even the REST calls need separated library. It could be used with plain javascript instead of JSX and classes but not straightforward, and it's more verbose.

• Ember is used in yarnui2 but the main strength of the ember is the CLI which couldn't be used for the simplified approach easily. I think ember is best with the A.) option

• Angular 1 is a good candidate (but not so fancy). In case of angular 1 the component based approach should be used (in that case later it could be easier to migrate to angular 2 or react)

• The mainstream side of Angular 2 uses typescript, it could work with plain JS but it could require additional knowledge, most of the tutorials and documentation shows the typescript approach.

I suggest to use angular 1 or react. Maybe angular is easier to use as don't need to emulate JSX with function calls, simple HTML templates could be used.

3. Backend

I would prefer the approach of the existing namenode ui where the backend is just the jmx endpoint. To keep it as simple as possible I suggest to try to avoid dedicated REST backend if possible. Later we can use REST api of SCM/KSM if they will be implemented.

Issue Links

• is cloned by: HDFS-12034 Ozone: Web interface for KSM