HDDS-7612. Add documentation for container balancer

[david1859168]

What changes were proposed in this pull request?

Added the content about "Container balancer" under the "feature" menu from "https://docs.cloudera.com/cdp-private-cloud-base/7.1.8/ozone-storing-data/topics/ozone-container-balancer-cli.html"

What is the link to the Apache JIRA

https://issues.apache.org/jira/browse/HDDS-7612

[Galsza]

Thank you for working on this @david1859168 . Right now the documentation is also missing an overall description about what the container balancer feature is. I'd prefer if you could also add information on it. It could be also taken from container balancer overview

[david1859168]

Hi @Galsza I have added the container balancer overview, please review.

[Galsza]

@david1859168 Hi, thank you for updating the documentation. Official Apache documentation shouldn't reference Cloudera or Cloudera specific items so please remove those.

[david1859168]

Thank you @Galsza. I have modified and deleted the CM-related documents, please verify. deleted: ContainerBalancer-cfg.md deleted: ContainerBalancer-cm.md modified: ContainerBalancerOverview.md deleted: ozone-container-balancer1.png deleted: ozone-container-balancer2.png

[Galsza]

@david1859168 thank you for you update, LGTM +1

@errose28 could you please take a look at this?

[adoroszlai]

1. Please use hugo serve from the ozone/hadoop-hdds/docs to see what the generated documentation looks like.

Ozone build installs Hugo if not foud locally, so you can also use:

mvn -pl :hdds-docs clean package
open hadoop-hdds/docs/target/classes/docs/index.html

Afterwards, Hugo can be found at .dev-tools/hugo/bin/hugo

[david1859168]

@david1859168 we can't commit this in its current state. Thereare numerous problems that must be addressed:

1. The resulting format is not as expected. Please use hugo serve from the ozone/hadoop-hdds/docs to see what the generated documentation looks like.
2. Wording cannot be copied directly from other sources. Please explain the container balancer in your own words.
3. Content is overall lacking. We need more explanation of what the container balancer is, how it works, what CLIs are available and when to use them. For example, there are numerous configurations about what constitutes "unbalanced" and how much data to move on each iteration.

@siddhantsangwan can you help @david1859168 make more thorough docs for the balancer? It seems documentation updates were missed as part of that feature.

Hi @siddhantsangwan, there are a few pdf and Google docs available at https://issues.apache.org/jira/browse/HDDS-4656. Which one do you think should be put here?

[adoroszlai]

@siddhantsangwan can you please revisit this?

[adoroszlai]

Thanks @david1859168 for the contribution. We will need to revisit this.