Keeper bench 2.0

[antonio2368]

Changelog category (leave one):

• Build/Testing/Packaging Improvement

Changelog entry (a user-readable short description of the changes that goes to CHANGELOG.md):

New and improved keeper-bench.
Everything can be customized from yaml/XML file:

• request generator
  • each type of request generator can have a specific set of fields
  • multi requests can be generated just by doing the same under multi key
  • for each request or subrequest in multi a weight field can be defined to control distribution
• define trees that need to be setup for a test run
• hosts can be defined with all timeouts customizable and it's possible to control how many sessions to generate for each host
• integers defined with min_value and max_value fields are random number generators

There is an example of a configuration in utils/keeper-bench/example.yaml.

Things left to do:

• how to generate results?
• what data to collect (throughput, latency...)
• Update README with everything explained

cc @alesapin @qoega

Documentation entry for user-facing changes

• Documentation is written (mandatory for new features)

Information about CI checks: https://clickhouse.com/docs/en/development/continuous-integration/

[pufit]

This commit broke for me the build on MacOS with -DENABLE_LIBRARIES=0 :(

CMake Error at utils/keeper-bench/CMakeLists.txt:2 (target_link_libraries):
  Target "keeper-bench" links to:

    ch_contrib::rapidjson

  but the target was not found.  Possible reasons include:

    * There is a typo in the target name.
    * A find_package call is missing for an IMPORTED target.
    * An ALIAS target is missing.