nearest-neighbor-search

Is there an existing issue for this?

• I have searched the existing issues

What would you like to be added?

When a user reports a bug in an issue, in addition to "Environment", "Current Behavior", "Expected Behavior", and "Steps To Reproduce", a "Milvus log" needs to be added to the issue template.

![image](https://user-images.githubusercontent.com/53512883/162382819-86855bd6-7f6

Hi,

There are still parts of boost library that are used inside mlpack, more specifically in here

• mlpack/src/mlpack/core/tree/cosine_tree/cosine_tree.hpp boost::heap
• mlpack/src/mlpack/core/data/load_arff.hpp boost::tokenizer
• mlpack/tests/main_tests/emst_test.cpp boost::math::iround()
• mlpack/core/tree/cosine_tree/cosine_tree.cpp boost::m

Is your feature request related to a problem? Please describe.
There are cases, when it might be useful to know how much points are there in index, which satisfies some filtering condition.
Currently, we can only estimate a total amount of points.

Describe the solution you'd like
Create an API which returns amount of points (estimated or precise, depending on flag) for a given filter

https://arxiv.org/abs/2006.09882

N2 does not have code formatting check process before pushing the code.
We need to add the process.

e.g coala

Current docker image size is insane. It is 2.55 GB. Reduce that to below 1GB or less. Apply changes from this reference: https://hackernoon.com/tips-to-reduce-docker-image-sizes-876095da3b34

Describe the bug

Elastiknn exceptions do not extend ElasticsearchException, so they seem to always be turned into a 500, when a 4xx would often be more appropriate.

Expected behavior

• When a query is incompatible with a mapping, use an exception that will get converted to a 400 response code. [See code where exception is initialized.](https://github.com/alexklibisz/elastiknn/blob