fix: perf issue, do not load proto on each search() call

[maksspace]

Issue

I wanted to use this client for a project, but the problem is it's extremely slow because it loads proto on each search() call which takes around 40ms just to load proto.

Here's a benchmark, it's a simple nodejs server that uses milvus client to search:

const http = require('http');
const { query } = require('./db-client');

const server = http.createServer();

function vector(dim) {
  const arr = new Array(dim);
  for (let i = 0; i < dim; i++) {
    arr[i] = Math.random();
  }
  return arr;
}

const vectors = {};

for (let dims = 128; dims <= 2048; dims += 128) {
  vectors[dims] = vector(dims);
}

server.on('request', (request, res) => {
  const dims = +request.url.slice(1);
  
  query('milvus', `random_${dims}`, vectors[dims]).then((d) => {
     return res.end('Ok.');
  }).catch((e) => {
    console.log(e);
    res.writeHead(500);
    return res.end('Bad.')
  });
});

server.listen(8000);

Dataset

id as varchar 24, and float vector with 128 dimensions, 500K vectors.

Env:

CPU AMD Ryzen 3900X
32GB ram DDR4
SSD 512GB WD black PCIe 4.0 m2

Results

I think it's speaks for itself :)

[sre-ci-robot]

Welcome @maksspace! It looks like this is your first PR to milvus-io/milvus-sdk-node 🎉

[shanghaikid]

/lgtm

[shanghaikid]

/approve

[sre-ci-robot]

[APPROVALNOTIFIER] This PR is NOT APPROVED

This pull-request has been approved by: maksspace, shanghaikid

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[shanghaikid]

Thanks a lot.