Resource not currently part of this pool

[189]

I make 20 request after create connection pool with 10 max connection, but always got “Resource not currently part of this pool”。Here is my all code:

const genericPool = require("generic-pool");

const factory = {
  create: function () {
    console.log("factory create");
    return null;
  },
  destroy: function () {
    console.log("====> factory destroy");
    return true;
  }
};

const pool = genericPool.createPool(factory, {
  max: 10, // maximum size of the pool
  idleTimeoutMillis: 30000,
  min: 2
});

function fetch(idx) {
  return new Promise((resolve) => {
    setTimeout(() => {
      console.log(idx, "done");
      resolve();
    }, 1 * 1000);
  });
}

let n = 0;

while (n < 20) {
  ((m) => {
    pool
      .acquire()
      .then((client) => {
        return fetch(m).then(() => {
          console.log(m, "release");
          return pool.release(client);
        });
      })
      .catch(function (err) {
        console.log("err=>", err);
      });
  })(n);
  n++;
}

pool.drain().then(function () {
  pool.clear();
});

"generic-pool": "^3.8.2"

Here is online demo

[eliellis]

Works fine for me if the pool create function returns something other than null, like an empty object. See here. The implementation compares unique instances internally, and null is not a unique instance when calling release, which is which is why you are seeing this error.