Jackpot is a fault tolerant connection pool for Node.js, it automatically cleans up after it self and detects broken connections. It does not need to be released, as it will allocate connections based on their readyState / write abilities.
var ConnectionPool = require('jackpot');
// First argument: size of the connection pool.
// Second argument: optional connection factory.
// Third argument: optional options.
var pool = new ConnectionPool(100);
The following options can be configured:
retries
the amount of retries the pull method should do.factor
exponential backoff factor.min
minimal delay for the backoff.max
maximum delay for the backoff.randomize
randomize the connection.
var pool = new ConnectionPool(100, {
min: 100
max: 50000
});
But you can also set the properties:
// you can optionally boost the amount of retries after you have
// constructed a new instance
pool.retries = 5 // allow 5 failures for the #pull method
You can set the required factory at the contructor but also through a helper method:
// every connection pool requires a factory which is used to generate / setup
// the initial net.Connection
//
// it should return a new net.Connection instance..
pool.factory(function () {
return net.connect(port, host)
});
There are 2 ways to retrieve a connection, using allocate
:
``js` // now that the pool is setup we can allocate a connection, the allocate // requires a callback as it can be async.. pool.allocate(function (err, connection) { // error: when we failed to get a connection // connection: the allocated net.connection if there isn't an error });
And `pull`;
```js
// in addition to the #allocate method, there is also the pull method, which is
// fault tolerant wrapper around the allocate function as it can give back an
// error if the pool is full, so the pull will then retry to get a new
connection.pull(function (err, connection) {
// same arguments as the #allocate method
});
And some misc methods:
// call pool.free if you want to free connections from the pool, the arugment
// you supply is the amount of connections you want to keep
pool.free(10); // keep only 10 healthy connections kill the rest.
// kill the whole connection pool:
pool.end();
For more API information, fork this repo and add more.. or look at the test file.
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