Connection doesn't automatically close

[Sven65]

Using the connection pool in an app that pulls data from a RDB server based on user activity doesn't work as intented.

The library inflates the connection pool to the extremes making the application crash due to a TCP Read error by never closing the connection after the query has been ran.

[mxstbr]

This is biting us in the butt really hard right now in production, has anybody found a workaround?

[mxstbr]

This code is very suspicious:

rethinkdbdash/lib/pool.js

Lines 159 to 169 in 7421553

	/*
	// We let the pool garbage collect these connections
	else if (self.getAvailableLength()+1 > self.options.buffer) { // +1 for the connection we may put back
	// Note that because we have available connections here, the pool master has no pending
	// queries.
	connection.close().error(function(error) {
	self._log('Fail to properly close a connection. Error:'+JSON.stringify(error));
	});
	clearTimeout(connection.timeout);
	}
	*/

Maybe that's the culprit?

[benfletcher]

FWIW, Spectrum.chat forked rethinkdbdash for the apparent sole purpose of uncommenting that code:

withspectrum/spectrum@245aeae

The source for the fork is not on Github and only on npm. Doing a diff, the only other difference I saw was the addition of an .npmignore file and resulting absence of node_modules in the package.

The forked package is rethinkhaberdashery.

[mxstbr]

That is correct, that was us! 👍 Feel free to use the package, but it is unlikely we will do any more maintenance on it.

The real fix in our case was to limit the number of connections much lower than the defaults and making the buffer and max connections the same amount to avoid constantly opening and closing connections. We also talked with our DB hosting provider (compose.io) to make sure we were not exceeding the max amount of connections their proxy could handle (2000).

https://github.com/withspectrum/spectrum/blob/alpha/shared/db/db.js#L12-L19