private HostPortPoolManager getHostPortPoolManager(String host, Port port, DataNodeId dataNodeId) {
    return hostPortToPoolManager.computeIfAbsent(new Pair<>(host, port), k -> new HostPortPoolManager(host, port,
        port.getPortType() == PortType.SSL ? maxConnectionsPerPortSsl : maxConnectionsPerPortPlainText, dataNodeId));
  }
Returns the {@link HostPortPoolManager} associated with the (host, port) pair. Creates one if not available
already.
@param host The hostname
@param port The port
@param dataNodeId The {@link DataNodeId} associated with (host, port) pair
@return the HostPortPoolManager for the associated (host, port) pair.
ambry-network/src/main/java/com/github/ambry/network/ConnectionTracker.java