[471] - Close underlying HTTP Client on closing Connection

[Varun0157]

(Addresses #471).

What type of PR is this?

• Bug Fix

Description

Currently, on session closure, the thrift backend invokes self._transport.close() which simply releases a connection back to the underlying pool. It does not close the pool itself. This leads to the TCP connection not being closed properly and a dangling CLOSE_WAIT state as pointed out in the above issue.

Thus, we rename _transport.close() to the more appropriate _transport.release_connection() and implement a new _transport.close() that actually closes the underlying pool.

We invoke this method on SEA backend session closure as well.

How is this tested?

• Unit tests
• E2E Tests
• Manually - using the same scripts mentioned in the description of TCP connection not closing properly leading to dangling CLOSE_WAIT state and system overload #471 - the connection is now closed properly and there is no dangling CLOSE_WAIT.
• N/A

Related Tickets & Documents

#471