Added option to turn on UDP for TPU transaction and make UDP based TPU off by default

[lijunwangs]

Problem

Introduce a way to turn down UDP based TPU off by default and an option to turn on it.

Summary of Changes

--tpu-enable-udp is introduced. And when this is on, the transaction receive and transaction forward is enabled using udp.

Except for a few tests which was hard-coded sending transactions using udp, most tests are being done with udp based tpu disabled.

Fixes #

[lijunwangs]

Investigating local_cluster test failure with udp disabled.

[pgarg66]

It's passing DEFAULT_TPU_ENABLE_UDP at most places where TestValidator is being initialized. There are only a few tests that are passing true (e.g. test_rpc_subscriptions). So, instead of passing the flag, can we just use it directly inside TestValidator constructor functions. Maybe define a new constructor that enables the UDP for the test cases that really need UDP. It'll remove the code change from a lot of files, and also remove the Cargo dependency on tpu-client

[lijunwangs]

It's passing DEFAULT_TPU_ENABLE_UDP at most places where TestValidator is being initialized. There are only a few tests that are passing true (e.g. test_rpc_subscriptions). So, instead of passing the flag, can we just use it directly inside TestValidator constructor functions. Maybe define a new constructor that enables the UDP for the test cases that really need UDP. It'll remove the code change from a lot of files, and also remove the Cargo dependency on tpu-client

Good idea. Let me look into it

[pgarg66]

It's passing DEFAULT_TPU_ENABLE_UDP at most places where TestValidator is being initialized. There are only a few tests that are passing true (e.g. test_rpc_subscriptions). So, instead of passing the flag, can we just use it directly inside TestValidator constructor functions. Maybe define a new constructor that enables the UDP for the test cases that really need UDP. It'll remove the code change from a lot of files, and also remove the Cargo dependency on tpu-client

Good idea. Let me look into it

Thanks for addressing it. I had another minor nit. Please see if it makes sense.

You can add the flag (tpu_enable_udp) to TestValidatorGenesis and default it to DEFAULT_TPU_ENABLE_UDP (and, set it to true in with_no_fees_udp()). Pass the flag to TestValidator::start() in start_with_mint_address() reading from self.

This will reduce the changes in test-validator and some of the tests.

[lijunwangs]

It's passing DEFAULT_TPU_ENABLE_UDP at most places where TestValidator is being initialized. There are only a few tests that are passing true (e.g. test_rpc_subscriptions). So, instead of passing the flag, can we just use it directly inside TestValidator constructor functions. Maybe define a new constructor that enables the UDP for the test cases that really need UDP. It'll remove the code change from a lot of files, and also remove the Cargo dependency on tpu-client

Good idea. Let me look into it

Thanks for addressing it. I had another minor nit. Please see if it makes sense.

You can add the flag (tpu_enable_udp) to TestValidatorGenesis and default it to DEFAULT_TPU_ENABLE_UDP (and, set it to true in with_no_fees_udp()). Pass the flag to TestValidator::start() in start_with_mint_address() reading from self.

This will reduce the changes in test-validator and some of the tests.

Done

[pgarg66]

LGTM