This allows the initial RPC(s) an opportunity to apply settings from the service config; without this change we would still block, but only after observing the current service config settings.
In very rare cases, we could start an RPC before the picker had been updated to
one that would return a valid SubConn. This is not a problem as the new picker
will be called again as soon as it is updated, but it can lead to test flakes
that depend upon the picker not being called before being ready.
Also includes:
- Export `NewLoggerFromConfigString` so it can be also used when config string is specified in another way (e.g. command line flag)
- Export `Logger` so user can install custom sink
- Add temp file sink implementation
- Take advantage of `grep`'s status code, where possible
- Make the appengine check in vet.go exit with non-zero status if an error is encountered
- Add "fail_on_output" for the `tee|read` that we do when the status code cannot be used, to make it clear what it's for
- Document all our various checks
internal: fix GO_AWAY deadlock
A deadlock can occur when a GO_AWAY is followed by a connection closure. This
happens because onClose needlessly closes the current ac.transport: if a
GO_AWAY already occured, and the transport was already reset, then the later
closure (of the original address) sets ac.transport - which is now healthy -
to nil.
The manifestation of this problem is that picker_wrapper spins forever trying
to use a READY connection whose ac.transport is nil.
Method logger will be picked by each RPC at the beginning to log binary entries. It also handles truncating.
This PR also adds script to download proto from grpc/grpc-proto
internal: fix client send preface problems
This CL fixes three problems:
- In clientconn_state_transitions_test.go, sometimes tests would flake because there's not enough buffer to send client side settings, causing the connection to unpredictably enter TRANSIENT FAILURE. Each time we set up a server to send SETTINGS, we should also set up the server to read. This allows the client to successfully send its SETTINGS, unflaking the test.
- In clientconn.go, we incorrectly transitioned into TRANSIENT FAILURE when creating an http2client returned an error. This should be handled in the outer resetTransport main reset loop. The reason this became a problem is that the outer resetTransport has very specific conditions around when to transition into TRANSIENT FAILURE that the egregious transition did not have. So, it could transition into TRANSIENT FAILURE after failing to dial, even if it was trying to connect to a non-final address in the list of addresses.
- In clientconn.go, we incorrectly stay in CONNECTING after `createTransport` when a server sends its connection preface but the client is not able to send its connection preface. This CL causes the addrconn to correctly enter TRANSIENT FAILURE when `createTransport` fails, even if a server preface was received. It does so by making ac.successfulHandshake to consider both server preface received as well as client preface sent.
internal: clean up and unflake state transitions test
Switches state transitions test to using a notification from a custom load
balancer, instead of relying on waiting for laggy balancer state updates.
Also generally adds more coverage around state transitions and a framework
for easily adding more of these kinds of tests.
Fixes#2348
lyuxuan