* Implement missing pieces for connection backoff.
Spec can be found here:
https://github.com/grpc/grpc/blob/master/doc/connection-backoff.md
Summary of changes:
* Added a new type (marked experimental), ConnectParams, which contains
the knobs defined in the spec (except for minConnectTimeout).
* Added a new API (marked experimental), WithConnectParams() to return a
DialOption to dial with the provided parameters.
* Added new fields to the implementation of the exponential backoff in
internal/backoff which mirror the ones in ConnectParams.
* Marked existing APIs WithBackoffMaxDelay() and WithBackoffConfig() as
deprecated.
* Added a default exponential backoff implementation, for easy use of
internal callers.
Added a new backoff package which defines the backoff configuration
options, and is used by both the grpc package and the internal/backoff
package. This allows us to have all backoff related options in a
separate package.
Also, deprecate WithBalancerName (was experimental).
The decision of whether something may be removed is based on if it was marked experimental as of v1.0/GA or upon its introduction, in accordance with Documentation/versioning.md.
* internal: fix Dial_OneBackoffPerRetryGroup
Instead of mutating global variables, switches getMinConnectDeadline to a
dial option.
Fixes#2687.
* rename getMinConnectTimeoutFunc to minConnectTimeout, ditto dial opt
Possible settings of this environment variable:
- "hybrid" (default; removed after the 1.17 release): do not wait for handshake before considering a connection ready, but wait before considering successful.
- "on" (default after the 1.17 release): wait for handshake before considering a connection ready/successful.
- "off": do not wait for handshake before considering a connection ready/successful.
This setting will be completely removed after the 1.18 release, and "on" will be the only supported behavior.
Google default creds is a combo of ALTS, TLS and OAuth2. The right set of creds will be picked to use based on environment.
This PR contains:
- A new `creds.Bundle` type
- changes to use it in ClientConn and transport
- dial option to set the bundle for a ClientConn
- balancer options and NewSubConnOption to set it for SubConn
- Google default creds implementation by @cesarghali
- grpclb changes to use different creds mode for different servers
- interop client changes for google default creds testing
Stefan Sauer
Doug Fawley
Easwar Swaminathan
Jean de Klerk
Weiran Fang
lyuxuan
Menghan Li
Dustin Spicuzza