This new directory combines code from the following locations:
- src/core/ext/filters/client_channel/resolver
- src/core/lib/resolver
Closes#35804
COPYBARA_INTEGRATE_REVIEW=https://github.com/grpc/grpc/pull/35804 from markdroth:client_channel_resolver_reorg2 30660e6b00
PiperOrigin-RevId: 604665835
This new directory combines code from the following locations:
- src/core/ext/filters/client_channel/lb_policy
- src/core/lib/load_balancing
Closes#35786
COPYBARA_INTEGRATE_REVIEW=https://github.com/grpc/grpc/pull/35786 from markdroth:client_channel_resolver_reorg 98554efb98
PiperOrigin-RevId: 604351832
More changes as part of the dualstack design:
- Change resolver and LB policy APIs to support multiple addresses per
endpoint. Specifically, replace `ServerAddress` with
`EndpointAddresses`, which encodes more than one address. Per-address
channel args are retained at the same level, so they are now
per-endpoint. For now, `EndpointAddress` provides a single-address ctor
and a single-address accessor for backward compatibility, so
`ServerAdress` is an alias for `EndpointAddresses`; eventually, this
alias and the single-address methods will be removed.
- Add an `EndpointAddressSet` class, which represents an unordered set
of addresses to be used as a map key. This will be used in a number of
LB policies that need to store per-endpoint state.
- Change the LB policy API's `ChannelControlHelper::CreateSubchannel()`
method to take the address and per-endpoint channel args as separate
parameters, so that we don't need to construct a legacy `ServerAddress`
object as we create a new subchannel for each address in the endpoint.
- Change pick_first to flatten the address list.
- Change ring_hash to use `EndpointAddressSet` as the key for its
endpoint map, and to use the first address of the endpoint as the hash
key.
- Change WRR to use `EndpointAddressSet` as the key for its endpoint
weight map.
Note that support for multiple addresses per endpoint is guarded in RR
by the existing `round_robin_delegate_to_pick_fist` experiment and in
WRR by the existing `wrr_delegate_to_pick_first` experiment.
This PR does *not* include support for multiple addresses per endpoint
for the outlier_detection or xds_override_host LB policies; those will
come in subsequent PRs.
Rolls forward https://github.com/grpc/grpc/pull/33871
Second and third commits here fix internal build issues
In particular, add a `// IWYU pragma: no_include <ares_build.h>` since
`ares.h` [includes that
anyways](bad62225b7/include/ares.h (L23))
(and seems unlikely for that to change since it would be breaking)
Normally, c-ares related fds are destroyed after all DNS resolution is
finished in [this code
path](c82d31677a/src/core/ext/filters/client_channel/resolver/dns/c_ares/grpc_ares_wrapper.cc (L210)).
Also there are some fds that c-ares may fail to open or write to
initially, and c-ares will close them internally before grpc ever knows
about them.
But if:
1) c-ares opens a socket and successfully writes a request on it
2) then a subsequent read fails
Then c-ares will close the fd in [this code
path](bad62225b7/src/lib/ares_process.c (L740)),
but gRPC will have a reference on the fd and will still use it
afterwards.
Fix here is to leverage the c-ares socket-override API to properly track
fd ownership between c-ares and grpc.
Related: internal issue b/292203138
This PR implements a c-ares based DNS resolver for EventEngine with the
reference from the original
[grpc_ares_wrapper.h](../blob/master/src/core/ext/filters/client_channel/resolver/dns/c_ares/grpc_ares_wrapper.h).
The PosixEventEngine DNSResolver is implemented on top of that. Tests
which use the client channel resolver API
([resolver.h](../blob/master/src/core/lib/resolver/resolver.h#L54)) are
ported, namely the
[resolver_component_test.cc](../blob/master/test/cpp/naming/resolver_component_test.cc)
and the
[cancel_ares_query_test.cc](../blob/master/test/cpp/naming/cancel_ares_query_test.cc).
The WindowsEventEngine DNSResolver will use the same EventEngine's
grpc_ares_wrapper and will be worked on next.
The
[resolve_address_test.cc](https://github.com/grpc/grpc/blob/master/test/core/iomgr/resolve_address_test.cc)
which uses the iomgr
[DNSResolver](../blob/master/src/core/lib/iomgr/resolve_address.h#L44)
API has been ported to EventEngine's dns_test.cc. That leaves only 2
tests which use iomgr's API, notably the
[dns_resolver_cooldown_test.cc](../blob/master/test/core/client_channel/resolvers/dns_resolver_cooldown_test.cc)
and the
[goaway_server_test.cc](../blob/master/test/core/end2end/goaway_server_test.cc)
which probably need to be restructured to use EventEngine DNSResolver
(for one thing they override the original grpc_ares_wrapper's free
functions). I will try to tackle these in the next step.
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This PR also centralizes the client channel resolver selection. Resolver
selection is still done using the plugin system, but when the Ares and
native client channel resolvers go away, we can consider bootstrapping
this differently.
* Support unix socket in grpc_sockaddr_to_string
* make it return statusor
* clang fix
* made grpc_sockaddr_to_string() to return statusor
* Let Chttp2ServerListener::Start crash
* test failure fixed
* api_fuzzer fixed
* comments addressed.
* more comments addressed
* comments addressed
* fix other broken builds
* Refactor end2end tests to exercise each EventEngine
* fix incorrect bazel_only exclusions
* Automated change: Fix sanity tests
* microbenchmark fix
* sanitize, fix iOS flub
* Automated change: Fix sanity tests
* iOS fix
* reviewer feedback
* first pass at excluding EventEngine test expansion
Also caught a few cases where we should not test pollers, but should
test all engines. And two cases where we likely shouldn't be testing
either product.
* end2end fuzzers to be fuzzed differently via EventEngine.
* sanitize
* reviewer feedback
* remove misleading comment
* reviewer feedback: comments
* EE test_init needs to play with our build system
* fix golden file test runner
Co-authored-by: drfloob <drfloob@users.noreply.github.com>
This replaces gflags. Added TODOs where use of `absl::Duration` or `absl::FlagSaver` might be preferred in follow-up cleanup. Fixes#24493.
This reverts commit da66b7d14e.
NEW:
* Adds references to `absl/flags/declare.h`, new to LTS 2020923.2 imported in commit 5b43440.
* Works around MSVC 2017 compiler error with large help text on flags by reducing the help text.
Craig Tiller