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
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.
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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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tcp_posix_test is incorrectly assuming that all endpoint_writes with
timestamps enabled will be successfully traced. Remove the timestamps
checking related tests to prevent flakes when the test is enabled
internally.
This adds a new channel argument `GRPC_ARG_DSCP` which allows users to
create classified gRPC streams with a
Differentiated Services Code Point (DSCP) marking on the IP frames.
The channel argument is handled on both clients and servers, but
currently only on posix based systems.
Fixes#17225
**Background**:
In addition to what is already described is #17225, when gRPC is used in
telco systems there is often a need to classify streams of importance.
There can be multiple hops between two endpoints (e.g. between 2 telecom
operators) and some streams that are more important than others (e.g.
emergency call related or similar). By marking the IP packets using DSCP
the aware routers can make a sound decision of the prioritization.
This PR propose to use DSCP as the configuration value since its common
for both IPv4/IPv6, an alternative would be to use a config name that
includes TOS and Traffic Class.
There might be more needed regarding documentation and end2end testing,
but there I need some advice.
**References**
https://datatracker.ietf.org/doc/html/rfc2474https://www.iana.org/assignments/dscp-registry/dscp-registry.xhtml
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@yashykt
Upgrade apple platform deployment_target versions to fix the cocoapods
push of BoringSSL-GRPC about the following error:
```
ld: file not found: /Applications/Xcode.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/lib/arc/libarclite_macosx.a
clang: error: linker command failed with exit code 1 (use -v to see invocation)
```
ref: https://developer.apple.com/forums/thread/725300
This also aligns with the versions required by
[protobuf](https://github.com/protocolbuffers/protobuf/pull/10652)
```
ios.deployment_target = '10.0'
osx.deployment_target = '10.12'
tvos.deployment_target = '12.0'
watchos.deployment_target = '6.0'
```
Notes:
- `+trace` fixtures haven't run since 2016, so they're disabled for now
(7ad2d0b463 (diff-780fce7267c34170c1d0ea15cc9f65a7f4b79fefe955d185c44e8b3251cf9e38R76))
- all current fixtures define `FEATURE_MASK_SUPPORTS_AUTHORITY_HEADER`
and hence `authority_not_supported` has not been run in years - deleted
- bad_hostname similarly hasn't been triggered in a long while, so
deleted
- load_reporting_hook has never been enabled, so deleted
(f23fb4cf31/test/core/end2end/generate_tests.bzl (L145-L148))
- filter_latency & filter_status_code rely on global variables and so
don't convert particularly cleanly - and their value seems marginal, so
deleted
---------
Co-authored-by: ctiller <ctiller@users.noreply.github.com>
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---------
Co-authored-by: ctiller <ctiller@users.noreply.github.com>
This is a big rewrite of global config.
It does a few things, all somewhat intertwined:
1. centralize the list of configuration we have to a yaml file that can
be parsed, and code generated from it
2. add an initialization and a reset stage so that config vars can be
centrally accessed very quickly without the need for caching them
3. makes the syntax more C++ like (less macros!)
4. (optionally) adds absl flags to the OSS build
This first round of changes is intended to keep the system where it is
without major changes. We pick up absl flags to match internal code and
remove one point of deviation - but importantly continue to read from
the environment variables. In doing so we don't force absl flags on our
customers - it's possible to configure grpc without the flags - but
instead allow users that do use absl flags to configure grpc using that
mechanism. Importantly this lets internal customers configure grpc the
same everywhere.
Future changes along this path will be two-fold:
1. Move documentation generation into the code generation step, so that
within the source of truth yaml file we can find all documentation and
data about a configuration knob - eliminating the chance of forgetting
to document something in all the right places.
2. Provide fuzzing over configurations. Currently most config variables
get stashed in static constants across the codebase. To fuzz over these
we'd need a way to reset those cached values between fuzzing rounds,
something that is terrifically difficult right now, but with these
changes should simply be a reset on `ConfigVars`.
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---------
Co-authored-by: ctiller <ctiller@users.noreply.github.com>
With iomgr, this test is effectively rate limited by ExecCtx and the
single thread running pollset_work, which results in thousands of tiny
writes happening before every read. A small set of _synchronous_ 8k
reads then dominate the read-side of the test. This is an efficient
balance.
With the Windows EventEngine, the fully asynchronous, multi-threaded
reads and writes end up alternating roughly 1:1, meaning that a read
callback is executed for every tiny handful of bytes, tens of thousands
of times. Compared to the Posix EventEngine, without things like TCP_INQ
and/or recvmsg's timeout, I don't know of any great signal for how much
data can safely be received in a batch (e.g., we don't want to wait for
data that will never come, and we don't want to run callbacks for 2
bytes over and over again if we have KB in the pipe).
I believe the Windows EventEngine is WAI. I can significantly improve
this test performance by artificially slowing the reader down (adding a
>= 1ms sleep), but I believe that improves this use case to the
detriment of all others.
* Revert "Revert "Add support for systemd socket activation (#30485)" (#31617)"
This reverts commit 867dc6cae2.
* Add checks to unix tests
* Ran generate_projects.sh and fixed styling in test
* Fix variable in unit test
* Use reinterpret_cast in test
* Rebase and fix sanity failures
Mark D. Roth