Splitting off from https://github.com/grpc/grpc/pull/34273
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In certain situations the current flow control algorithm can result in
sending one flow control update write for every write sent (known
situation: rollout of promise based server calls with qps_test).
Fix things up so that the updates are only sent when truly needed, and
then fix the fallout (turns out our fuzzer had some bugs)
I've placed actual logic changes behind an experiment so that it can be
incrementally & safely rolled out.
This should address one of the failures we're seeing in #34224.
The test failure is caused by the changes in timing triggering a race
condition. In the code at head, we delay sending out the subscription
for the first CDS watch until we've already seen the other two CDS
watches, because the previous send_message op has not yet completed, and
by the time it does, we've seen all 3 watches, so we can send a
subscription for all 3 at the same time. With the WorkSerializer change,
the send_message op is complete by the time we see the first CDS watch,
so we subscribe to only that resource, and then later add the other two.
The result is that we'll NACK twice with two different messages, the
first one including only the error about the first resource, and the
second one including all three.
I suspect this same race condition would have been triggered eventually
by the EventEngine migration anyway; the current test basically depends
on the single-thread timing of the iomgr approach. So I'm addressing it
by replacing the e2e test with a unit test that covers the same cases
without the timing issue.
Rolls forward part of the dualstack changes, mostly from #33427 and a
little bit from #32692, both of which were reverted in #33718.
Specifically:
- For petiole policies, unconditionally start health watch on
subchannels, even if client side health checking is not enabled; in this
case, the health watch will report the subchannel's raw connectivity
state.
- Fix edge cases in health check reporting that occur when a watcher is
started before the initial state is reported.
- When client-side health checking fails, add the subchannel's address
to the RPC failure status message.
- Outlier detection now works only via the health checking watch, not
via the raw connectivity state watch.
- Remove now-unnecessary hack to ensure that outlier detection does not
work for pick_first.
This rolls forward only the pick_first changes from #32692, which were
rolled back in #33718. Specifically:
- Changes PF to use its own subchannel list implementation instead of
using the subchannel_list library, since the latter will be going away
with the dualstack changes.
- As a result of no longer using the subchannel_list library, PF no
longer needs to set the `GRPC_ARG_INHIBIT_HEALTH_CHECKING` channel arg.
- Adds an option to start a health watch on the chosen subchannel, to be
used in the future when pick_first is the child of a petiole policy.
(Currently, this code is not actually called anywhere.)
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---------
Co-authored-by: Mark D. Roth <roth@google.com>
Co-authored-by: markdroth <markdroth@users.noreply.github.com>
Co-authored-by: ctiller <ctiller@users.noreply.github.com>
Pipe-like type (has a send end, a receive end, and a closing mechanism)
for cross-activity transfers.
---------
Co-authored-by: ctiller <ctiller@users.noreply.github.com>
If we get a readable event on an fd and both the following happens:
- c-ares does *not* read all bytes off the fd
- c-ares removes the fd from the set ARES_GETSOCK_READABLE
... then we have a busy loop here, where we'd keep asking c-ares to
process an fd that it no longer cares about.
This is indirectly related to a change in this code one month ago:
https://github.com/grpc/grpc/pull/33942 - before that change, c-ares
would close the socket when it called
[handle_error](7f3262312f/src/lib/ares_process.c (L707))
and so `IsFdStillReadableLocked` would start returning `false`, causing
us to get away with [this
loop](f6a994229e/src/core/ext/filters/client_channel/resolver/dns/c_ares/grpc_ares_wrapper.cc (L371)).
Now, because `IsFdStillReadableLocked` will keep returning true (because
of our overridden `close` API), we'll loop forever.
Building out a new framing layer for chttp2.
The central idea here is to have the framing layer be solely responsible
for serialization of frames, and their deserialization - the framing
layer can reject frames that have invalid syntax - but the enacting of
what that frame means is left to a higher layer.
This class will become foundational for the promise conversion of chttp2
- by eliminating action from the parsing of frames we can reuse this
sensitive code.
Right now the new layer is inactive - there's a test that exercises it
relatively well, and not much more. In the next PRs I'll add an
experiments to enable using this layer or the existing code in the
writing and reading paths.
---------
Co-authored-by: ctiller <ctiller@users.noreply.github.com>
This is the initial implementation of the chaotic-good client transport
write path. There will be a follow-up PR to fulfill the read path.
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We enabled OpenSSL3 testing with #31256 and missed a failing test
It wasn't running before, so this isn't a regression - disabling it so
master doesn't fail while we figure out how to fix it.
Update from gtcooke94:
This PR adds support to build gRPC and it's tests with OpenSSL3. There were some
hiccups with tests as the tests with openssl haven't been built or exercised in a
few months, so they needed some work to fix.
Right now I expect all test files to pass except the following:
- h2_ssl_cert_test
- ssl_transport_security_utils_test
I confirmed locally that these tests fail with OpenSSL 1.1.1 as well,
thus we are at least not introducing regressions. Thus, I've added compiler directives around these tests so they only build when using BoringSSL.
---------
Co-authored-by: Gregory Cooke <gregorycooke@google.com>
Co-authored-by: Esun Kim <veblush@google.com>
- add debug-only `WorkSerializer::IsRunningInWorkSerializer()` method
and use it in client_channel to verify that subchannels are destroyed in
the `WorkSerializer`
- note: this mechanism uses `std:🧵:id`, so I had to exclude
work_serializer.cc from the core_banned_constructs check
- fix `WorkSerializer::Run()` to unref the callback before releasing
ownership of the `WorkSerializer`, so that any refs captured by the
`std::function<>` will be released before releasing ownership
- fix the WRR timer callback to hop into the `WorkSerializer` to release
its ref to the picker, since that transitively releases refs to
subchannels
- fix subchannel connectivity state notifications to unref the watcher
inside the `WorkSerializer`, since the watcher often transitively holds
refs to subchannels
Proposed alternative to https://github.com/grpc/grpc/pull/34024.
This version has a simpler, faster busy-count implementation based on a
sharded set of atomic counts: fast increment/decrement operations,
relatively slower summation of total counts (which need to happen much
less frequently).
WRR is showing a very high CPU cost relative to previous solutions, and
it's unclear why this is.
Add two metrics that should help us see the shape of the subchannel sets
that are being passed to high cost systems in order to confirm/deny
theories.
---------
Co-authored-by: ctiller <ctiller@users.noreply.github.com>
De-experiment pick first since we have both affinity and randomness E2E
test running successfully.
---------
Co-authored-by: Yash Tibrewal <yashkt@google.com>
Our current implementation of Join, TryJoin leverage some complicated
template stuff to work, which makes them hard to maintain. I've been
thinking about ways to simplify that for some time and had something
like this in mind - using a code generator that's at least a little more
understandable to code generate most of the complexity into a file that
is checkable.
Concurrently - I have a cool optimization in mind - but it requires that
we can move promises after polling, which is a contract change. I'm
going to work through the set of primitives we have in the coming weeks
and change that contract to enable the optimization.
---------
Co-authored-by: ctiller <ctiller@users.noreply.github.com>
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Fix sticky-TF behavior such that once we enter TRANSIENT_FAILURE, we do
not leave that state if we get a new address list.
Also, fix handling of subchannels in state TRANSIENT_FAILURE.
Previously, if a subchannel was already in state TRANSIENT_FAILURE when
we wanted to start a connection attempt on it (e.g., because the
subchannel already existed from a different channel, or because it
already existed in the previous subchannel list), we would wait for it
to report IDLE before attempting to connect. This PR changes pick_first
to instead immediately skip the subchannel and move on to the next one.
Now, the only time we wait for a subchannel in TRANSIENT_FAILURE is when
we wrap back around to the first subchannel in the list.
Our current implementation of `Seq`, `TrySeq` leverage some complicated
template stuff to work, which makes them hard to maintain. I've been
thinking about ways to simplify that for some time and had something
like this in mind - using a code generator that's at least a little more
understandable to code generate most of the complexity into a file that
is checkable.
Concurrently - I have a cool optimization in mind - but it requires that
we can move promises after polling, which is a contract change. I'm
going to work through the set of primitives we have in the coming weeks
and change that contract to enable the optimization.
---------
Co-authored-by: ctiller <ctiller@users.noreply.github.com>
We decided to not populate `policy_name` with the HTTP filter name in
xDS case. So removing it from `GenerateServiceConfig`. This will be
consistent across languages. The gRFC
[PR](https://github.com/grpc/proposal/pull/346) has been updated.
I have a cool optimization in mind for promises - but it requires that
we can move them after polling, which is a contract change. I'm going to
work through the set of primitives we have in the coming weeks and
change that contract to enable the optimization.
---------
Co-authored-by: ctiller <ctiller@users.noreply.github.com>
This PR adds in delegating call tracers that work like so -
If this is the first call tracer that is being added onto the call
context, just add it as earlier.
If this is the second call tracer that is being added onto the call
context, create a delegating call tracer that contains a list of call
tracers (including the first call tracer).
Any more call tracers added, just get added to the list of tracers in
the delegating call tracer.
(This is not yet used other than through tests.)
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This doesn't matter for gtest (it does its own sorting later), but for
the fuzzers this will probably save a bit of churn in the corpus and
lead to faster discovery of interesting cases.