Proposed new TS API function: TSHttp2GraceShutdown

[Fei Deng <du...@apache.org>]

TSReturnCode TSHttp2GraceShutdown(TSHttpTxn txnp)

With this new API, plugins can request a grace shutdown by sending GOAWAY
frames (https://httpwg.org/specs/rfc7540.html#GOAWAY).

This will also replace this PR
https://github.com/apache/trafficserver/pull/11046

Fei Deng

Re: Proposed new TS API function: TSHttp2GraceShutdown

[Fei Deng <du...@apache.org>]

I didn't find a specific test that tests for connection close in H2, so I
wrote a simple one this morning and confirmed that changing the header with
hook TS_HTTP_SEND_RESPONSE_HDR_HOOK works. We'll have a discussion this
afternoon to discuss it over.

On Mon, Jun 17, 2024 at 10:52 PM Fei Deng <du...@gmail.com> wrote:

> Because of this?
> https://github.com/apache/trafficserver/pull/11046#discussion_r1583528415
>
> The code in the HttpTransact.cc that checks for the header removes the
> header and never adds it back if it is a http2 connection.
>
> In an internal discussion in Yahoo I mentioned we can probably find a
> exact moment to set the header, such that it happens after the check for
> the whole “connection: keep-alive” and “connection: close” in
> HttpTransact.cc, but at the end it was deemed too complicated, and a simple
> flag set by an api might be easier for the plugins to use.
>
> Do we have a test for that feature mentioned in the docs?
>
>
> Regards,
> Fei Deng
>
> Sent from my iPhone
>
>
> On Mon, Jun 17, 2024 at 10:45 PM Masakazu Kitajo <ma...@apache.org>
> wrote:
>
>> It's a documented feature.
>>
>> https://docs.trafficserver.apache.org/en/9.2.x/admin-guide/plugins/header_rewrite.en.html#close-connections-for-draining
>>
>> https://docs.trafficserver.apache.org/en/latest/admin-guide/plugins/header_rewrite.en.html#close-connections-for-draining
>>
>> On Mon, Jun 17, 2024 at 8:32 PM Masakazu Kitajo <ma...@apache.org>
>> wrote:
>>
>> > Purposefully? Where did it happen? I'd say it was broken. We have that
>> use
>> > case and need a FIX.
>> >
>> > Masakazu
>> >
>> > On Mon, Jun 17, 2024 at 6:47 PM Fei Deng <du...@apache.org> wrote:
>> >
>> >> Actually it’s not possible by setting the “Connection: close” header.
>> That
>> >> was the initial intention of PR #11046, but with all the discussions it
>> >> looks like that functionality was taken out purposefully.
>> >>
>> >> Regards,
>> >> Fei Deng
>> >>
>> >> Sent from my iPhone
>> >>
>> >>
>> >> On Mon, Jun 17, 2024 at 8:42 PM Masakazu Kitajo <ma...@apache.org>
>> >> wrote:
>> >>
>> >> > It has been possible by setting "Connection: Close" header, which
>> means
>> >> > that a server wants no more requests on the connection and wants to
>> >> close
>> >> > it.
>> >> >
>> >> > If you want to close a connection on some conditions, you could check
>> >> the
>> >> > conditions and set the header by header_rewrite (or any plugins). And
>> >> those
>> >> > plugins that used to work for H1 do the same for H2 as well without
>> any
>> >> > changes (and probably for H3 as well, though it's not implemented
>> yet).
>> >> >
>> >> > From plugins' perspective, everything on ATS is HTTP/1. Headers are
>> >> > converted to H1 representation (e.g. ":authority" -> "Host"). It's
>> >> > natural to use the H1 interface between ATS core and plugins. In that
>> >> way,
>> >> > plugins don't even need to know/check the HTTP version. I don't think
>> >> > having something just for H2 is a right thing, unless it's truly an
>> H2
>> >> > specific thing (e.g. setting max H2 frame size). I didn't use "2"
>> even
>> >> for
>> >> > ServerPush because I knew H3 was already coming.
>> >> >
>> >> > Masakazu
>> >> >
>> >> > On Mon, Jun 17, 2024 at 9:34 AM Fei Deng <du...@apache.org>
>> wrote:
>> >> >
>> >> > > TSReturnCode TSHttp2GraceShutdown(TSHttpTxn txnp)
>> >> > >
>> >> > > With this new API, plugins can request a grace shutdown by sending
>> >> GOAWAY
>> >> > > frames (https://httpwg.org/specs/rfc7540.html#GOAWAY).
>> >> > >
>> >> > > This will also replace this PR
>> >> > > https://github.com/apache/trafficserver/pull/11046
>> >> > >
>> >> > > Fei Deng
>> >> > >
>> >> >
>> >>
>> >
>>
>

Re: Proposed new TS API function: TSHttp2GraceShutdown

[Fei Deng <du...@apache.org>]

Ok, after a short discussion with Brian Neradt, we've decided that a few
tweaks to the current PR
https://github.com/apache/trafficserver/pull/11046 should
work. I've added a test to make sure the feature (setting "Connection:
close" drains the H2 connection) works as intended.

On Tue, Jun 18, 2024 at 12:27 PM Masakazu Kitajo <ma...@apache.org> wrote:

> PR 8178 says:
> > With this change adding a header-rewrite rule to add the
> Connection:closed header will still work to trigger the draining logic. But
> core logic to clean up HTTP/1.x connections will not trigger the draining
> logic.
>
> It doesn't sound like the feature was taken out purposefully. I still think
> it was broken at some point if it doesn't work, and it should be restored.
> When the feature was added on 8.x we didn't have good tools to test it. We
> might be able to test it now with ProxyVerifier. Lack of tests should not
> be used as justification to silently kill features.
>
> I do see the complication, but that's inside the core. I don't see how
> adding the API, which requires plugins to check HTTP version and do
> different things for each version, can be easier for the plugins to use.
> The version number in the name should be removed at a minimum (i.e. the API
> should work for every HTTP version).
>
> Masakazu
>
>
> On Mon, Jun 17, 2024 at 8:52 PM Fei Deng <du...@gmail.com> wrote:
>
> > Because of this?
> >
> https://github.com/apache/trafficserver/pull/11046#discussion_r1583528415
> >
> > The code in the HttpTransact.cc that checks for the header removes the
> > header and never adds it back if it is a http2 connection.
> >
> > In an internal discussion in Yahoo I mentioned we can probably find a
> exact
> > moment to set the header, such that it happens after the check for the
> > whole “connection: keep-alive” and “connection: close” in
> HttpTransact.cc,
> > but at the end it was deemed too complicated, and a simple flag set by an
> > api might be easier for the plugins to use.
> >
> > Do we have a test for that feature mentioned in the docs?
> >
> >
> > Regards,
> > Fei Deng
> >
> > Sent from my iPhone
> >
> >
> > On Mon, Jun 17, 2024 at 10:45 PM Masakazu Kitajo <ma...@apache.org>
> > wrote:
> >
> > > It's a documented feature.
> > >
> > >
> >
> https://docs.trafficserver.apache.org/en/9.2.x/admin-guide/plugins/header_rewrite.en.html#close-connections-for-draining
> > >
> > >
> >
> https://docs.trafficserver.apache.org/en/latest/admin-guide/plugins/header_rewrite.en.html#close-connections-for-draining
> > >
> > > On Mon, Jun 17, 2024 at 8:32 PM Masakazu Kitajo <ma...@apache.org>
> > wrote:
> > >
> > > > Purposefully? Where did it happen? I'd say it was broken. We have
> that
> > > use
> > > > case and need a FIX.
> > > >
> > > > Masakazu
> > > >
> > > > On Mon, Jun 17, 2024 at 6:47 PM Fei Deng <du...@apache.org>
> wrote:
> > > >
> > > >> Actually it’s not possible by setting the “Connection: close”
> header.
> > > That
> > > >> was the initial intention of PR #11046, but with all the discussions
> > it
> > > >> looks like that functionality was taken out purposefully.
> > > >>
> > > >> Regards,
> > > >> Fei Deng
> > > >>
> > > >> Sent from my iPhone
> > > >>
> > > >>
> > > >> On Mon, Jun 17, 2024 at 8:42 PM Masakazu Kitajo <ma...@apache.org>
> > > >> wrote:
> > > >>
> > > >> > It has been possible by setting "Connection: Close" header, which
> > > means
> > > >> > that a server wants no more requests on the connection and wants
> to
> > > >> close
> > > >> > it.
> > > >> >
> > > >> > If you want to close a connection on some conditions, you could
> > check
> > > >> the
> > > >> > conditions and set the header by header_rewrite (or any plugins).
> > And
> > > >> those
> > > >> > plugins that used to work for H1 do the same for H2 as well
> without
> > > any
> > > >> > changes (and probably for H3 as well, though it's not implemented
> > > yet).
> > > >> >
> > > >> > From plugins' perspective, everything on ATS is HTTP/1. Headers
> are
> > > >> > converted to H1 representation (e.g. ":authority" -> "Host"). It's
> > > >> > natural to use the H1 interface between ATS core and plugins. In
> > that
> > > >> way,
> > > >> > plugins don't even need to know/check the HTTP version. I don't
> > think
> > > >> > having something just for H2 is a right thing, unless it's truly
> an
> > H2
> > > >> > specific thing (e.g. setting max H2 frame size). I didn't use "2"
> > even
> > > >> for
> > > >> > ServerPush because I knew H3 was already coming.
> > > >> >
> > > >> > Masakazu
> > > >> >
> > > >> > On Mon, Jun 17, 2024 at 9:34 AM Fei Deng <du...@apache.org>
> > wrote:
> > > >> >
> > > >> > > TSReturnCode TSHttp2GraceShutdown(TSHttpTxn txnp)
> > > >> > >
> > > >> > > With this new API, plugins can request a grace shutdown by
> sending
> > > >> GOAWAY
> > > >> > > frames (https://httpwg.org/specs/rfc7540.html#GOAWAY).
> > > >> > >
> > > >> > > This will also replace this PR
> > > >> > > https://github.com/apache/trafficserver/pull/11046
> > > >> > >
> > > >> > > Fei Deng
> > > >> > >
> > > >> >
> > > >>
> > > >
> > >
> >
>

Re: Proposed new TS API function: TSHttp2GraceShutdown

[Masakazu Kitajo <ma...@apache.org>]

PR 8178 says:
> With this change adding a header-rewrite rule to add the
Connection:closed header will still work to trigger the draining logic. But
core logic to clean up HTTP/1.x connections will not trigger the draining
logic.

It doesn't sound like the feature was taken out purposefully. I still think
it was broken at some point if it doesn't work, and it should be restored.
When the feature was added on 8.x we didn't have good tools to test it. We
might be able to test it now with ProxyVerifier. Lack of tests should not
be used as justification to silently kill features.

I do see the complication, but that's inside the core. I don't see how
adding the API, which requires plugins to check HTTP version and do
different things for each version, can be easier for the plugins to use.
The version number in the name should be removed at a minimum (i.e. the API
should work for every HTTP version).

Masakazu


On Mon, Jun 17, 2024 at 8:52 PM Fei Deng <du...@gmail.com> wrote:

> Because of this?
> https://github.com/apache/trafficserver/pull/11046#discussion_r1583528415
>
> The code in the HttpTransact.cc that checks for the header removes the
> header and never adds it back if it is a http2 connection.
>
> In an internal discussion in Yahoo I mentioned we can probably find a exact
> moment to set the header, such that it happens after the check for the
> whole “connection: keep-alive” and “connection: close” in HttpTransact.cc,
> but at the end it was deemed too complicated, and a simple flag set by an
> api might be easier for the plugins to use.
>
> Do we have a test for that feature mentioned in the docs?
>
>
> Regards,
> Fei Deng
>
> Sent from my iPhone
>
>
> On Mon, Jun 17, 2024 at 10:45 PM Masakazu Kitajo <ma...@apache.org>
> wrote:
>
> > It's a documented feature.
> >
> >
> https://docs.trafficserver.apache.org/en/9.2.x/admin-guide/plugins/header_rewrite.en.html#close-connections-for-draining
> >
> >
> https://docs.trafficserver.apache.org/en/latest/admin-guide/plugins/header_rewrite.en.html#close-connections-for-draining
> >
> > On Mon, Jun 17, 2024 at 8:32 PM Masakazu Kitajo <ma...@apache.org>
> wrote:
> >
> > > Purposefully? Where did it happen? I'd say it was broken. We have that
> > use
> > > case and need a FIX.
> > >
> > > Masakazu
> > >
> > > On Mon, Jun 17, 2024 at 6:47 PM Fei Deng <du...@apache.org> wrote:
> > >
> > >> Actually it’s not possible by setting the “Connection: close” header.
> > That
> > >> was the initial intention of PR #11046, but with all the discussions
> it
> > >> looks like that functionality was taken out purposefully.
> > >>
> > >> Regards,
> > >> Fei Deng
> > >>
> > >> Sent from my iPhone
> > >>
> > >>
> > >> On Mon, Jun 17, 2024 at 8:42 PM Masakazu Kitajo <ma...@apache.org>
> > >> wrote:
> > >>
> > >> > It has been possible by setting "Connection: Close" header, which
> > means
> > >> > that a server wants no more requests on the connection and wants to
> > >> close
> > >> > it.
> > >> >
> > >> > If you want to close a connection on some conditions, you could
> check
> > >> the
> > >> > conditions and set the header by header_rewrite (or any plugins).
> And
> > >> those
> > >> > plugins that used to work for H1 do the same for H2 as well without
> > any
> > >> > changes (and probably for H3 as well, though it's not implemented
> > yet).
> > >> >
> > >> > From plugins' perspective, everything on ATS is HTTP/1. Headers are
> > >> > converted to H1 representation (e.g. ":authority" -> "Host"). It's
> > >> > natural to use the H1 interface between ATS core and plugins. In
> that
> > >> way,
> > >> > plugins don't even need to know/check the HTTP version. I don't
> think
> > >> > having something just for H2 is a right thing, unless it's truly an
> H2
> > >> > specific thing (e.g. setting max H2 frame size). I didn't use "2"
> even
> > >> for
> > >> > ServerPush because I knew H3 was already coming.
> > >> >
> > >> > Masakazu
> > >> >
> > >> > On Mon, Jun 17, 2024 at 9:34 AM Fei Deng <du...@apache.org>
> wrote:
> > >> >
> > >> > > TSReturnCode TSHttp2GraceShutdown(TSHttpTxn txnp)
> > >> > >
> > >> > > With this new API, plugins can request a grace shutdown by sending
> > >> GOAWAY
> > >> > > frames (https://httpwg.org/specs/rfc7540.html#GOAWAY).
> > >> > >
> > >> > > This will also replace this PR
> > >> > > https://github.com/apache/trafficserver/pull/11046
> > >> > >
> > >> > > Fei Deng
> > >> > >
> > >> >
> > >>
> > >
> >
>

Re: Proposed new TS API function: TSHttp2GraceShutdown

[Fei Deng <du...@gmail.com>]

Because of this?
https://github.com/apache/trafficserver/pull/11046#discussion_r1583528415

The code in the HttpTransact.cc that checks for the header removes the
header and never adds it back if it is a http2 connection.

In an internal discussion in Yahoo I mentioned we can probably find a exact
moment to set the header, such that it happens after the check for the
whole “connection: keep-alive” and “connection: close” in HttpTransact.cc,
but at the end it was deemed too complicated, and a simple flag set by an
api might be easier for the plugins to use.

Do we have a test for that feature mentioned in the docs?


Regards,
Fei Deng

Sent from my iPhone


On Mon, Jun 17, 2024 at 10:45 PM Masakazu Kitajo <ma...@apache.org> wrote:

> It's a documented feature.
>
> https://docs.trafficserver.apache.org/en/9.2.x/admin-guide/plugins/header_rewrite.en.html#close-connections-for-draining
>
> https://docs.trafficserver.apache.org/en/latest/admin-guide/plugins/header_rewrite.en.html#close-connections-for-draining
>
> On Mon, Jun 17, 2024 at 8:32 PM Masakazu Kitajo <ma...@apache.org> wrote:
>
> > Purposefully? Where did it happen? I'd say it was broken. We have that
> use
> > case and need a FIX.
> >
> > Masakazu
> >
> > On Mon, Jun 17, 2024 at 6:47 PM Fei Deng <du...@apache.org> wrote:
> >
> >> Actually it’s not possible by setting the “Connection: close” header.
> That
> >> was the initial intention of PR #11046, but with all the discussions it
> >> looks like that functionality was taken out purposefully.
> >>
> >> Regards,
> >> Fei Deng
> >>
> >> Sent from my iPhone
> >>
> >>
> >> On Mon, Jun 17, 2024 at 8:42 PM Masakazu Kitajo <ma...@apache.org>
> >> wrote:
> >>
> >> > It has been possible by setting "Connection: Close" header, which
> means
> >> > that a server wants no more requests on the connection and wants to
> >> close
> >> > it.
> >> >
> >> > If you want to close a connection on some conditions, you could check
> >> the
> >> > conditions and set the header by header_rewrite (or any plugins). And
> >> those
> >> > plugins that used to work for H1 do the same for H2 as well without
> any
> >> > changes (and probably for H3 as well, though it's not implemented
> yet).
> >> >
> >> > From plugins' perspective, everything on ATS is HTTP/1. Headers are
> >> > converted to H1 representation (e.g. ":authority" -> "Host"). It's
> >> > natural to use the H1 interface between ATS core and plugins. In that
> >> way,
> >> > plugins don't even need to know/check the HTTP version. I don't think
> >> > having something just for H2 is a right thing, unless it's truly an H2
> >> > specific thing (e.g. setting max H2 frame size). I didn't use "2" even
> >> for
> >> > ServerPush because I knew H3 was already coming.
> >> >
> >> > Masakazu
> >> >
> >> > On Mon, Jun 17, 2024 at 9:34 AM Fei Deng <du...@apache.org> wrote:
> >> >
> >> > > TSReturnCode TSHttp2GraceShutdown(TSHttpTxn txnp)
> >> > >
> >> > > With this new API, plugins can request a grace shutdown by sending
> >> GOAWAY
> >> > > frames (https://httpwg.org/specs/rfc7540.html#GOAWAY).
> >> > >
> >> > > This will also replace this PR
> >> > > https://github.com/apache/trafficserver/pull/11046
> >> > >
> >> > > Fei Deng
> >> > >
> >> >
> >>
> >
>

Re: Proposed new TS API function: TSHttp2GraceShutdown

[Masakazu Kitajo <ma...@apache.org>]

It's a documented feature.
https://docs.trafficserver.apache.org/en/9.2.x/admin-guide/plugins/header_rewrite.en.html#close-connections-for-draining
https://docs.trafficserver.apache.org/en/latest/admin-guide/plugins/header_rewrite.en.html#close-connections-for-draining

On Mon, Jun 17, 2024 at 8:32 PM Masakazu Kitajo <ma...@apache.org> wrote:

> Purposefully? Where did it happen? I'd say it was broken. We have that use
> case and need a FIX.
>
> Masakazu
>
> On Mon, Jun 17, 2024 at 6:47 PM Fei Deng <du...@apache.org> wrote:
>
>> Actually it’s not possible by setting the “Connection: close” header. That
>> was the initial intention of PR #11046, but with all the discussions it
>> looks like that functionality was taken out purposefully.
>>
>> Regards,
>> Fei Deng
>>
>> Sent from my iPhone
>>
>>
>> On Mon, Jun 17, 2024 at 8:42 PM Masakazu Kitajo <ma...@apache.org>
>> wrote:
>>
>> > It has been possible by setting "Connection: Close" header, which means
>> > that a server wants no more requests on the connection and wants to
>> close
>> > it.
>> >
>> > If you want to close a connection on some conditions, you could check
>> the
>> > conditions and set the header by header_rewrite (or any plugins). And
>> those
>> > plugins that used to work for H1 do the same for H2 as well without any
>> > changes (and probably for H3 as well, though it's not implemented yet).
>> >
>> > From plugins' perspective, everything on ATS is HTTP/1. Headers are
>> > converted to H1 representation (e.g. ":authority" -> "Host"). It's
>> > natural to use the H1 interface between ATS core and plugins. In that
>> way,
>> > plugins don't even need to know/check the HTTP version. I don't think
>> > having something just for H2 is a right thing, unless it's truly an H2
>> > specific thing (e.g. setting max H2 frame size). I didn't use "2" even
>> for
>> > ServerPush because I knew H3 was already coming.
>> >
>> > Masakazu
>> >
>> > On Mon, Jun 17, 2024 at 9:34 AM Fei Deng <du...@apache.org> wrote:
>> >
>> > > TSReturnCode TSHttp2GraceShutdown(TSHttpTxn txnp)
>> > >
>> > > With this new API, plugins can request a grace shutdown by sending
>> GOAWAY
>> > > frames (https://httpwg.org/specs/rfc7540.html#GOAWAY).
>> > >
>> > > This will also replace this PR
>> > > https://github.com/apache/trafficserver/pull/11046
>> > >
>> > > Fei Deng
>> > >
>> >
>>
>

Re: Proposed new TS API function: TSHttp2GraceShutdown

[Masakazu Kitajo <ma...@apache.org>]

Purposefully? Where did it happen? I'd say it was broken. We have that use
case and need a FIX.

Masakazu

On Mon, Jun 17, 2024 at 6:47 PM Fei Deng <du...@apache.org> wrote:

> Actually it’s not possible by setting the “Connection: close” header. That
> was the initial intention of PR #11046, but with all the discussions it
> looks like that functionality was taken out purposefully.
>
> Regards,
> Fei Deng
>
> Sent from my iPhone
>
>
> On Mon, Jun 17, 2024 at 8:42 PM Masakazu Kitajo <ma...@apache.org> wrote:
>
> > It has been possible by setting "Connection: Close" header, which means
> > that a server wants no more requests on the connection and wants to close
> > it.
> >
> > If you want to close a connection on some conditions, you could check the
> > conditions and set the header by header_rewrite (or any plugins). And
> those
> > plugins that used to work for H1 do the same for H2 as well without any
> > changes (and probably for H3 as well, though it's not implemented yet).
> >
> > From plugins' perspective, everything on ATS is HTTP/1. Headers are
> > converted to H1 representation (e.g. ":authority" -> "Host"). It's
> > natural to use the H1 interface between ATS core and plugins. In that
> way,
> > plugins don't even need to know/check the HTTP version. I don't think
> > having something just for H2 is a right thing, unless it's truly an H2
> > specific thing (e.g. setting max H2 frame size). I didn't use "2" even
> for
> > ServerPush because I knew H3 was already coming.
> >
> > Masakazu
> >
> > On Mon, Jun 17, 2024 at 9:34 AM Fei Deng <du...@apache.org> wrote:
> >
> > > TSReturnCode TSHttp2GraceShutdown(TSHttpTxn txnp)
> > >
> > > With this new API, plugins can request a grace shutdown by sending
> GOAWAY
> > > frames (https://httpwg.org/specs/rfc7540.html#GOAWAY).
> > >
> > > This will also replace this PR
> > > https://github.com/apache/trafficserver/pull/11046
> > >
> > > Fei Deng
> > >
> >
>

Re: Proposed new TS API function: TSHttp2GraceShutdown

[Fei Deng <du...@apache.org>]

Actually it’s not possible by setting the “Connection: close” header. That
was the initial intention of PR #11046, but with all the discussions it
looks like that functionality was taken out purposefully.

Regards,
Fei Deng

Sent from my iPhone


On Mon, Jun 17, 2024 at 8:42 PM Masakazu Kitajo <ma...@apache.org> wrote:

> It has been possible by setting "Connection: Close" header, which means
> that a server wants no more requests on the connection and wants to close
> it.
>
> If you want to close a connection on some conditions, you could check the
> conditions and set the header by header_rewrite (or any plugins). And those
> plugins that used to work for H1 do the same for H2 as well without any
> changes (and probably for H3 as well, though it's not implemented yet).
>
> From plugins' perspective, everything on ATS is HTTP/1. Headers are
> converted to H1 representation (e.g. ":authority" -> "Host"). It's
> natural to use the H1 interface between ATS core and plugins. In that way,
> plugins don't even need to know/check the HTTP version. I don't think
> having something just for H2 is a right thing, unless it's truly an H2
> specific thing (e.g. setting max H2 frame size). I didn't use "2" even for
> ServerPush because I knew H3 was already coming.
>
> Masakazu
>
> On Mon, Jun 17, 2024 at 9:34 AM Fei Deng <du...@apache.org> wrote:
>
> > TSReturnCode TSHttp2GraceShutdown(TSHttpTxn txnp)
> >
> > With this new API, plugins can request a grace shutdown by sending GOAWAY
> > frames (https://httpwg.org/specs/rfc7540.html#GOAWAY).
> >
> > This will also replace this PR
> > https://github.com/apache/trafficserver/pull/11046
> >
> > Fei Deng
> >
>

Re: Proposed new TS API function: TSHttp2GraceShutdown

[Masakazu Kitajo <ma...@apache.org>]

It has been possible by setting "Connection: Close" header, which means
that a server wants no more requests on the connection and wants to close
it.

If you want to close a connection on some conditions, you could check the
conditions and set the header by header_rewrite (or any plugins). And those
plugins that used to work for H1 do the same for H2 as well without any
changes (and probably for H3 as well, though it's not implemented yet).

From plugins' perspective, everything on ATS is HTTP/1. Headers are
converted to H1 representation (e.g. ":authority" -> "Host"). It's
natural to use the H1 interface between ATS core and plugins. In that way,
plugins don't even need to know/check the HTTP version. I don't think
having something just for H2 is a right thing, unless it's truly an H2
specific thing (e.g. setting max H2 frame size). I didn't use "2" even for
ServerPush because I knew H3 was already coming.

Masakazu

On Mon, Jun 17, 2024 at 9:34 AM Fei Deng <du...@apache.org> wrote:

> TSReturnCode TSHttp2GraceShutdown(TSHttpTxn txnp)
>
> With this new API, plugins can request a grace shutdown by sending GOAWAY
> frames (https://httpwg.org/specs/rfc7540.html#GOAWAY).
>
> This will also replace this PR
> https://github.com/apache/trafficserver/pull/11046
>
> Fei Deng
>