Add this new "bbr" option to the list of the congestion control algorithms which
may be set by "quic-cc-algo" setting.
This new algorithm is considered as experimental and may be enabled only if
"expose-experimental-directive" is set.
Also update the documentation for this new setting.
Very few modifications: call ->on_transmit() and ->drs_on_transmit() congestion
control algorithm (quic_cc) callbacks from qc_send_ppkts() just after having
sents some packets.
qc_notify_cc_of_newly_acked_pkts() aim is to notify the congestion algorithm
of all the packet acknowledgements. It must call quic_cc_drs_update_rate_sample()
to update the delivery rate sampling information. It must also call
quic_cc_drs_on_ack_recv() to update the state of the delivery rate sampling part
used by BBR.
Finally, ->on_ack_rcvd() is called with the total number of bytes delivered
by the sender from the newly acknowledged packets with <bytes_delivered> as
parameter to do so. <pkt_delivered> store the per-packet number of bytes
delivered by the newly sent acknowledged packet (the packet with the highest
packet number). <bytes_lost> is also used and has been set by
qc_packet_loss_lookup() before calling qc_notify_cc_of_newly_acked_pkts().
qc_packet_loss_lookup() aim is to detect the packet losses. This is this function
which must called ->on_pkt_lost() BBR specific callback. It also set
<bytes_lost> passed parameter to the total number of bytes detected as lost upon
an ACK frame receipt for its caller.
Modify qc_release_lost_pkts() to call ->congestion_event() with the send time
from the newest packet detected as lost.
Modify qc_release_lost_pkts() to call ->slow_start() callback only if define
by the congestion control algorithm. This is not the case for BBR.
Add several callbacks to quic_cc_algo struct which are only called by BBR.
->get_drs() may be used to retrieve the delivery rate sampling information
from an congestion algorithm struct (quic_cc).
->on_transmit() must be called before sending any packet a QUIC sender.
->on_ack_rcvd() must be called after having received an ACK.
->on_pkt_lost() must be called after having detected a packet loss.
->congestion_event() must be called after any congestion event detection
Modify quic_cc.c to call ->event only if defined. This is not the case
for BBR.
Implement the version 3 of BBR for QUIC specified by the IETF in this draft:
https://datatracker.ietf.org/doc/draft-ietf-ccwg-bbr/
Here is an extract from the Abstract part to sum up the the capabilities of BBR:
BBR ("Bottleneck Bandwidth and Round-trip propagation time") uses recent
measurements of a transport connection's delivery rate, round-trip time, and
packet loss rate to build an explicit model of the network path. BBR then uses
this model to control both how fast it sends data and the maximum volume of data
it allows in flight in the network at any time. Relative to loss-based congestion
control algorithms such as Reno [RFC5681] or CUBIC [RFC9438], BBR offers
substantially higher throughput for bottlenecks with shallow buffers or random
losses, and substantially lower queueing delays for bottlenecks with deep buffers
(avoiding "bufferbloat"). BBR can be implemented in any transport protocol that
supports packet-delivery acknowledgment. Thus far, open source implementations
are available for TCP [RFC9293] and QUIC [RFC9000].
In haproxy, this implementation is considered as still experimental. It depends
on the newly implemented pacing feature.
BBR was asked in GH #2516 by @KazuyaKanemura, @osevan and @kennyZ96.
Implement the Kathleen Nichols' algorithm used by several congestion control
algorithm implementation (TCP/BBR in Linux kernel, QUIC/BBR in quiche) to track
the maximum value of a data type during a fixe time interval.
In this implementation, counters which are periodically reset are used in place
of timestamps.
Only the max part has been implemented.
(see lib/minmax.c implemenation for Linux kernel).
Add ->initial_wnd new member to quic_cc_path struct to keep the initial value
of the congestion window. This member is initialized as soon as a QUIC connection
is allocated. This modification is required for BBR congestion control algorithm.
-Ws on VTest is not working correctly for an unknown reason, the polling
of the NOTIFY_SOCKET seems to timeout, and VTest never receives the
READY message.
This patch disables the reg-tests using -Ws on OS X.
The -W mode implemented in VTest is not reliable anymore, because VTest
waits for the pidfile to be created. But with the new master-worker
mode, this file is created long before haproxy is ready. This can lead
to the test being started too soon, and failing from time to time.
The -Ws option allows to wait for haproxy to deliver a message to VTest
once it is ready.
0844bed7d3 ("MEDIUM: map/acl: Improve pat_ref_set() efficiency (for
"set-map", "add-acl" action perfs)") improved lookup efficiency for
set-map http action, but the core.set_map() lua method which is built
on the same construct was overlooked. Let's also benefit from this optim
as it easily applies.
In the doc our lists are indented but for any reason this one was not,
making it harder to visually delimit. Let's just indent it. No need to
backport this, it's totally cosmetic and would need adaptations since
it was recently touched.
There are some variables, which are set by HAProxy process (HAPROXY_*). Some
of them are handy to check or to redefine in the configuration, in order to
create conditional blocks and make the configuration more flexible. But it
wasn't clear in the documentation, which variables are really safe and usefull
to redefine and which ones could be only read via "show env" output.
Latest changes in master-worker architecture makes the existed description even
more confusing.
So let's sort all HAPROXY_* variables to four categories and let's also mark
explicitly, which ones are set in which process, when haproxy is started in
master-worker mode.
In addition, update examples in chapter "2.4. Conditional blocks". This might
bring more ideas for users how HAPROXY_* variables could be used in the
conditional blocks.
Before this patch HAPROXY_LOCALPEER variable could be set in init_early(),
in init_args() and in cfg_parse_global(). In master-worker mode, if localpeer
keyword set in the global section, HAPROXY_LOCALPEER in the worker
environment is set to this keyword's value, but in the master environment it
still keeps the default, a localhost name. This is confusing.
To fix it, let's set HAPROXY_LOCALPEER only once, when a worker or process in a
standalone mode has finished to parse its configuration. And let's set this
variable only for the worker process or for the process in a standalone mode,
because the master doesn't need it.
HAPROXY_LOCALPEER takes the value saved in localpeer global variable, which is
always set by default in init_early() to the local hostname. Then, localpeer
could be reset in init_args (-L option) and in cfg_parse_global() (while
parsing "localpeer" keyword).
Once in a while we find some makefiles ignoring some outdated arguments
and just emit a warning. What's annoying is that if users (say, distro
packagers), have purposely added ERR=1 to their build scripts to make
sure to fail on any warning, these ones will be ignored and the build
can continue with invalid or missing options.
William rightfully suggested that ERR=1 should also catch make's warnings
so this patch implements this, by creating a new "complain" variable that
points either to "error" or "warning" depending on $(ERR), and that is
used to send the messages using $(call $(complain),...). This does the
job right at little effort (tested from GNU make 3.82 to 4.3).
Note that for this purpose the ERR declaration was upped in the makefile
so that it appears before the new errors.mk file is included.
Since we build systemd.o for every target, we need it to be more
portable.
The SOCK_CLOEXEC argument from socket() is not portable and won't build
on some OS like macOS X.
This patch fixes the issue by replace SOCK_CLOEXEC by a fnctl set to
FD_CLOEXEC.
Build VTest temporarily from the sd-notify PR until the
https://github.com/vtest/VTest/pull/41 is merged.
This PR allows starting with -Ws in order to have more reliables tests
in master-worker mode.
Since sd_notify() is now implemented in src/systemd.c, there is no need
anymore to build its support conditionnally with USE_SYSTEMD.
This patch add supports for -Ws for every build and removes the
USE_SYSTEMD build option. It also remove every reference to USE_SYSTEMD
in the documentation and the CI.
This also allows to run the reg-tests in -Ws with the new VTest support.
A patch has recently tried to rename QUIC max-window-size global
parameter to default-max-window-size to better reflect its usage.
However, only the documentation was edited but not cfgparse-quic.c.
Fix this by updating cfgparse-quic.c with the new default- naming.
No need to backport.
As mentionned by Thayne McCombs in #2728, it could be handy to have a sample
fetch function to retrieve the query string with the question mark
character.
Indeed, for now, "query" sample fetch function already extract the query
string from the path, but the question mark character is not
included. Instead of adding a new sample fetch function with a too similar
name, an optional argument is added to "query". If "with_qm" is passed as
argument, the question mark will be included in the query string, but only
if it is not empty.
Thanks to this patch, the following rule:
http-request redirect location /destination?%[query] if { -m found query } some_condition
http-request redirect location /destination if some_condition
can now be expressed this way:
http-request redirect location /destination%[query(with_qm)] if some_condition
The server status must be adjusted, if necessary, at each retry. It is
properly performed when "obersve layer4" directive is set. But for the layer
7, only the last attempt was considered.
When the L7 retries were implemented, all retries were added before the
server status adjutement. So only the last attempt was considered. To fix
the issue, we must adjut the server status first, and then try to perform a
L7 retry.
This patch should fix the issue #2679. It must be backported to all stable
versions.
Conditional blocks inherit the same tokenizer and argument parser as
the rest of the configuration, but are also silently concatenated
around groups of spaces and tabs. This can lead to subtle failures
for configs containing spaces around commas and parenthesis, where
a string comparison might silently fail for example. Let's better
document this particular case.
Thanks to Valentine for analysing and reporting the problem.
This can be backported to 2.4.
Spaces around commas or parenthesis in expressions are generally part
of the value due to the long history of supporting unquoted arguments.
But this tends to come as a surprise to new users and sometimes creates
subtly invalid configurations. Let's add some text covering this.
This can be backported to 2.4.
tasklet_wakeup_on() and its derivates (tasklet_wakeup_after() and
tasklet_wakeup()) do not support passing a wakeup cause like
task_wakeup(). This is essentially due to an API limitation cause by
the fact that for a very long time the only reason for waking up was
to process pending I/O. But with the growing complexity of mux tasks,
it is becoming important to be able to skip certain heavy processing
when not strictly needed.
One possibility is to permit the caller of tasklet_wakeup() to pass
flags like task_wakeup(). Instead of going with a complex naming scheme,
let's simply make the flags optional and be zero when not specified. This
means that tasklet_wakeup_on() now takes either 2 or 3 args, and that the
third one is the optional flags to be passed to the callee. Eligible flags
are essentially the non-persistent ones (TASK_F_UEVT* and TASK_WOKEN_*)
which are cleared when the tasklet is executed. This way the handler
will find them in its <state> argument and will be able to distinguish
various causes for the call.
Everything in the tasklet layer supports flags, except that they are
just not implemented in the wakeup functions, while they are in the
task_wakeup functions. Initially it was not considered useful to pass
wakeup causes because these were essentially I/O, but with the growing
number of I/O handlers having to deal with various types of operations
(typically cheap I/O notifications on subscribe vs heavy parsing on
application-level wakeups), it would be nice to start to make this
distinction possible.
This commit extends _tasklet_wakeup_on() and _tasklet_wakeup_after()
to pass a set of flags that continues to be set as zero. For now this
changes nothing, but new functions will come.
Currently tasks being profiled have th_ctx->sched_call_date set to the
current nanosecond in monotonic time. But there's no other way to have
this, despite the scheduler being capable of it. Let's just declare a
new task flag, TASK_F_WANTS_TIME, that makes the scheduler take the time
just before calling the handler. This way, a task that needs nanosecond
resolution on the call date will be able to be called with an up-to-date
date without having to abuse now_mono_time() if not needed. In addition,
if CLOCK_MONOTONIC is not supported (now_mono_time() always returns 0),
the date is set to the most recently known now_ns, which is guaranteed
to be atomic and is only updated once per poll loop.
This date can be more conveniently retrieved using task_mono_time().
This can be useful, e.g. for pacing. The code was slightly adjusted so
as to merge the common parts between the profiling case and this one.
We used to store it in 32-bits since we'd only use it for latency and CPU
usage calculation but usages will evolve so let's not truncate the value
anymore. Now we store the full 64 bits. Note that this doesn't even
increase the storage size due to alignment. The 3 usage places were
verified to still be valid (most were already cast to 32 bits anyway).
In 2.7 was added a stream wakeup latency calculation with commit
6a28a30efa ("MINOR: tasks: do not keep cpu and latency times in struct
task"). However, due to the transformation of the previous code, it
kept unconditionally updating s->lat_time even of the sched_wake_date
was zero. In other words, s->lat_time is constantly updated for the
huge majority of calls that are made without profiling. Let's just
check the sched_wake_date status before doing so.
These are user-defined one-shot events that are application-specific
and reset upon wakeup and were not documented. No backport is needed
since these were added to 3.1.
Contrary to what the doc states, it is not expected (nor relevant) to
use yield-dependent methods such as core.yield() or core.(m)sleep() from
contexts that don't support yielding. Such contexts include body, init,
fetches and converters.
Thus the doc got it wrong since the beginning, because such methods were
never supported from the above contexts, yet it was listed in the list
of compatible contexts (probably the result of a copy-paste), which is
error-prone because it could either cause a Lua runtime error to be
thrown, or be ignored in some other cases.
It should be backported to all stable versions.
Every reg-test now runs without any warning, so let's acivate -dW by
default so the new ones will inheritate the option.
This patch reverts 9d511b3c ("REGTESTS: enable -dW on almost all tests
to fail on warnings") and adds -dW in the default HAPROXY_ARGS of
scripts/run-regtests.sh instead.
Most of the invalid or unknow field in the stats-file parser are ignored
silently, which is not the case of the frontend/backend mismatch on a
guid, which is kind of strange.
Since this is ""documented"" to be ignored in the
reg-tests/stats/sample-stats-file file, let's also ignore this kind of
line. This will allow to run the associated reg-test with -dW.
To improve debugging, extend "show quic" output to report if pacing is
activated on a connection. Two values will be displayed for pacing :
* a new counter paced_sent_ctr is defined in QCC structure. It will be
incremented each time an emission is interrupted due to pacing.
* pacing engine now saves the number of datagrams sent in the last paced
emission. This will be helpful to ensure burst parameter is valid.
Define a new QUIC congestion algorithm token 'cubic-pacing' for
quic-cc-algo bind keyword. This is identical to default cubic
implementation, except that pacing is used for STREAM frames emission.
This algorithm supports an extra argument to specify a burst size. This
is stored into a new bind_conf member named quic_pacing_burst which can
be reuse to initialize quic path.
Pacing support is still considered experimental. As such, 'cubic-pacing'
can only be used with expose-experimental-directives set.
Modify quic-cc-algo for better extensability of optional parameters
parsing. This will be useful to support a new parameter for maximum
allowed pacing burst size.
Take this opportunity to refine quic-cc-algo documentation. Optional
parameters are now presented as a list which would be soon extended.
A QUIC congestion algorithm can be specified on the bind line via
keyword quic-cc-algo. As such, bind_conf structure has a member
quic_cc_algo.
Previously, if quic-cc-algo was set, bind_conf member was initialized to
one of the globally defined CC algo structure. This patch changes
bind_conf quic_cc_algo initialization to point to a dynamically
allocated copy of CC algo structure.
With this change, it will be possible to tweak individually each CC algo
of a bind line. This will be used to activate pacing on top of the
congestion algorithm.
As bind_conf member is dynamically allocated now, its member is now
freed via free_proxy() to prevent any leak.
Support pacing emission for STREAM frames at the QUIC MUX layer. This is
implemented by adding a quic_pacer engine into QCC structure.
The main changes have been written into qcc_io_send(). It now
differentiates cases when some frames have been rejected by transport
layer. This can occur as previously due to congestion or FD buffer full,
which requires subscribing on transport layer. The new case is when
emission has been interrupted due to pacing timing. In this case, QUIC
MUX I/O tasklet is rescheduled to run with the flag TASK_F_USR1.
On tasklet execution, if TASK_F_USR1 is set, all standard processing for
emission and reception is skipped. Instead, a new function
qcc_purge_sending() is called. Its purpose is to retry emission with the
saved STREAM frames list. Either all remaining frames can now be send,
subscribe is done on transport error or tasklet must be rescheduled for
pacing purging.
In the meantime, if tasklet is rescheduled due to other conditions,
TASK_F_USR1 is reset. This will trigger a full regeneration of STREAM
frames. In this case, pacing expiration must be check before calling
qcc_send_frames() to ensure emission is now allowed.
QUIC MUX will be responsible to drive emission with pacing. This will be
implemented via setting TASK_F_USR1 before I/O tasklet wakeup. To
prepare this, encapsulate each I/O tasklet wakeup into a new function
qcc_wakeup().
This commit is purely refactoring prior to pacing implementation into
QUIC MUX.
For STREAM emission, MUX QUIC previously used a local list defined under
qcc_io_send(). This was suitable as either all frames were sent, or
emission must be interrupted due to transport congestion or fatal error.
In the latter case, the list was emptied anyway and a new frame list was
built on future qcc_io_send() invokation.
For pacing, MUX QUIC may have to save the frame list if pacing should be
applied across emission. This is necessary to avoid to unnecessarily
rebuilt stream frame list between each paced emission. To support this,
STREAM list is now stored as a member of QCC structure.
Ensure frame list is always deleted, even on QCC release, using newly
defined utility function qcc_tx_frms_free().
qc_send_mux() has been extended previously to support pacing emission.
This will ensure that no more than one datagram will be emitted during
each invokation. However, to achieve better performance, it may be
necessary to emit a batch of several datagrams one one turn.
A so-called burst value can be specified by the user in the
configuration. However, some congestion control algos may defined their
owned dynamic value. As such, a new CC callback pacing_burst is defined.
quic_cc_default_pacing_burst() can be used for algo without pacing
interaction, such as cubic. It will returns a static value based on user
selected configuration.
Pacing will be implemented for STREAM frames emission. As such,
qc_send_mux() API has been extended to add an argument to a quic_pacer
engine.
If non NULL, engine will be used to pace emission. In short, no more
than one datagram will be emitted for each qc_send_mux() invokation.
Pacer is then notified about the emission and a timer for a future
emission is calculated. qc_send_mux() will return PACING error value, to
inform QUIC MUX layer that it will be responsible to retry emission
after some delay.
Extend quic_pacer engine to support pacing emission. Several functions
are defined.
* quic_pacing_sent_done() to notify engine about an emission of one or
several datagrams
* quic_pacing_expired() to check if emission should be delayed or can be
conducted immediately
This commit is part of a adjustment on QUIC transport send API to
support pacing. Here, qc_send_mux() return type has been changed to use
a new enum quic_tx_err.
This is useful to explain different failure causes of emission. For now,
only two values have been defined : NONE and FATAL. When pacing will be
implemented, a new value would be added to specify that emission was
interrupted on pacing. This won't be a fatal error as this allows to
retry emission but not immediately.
Extend QUIC transport emission function to support a maximum datagram
argument. The purpose is to ensure that qc_send() won't emit more than
the specified value, unless it is 0 which is considered as unlimited.
In qc_prep_pkts(), a counter of built datagram has been added to support
this. The packet building loop is interrupted if it reaches a specified
maximum value. Also, its return value has been changed to the number of
prepared datagrams. This is reused by qc_send() to interrupt its work if
a specified max datagram argument value is reached over one or several
iteration of prepared/sent datagrams.
This change is necessary to support pacing emission. Note that ideally,
the total length in bytes of emitted datagrams should be taken into
account instead of the raw number of datagrams. However, for a first
implementation, it was deemed easier to implement it with the latter.
Frederic Lecaille
William Lallemand
Aurelien DARRAGON
Willy Tarreau
Valentine Krasnobaeva
Amaury Denoyelle
Christopher Faulet