Instead of waiting for the connection layer to let us know we can read,
attempt to receive as soon as process_stream() is called, and subscribe
to receive events if we can't receive yet.
Now, except for idle connections, the recv(), send() and wake() methods are
no more, all the lower layers do is waking tasklet for anybody waiting
for I/O events.
Change fctl_list and send_list to be lists of struct wait_list, and nuke
send_wait_list, as it's now redundant.
Make the code responsible for shutr/shutw subscribe to those lists.
Instead of having our wake() method called each time a fd event happens,
just subscribe to recv/send events, and get our tasklet called when that
happens. If any recv/send was possible, the equivalent of what h2_wake_cb()
will be done.
Let the connection layer know we're always interested in getting more data,
so that we get scheduled as soon as data is available, instead of relying
on the wake() method.
Make h2_recv() and h2_send() return 1 if data has been sent/received, or 0
if it did not. That way the caller will be able to know if more work may
have to be done.
Remove the recv() method from mux and conn_stream.
The goal is to always receive from the upper layers, instead of waiting
for the connection later. For now, recv() is still called from the wake()
method, but that should change soon.
For struct connection, struct conn_stream, and for the h2 mux, add 2 new
lists, one that handles waiters for recv, and one that handles waiters for
recv and send. That way we can ask to subscribe for either recv or send.
Resetting the polling flags at the end of conn_fd_handler() shouldn't be
needed anymore, and it will create problem when we won't handle send/recv
from conn_fd_handler() anymore.
In tasklet_free(), if we're currently in the runnable task list, don't
forget to decrement taks_list_size, or it'll end up being to big, and we may
not process tasks in the global runqueue.
Cyril Bonté reported that commit f9cc07c25b broke the build without
thread.
We don't need to initialise tid = 0 in mworker_loop, so we could
completely remove it.
Christopher noticed that the CS_FL_EOS to CS_FL_REOS conversion was
incomplete : when the connectionis closed, we mark the streams with EOS
instead of REOS, causing the loss of any possibly pending data. At the
moment it's not an issue since H2 is used only with a client, but with
servers it could be a real problem if servers close the connection right
after sending their response.
This patch should be backported to 1.8.
This patch ensures that a DNS resolution may be launched before
setting a server FQDN via the CLI. Especially, it checks that
resolvers was set.
A LEVEL 4 reg testing file is provided.
Thanks to Lukas Tribus for having reported this issue.
Must be backported to 1.8.
This is a python wrapper which creates a socketpair and passes it as two
environment variable to haproxy.
It's the easiest way to test the sockpair protocol in haproxy.
This protocol is based on the uxst one, but it uses socketpair and FD
passing insteads of a connect()/accept().
The "sockpair@" prefix has been implemented for both bind and server
keywords.
When HAProxy wants to connect through a sockpair@, it creates 2 new
sockets using the socketpair() syscall and pass one of the socket
through the FD specified on the server line.
On the bind side, haproxy will receive the FD, and will use it like it
was the FD of an accept() syscall.
This protocol was designed for internal communication within HAProxy
between the master and the workers, but it's possible to use it
externaly with a wrapper and pass the FD through environment variabls.
It's possible to have several protocols per family which is a problem
with the current way the protocols are stored.
This allows to register a new protocol in HAProxy which is not a
protocol in the strict socket definition. It will be used to register a
SOCK_STREAM protocol using socketpair().
In _update_fd(), if the fd wasn't polled, and we don't want it to be polled,
we just returned 0, however, we should return changes instead, or all previous
changes will be lost.
This should be backported to 1.8.
The following functions only deal with header field values and are agnostic
to the HTTP version so they were moved to http.c :
http_header_match2(), find_hdr_value_end(), find_cookie_value_end(),
extract_cookie_value(), parse_qvalue(), http_find_url_param_pos(),
http_find_next_url_param().
Those lacking the "http_" prefix were modified to have it.
There are 3 tables in proto_http which are used exclusively by logs :
hdr_encode_map[], url_encode_map[] and http_encode_map[]. They indicate
what characters are safe to be emitted in logs depending on the part of
the message where they are placed. Let's move this to log.c, as well as
its initialization. It's worth noting that the rfc5424 map was already
initialized there.
These error codes and messages are agnostic to the version, even if
they are represented as HTTP/1.0 messages. Ultimately they will have
to be transformed into internal HTTP messages to be used everywhere.
The HTTP/1.1 100 Continue message was turned to an IST and the local
copy in the Lua code was removed.
This function is purely HTTP once http_txn is put aside. So the original
one was renamed to http_txn_get_path() and it extracts the relevant offsets
from the txn to pass them to http_get_path(). One benefit of the new version
is that it returns the length at the same time so that allowed to slightly
simplify http_get_path_from_string() which had to look up the end pointer
previously and which is not needed anymore.
It's a bit painful to have to deal with HTTP semantics for each protocol
version (H1 and H2), and working on the version-agnostic code further
emphasizes the problem.
This patch creates http.h and http.c which are agnostic to the version
in use, and which borrow a few parts from proto_http and from h1. For
example the once thought h1-specific h1_char_classes array is in fact
dictated by RFC7231 and is used to parse HTTP headers. A few changes
were made to a few files which were including proto_http.h while they
only needed http.h.
Certain string definitions pre-dated the introduction of indirect
strings (ist) so some were used to simplify the definition of the known
HTTP methods. The current lookup code saves 2 kB of a heavily used table
and is faster than the previous table based lookup (typ. 14 ns vs 16
before).
We need to clean the FDs registered manually in the poller to avoid FD
leaking during a reload of the master.
This patch call the per thread deinit function which close the thread
waker pipe.
In order to communicate with the workers, the master pipe has been
replaced by a socketpair() per worker.
The goal is to use these sockets as stats sockets and be able to access
them from the master.
When reloading, the master serialize the information of the workers and
put them in a environment variable. Once the master has been reexecuted
it unserialize that information and it is capable of closing the FDs of
the leaving children.
The master now use a poll loop, which should be initialized even in wait
mode. We need to init some variables if we didn't success to load the
configuration file.
If haproxy failed to load its configuration, the process is reexecuted
and it did not init the poller. So we must not try to deinit the poller
before the exec().
With the new way of handling the signals in the master worker, we are
are not staying in a waitpid() loop. Which means that we need to catch the
SIGCHLD signals to call waitpid().
The problem is when the master is reloading, this signal is neither
registered nor blocked so we lost all signals between the restart and
the call to mworker_loop().
This patch blocks the SIGCHLD signals before the reloading and ensure
it's not unblocked before the master registered the SIGCHLD handler.
In order to reorganize the code of the master worker, the mworker_wait()
function which was the main function was split. This function was
handling a wait() loop, but it does not need it anymore since the code
will use the poll loop of haproxy instead.
The function was split in several functions:
- mworker_catch_sigterm() which is a signal handler for SIGTERM ans
SIGUSR1 that sends the signals to the workers
- mworker_catch_sigchld() which is the code handling the leaving of a
child
- mworker_catch_sighup which basically call the mworker_restart()
function
- mworker_loop() which is the function calling the main poll loop in the
master
Instead of having a separate area for the captured data, we now have a
contigous block made of the descriptor and the data. At the moment, since
the area is dynamically allocated, we can adjust its size to what is
needed, but the idea is to quickly switch to a pool and an LRU list.
Now upon error we dynamically allocate the snapshot instead of overwriting
it. This way there is no more memory wasted in the proxy to hold the two
error snapshot descriptors. Also an appreciable side effect of this is that
the proxy's lock is only taken during the pointer swap, no more while copying
the buffer's contents. This saves 480 bytes of memory per proxy.
The proxy's lock it held while filling the error but not while dumping
it, so it's possible to dereference pointers being replaced, typically
server pointers. The risk is very low and unlikely but not inexistent.
Since "show errors" is rarely used in parallel, let's simply grab the
proxy's lock while dumping. Ideally we should use an R/W lock here but
it will not make any difference.
This patch must be backported to 1.8, but the code is in proto_http.c
there, though mostly similar.
Now that we have a generic error capture function, let's simplify
http_capture_bad_message() to make use of it. At this point the API
is not changed at all, but it could be further simplified.
This function now captures an error regardless of its side and protocol.
The caller must pass a number of elements and may pass a protocol-specific
structure and a callback to display it. Later this function may deal with
more advanced allocation techniques to avoid allocating as many buffers
as proxies.
The HTTP dumps are now configurable in the code : "show errors" now
calls a protocol-specific function to emit the decoded output. For
now only HTTP is implemented.
The output of "show errors" was slightly reordered to split the HTTP part
in a single chunk_appendf() call. The useless buffer total input was
replaced to report the buffer's start offset, which is the offset in the
stream of the first input byte (thus not counting output). Also it was
the opportunity to stop calling the stream "session".
The idea will be to make the error snapshot feature accessible to other
protocols than just HTTP. This patch only introduces an "http_snapshot"
structure and renames a few fields to make things more explicit. The
HTTP part was installed inside a union so that we can easily add more
protocols in the future.
The snapshots have the ability to restart a partial dump and they use
the stream ID as the restart point. Since it's purely HTTP, let's use
the event ID instead.
Let's use an atomic increment for the error snapshot, as we'd rather
not assign the same ID to two errors happening in parallel. It's very
unlikely that it will ever happen though.
This patch must be backported to 1.8 with the other one it relies on
("MINOR: thread: implement HA_ATOMIC_XADD()").
On the Mailing list, Marcos Moreno reported that haproxy configuration
validation (through "haproxy -c cfgfile") does not detect when a
resolvers section does not exist for a server.
That said, this checking is done after HAProxy has started up.
The problem is that this can create production issue, since init
script can't detect the problem before starting / reloading HAProxy.
To fix this issue, this patch registers the function which validates DNS
configuration validity and run it right after configuration parsing is
finished (through cfg_register_postparser()).
Thanks to it, now "haproxy -c cfgfile" will fail when a server
points to a non-existing resolvers section (or any other validation made
by the function above).
Backport status: 1.8
