This is done by passing the right stream's proxy (the frontend or the backend,
depending on the context) to lock the error snapshot used to store the error
info.
The stick table API was slightly reworked:
A global spin lock on stick table was added to perform lookup and
insert in a thread safe way. The handling of refcount on entries
is now handled directly by stick tables functions under protection
of this lock and was removed from the code of callers.
The "stktable_store" function is no more externalized and users should
now use "stktable_set_entry" in any case of insertion. This last one performs
a lookup followed by a store if not found. So the code using "stktable_store"
was re-worked.
Lookup, and set_entry functions automatically increase the refcount
of the returned/stored entry.
The function "sticktable_touch" was renamed "sticktable_touch_local"
and is now able to decrease the refcount if last arg is set to true. It
is allowing to release the entry without taking the lock twice.
A new function "sticktable_touch_remote" is now used to insert
entries coming from remote peers at the right place in the update tree.
The code of peer update was re-worked to use this new function.
This function is also able to decrease the refcount if wanted.
The function "stksess_kill" also handle a parameter to decrease
the refcount on the entry.
A read/write lock is added on each entry to protect the data content
updates of the entry.
A lock for LB parameters has been added inside the proxy structure and atomic
operations have been used to update server variables releated to lb.
The only significant change is about lb_map. Because the servers status are
updated in the sync-point, we can call recalc_server_map function synchronously
in map_set_server_status_up/down function.
Now, each proxy contains a lock that must be used when necessary to protect
it. Moreover, all proxy's counters are now updated using atomic operations.
First, we use atomic operations to update jobs/totalconn/actconn variables,
listener's nbconn variable and listener's counters. Then we add a lock on
listeners to protect access to their information. And finally, listener queues
(global and per proxy) are also protected by a lock. Here, because access to
these queues are unusal, we use the same lock for all queues instead of a global
one for the global queue and a lock per proxy for others.
2 global locks have been added to protect, respectively, the run queue and the
wait queue. And a process mask has been added on each task. Like for FDs, this
mask is used to know which threads are allowed to process a task.
For many tasks, all threads are granted. And this must be your first intension
when you create a new task, else you have a good reason to make a task sticky on
some threads. This is then the responsibility to the process callback to lock
what have to be locked in the task context.
Nevertheless, all tasks linked to a session must be sticky on the thread
creating the session. It is important that I/O handlers processing session FDs
and these tasks run on the same thread to avoid conflicts.
Many changes have been made to do so. First, the fd_updt array, where all
pending FDs for polling are stored, is now a thread-local array. Then 3 locks
have been added to protect, respectively, the fdtab array, the fd_cache array
and poll information. In addition, a lock for each entry in the fdtab array has
been added to protect all accesses to a specific FD or its information.
For pollers, according to the poller, the way to manage the concurrency is
different. There is a poller loop on each thread. So the set of monitored FDs
may need to be protected. epoll and kqueue are thread-safe per-se, so there few
things to do to protect these pollers. This is not possible with select and
poll, so there is no sharing between the threads. The poller on each thread is
independant from others.
Finally, per-thread init/deinit functions are used for each pollers and for FD
part for manage thread-local ressources.
Now, you must be carefull when a FD is created during the HAProxy startup. All
update on the FD state must be made in the threads context and never before
their creation. This is mandatory because fd_updt array is thread-local and
initialized only for threads. Because there is no pollers for the main one, this
array remains uninitialized in this context. For this reason, listeners are now
enabled in run_thread_poll_loop function, just like the worker pipe.
log buffers and static variables used in log functions are now thread-local. So
there is no need to lock anything to log messages. Moreover, per-thread
init/deinit functions are now used to initialize these buffers.
Email alerts relies on checks to send emails. The link between a mailers section
and a proxy was resolved during the configuration parsing, But initialization was
done when the first alert is triggered. This implied memory allocations and
tasks creations. With this patch, everything is now initialized during the
configuration parsing. So when an alert is triggered, only the memory required
by this alert is dynamically allocated.
Moreover, alerts processing had a flaw. The task handler used to process alerts
to be sent to the same mailer, process_email_alert, was designed to give back
the control to the scheduler when an alert was sent. So there was a delay
between the sending of 2 consecutives alerts (the min of
"proxy->timeout.connect" and "mailer->timeout.mail"). To fix this problem, now,
we try to process as much queued alerts as possible when the task is woken up.
This is a huge patch with many changes, all about the DNS. Initially, the idea
was to update the DNS part to ease the threads support integration. But quickly,
I started to refactor some parts. And after several iterations, it was
impossible for me to commit the different parts atomically. So, instead of
adding tens of patches, often reworking the same parts, it was easier to merge
all my changes in a uniq patch. Here are all changes made on the DNS.
First, the DNS initialization has been refactored. The DNS configuration parsing
remains untouched, in cfgparse.c. But all checks have been moved in a post-check
callback. In the function dns_finalize_config, for each resolvers, the
nameservers configuration is tested and the task used to manage DNS resolutions
is created. The links between the backend's servers and the resolvers are also
created at this step. Here no connection are kept alive. So there is no needs
anymore to reopen them after HAProxy fork. Connections used to send DNS queries
will be opened on demand.
Then, the way DNS requesters are linked to a DNS resolution has been
reworked. The resolution used by a requester is now referenced into the
dns_requester structure and the resolution pointers in server and dns_srvrq
structures have been removed. wait and curr list of requesters, for a DNS
resolution, have been replaced by a uniq list. And Finally, the way a requester
is removed from a DNS resolution has been simplified. Now everything is done in
dns_unlink_resolution.
srv_set_fqdn function has been simplified. Now, there is only 1 way to set the
server's FQDN, independently it is done by the CLI or when a SRV record is
resolved.
The static DNS resolutions pool has been replaced by a dynamoc pool. The part
has been modified by Baptiste Assmann.
The way the DNS resolutions are triggered by the task or by a health-check has
been totally refactored. Now, all timeouts are respected. Especially
hold.valid. The default frequency to wake up a resolvers is now configurable
using "timeout resolve" parameter.
Now, as documented, as long as invalid repsonses are received, we really wait
all name servers responses before retrying.
As far as possible, resources allocated during DNS configuration parsing are
releases when HAProxy is shutdown.
Beside all these changes, the code has been cleaned to ease code review and the
doc has been updated.
It was painful not to have the status code available, especially when
it was computed. Let's store it and ensure we don't claim content-length
anymore on 1xx, only 0 body bytes.
This patch reorganize the shctx API in a generic storage API, separating
the shared SSL session handling from its core.
The shctx API only handles the generic data part, it does not know what
kind of data you use with it.
A shared_context is a storage structure allocated in a shared memory,
allowing its usage in a multithread or a multiprocess context.
The structure use 2 linked list, one containing the available blocks,
and another for the hot locked blocks. At initialization the available
list is filled with <maxblocks> blocks of size <blocksize>. An <extra>
space is initialized outside the list in case you need some specific
storage.
+-----------------------+--------+--------+--------+--------+----
| struct shared_context | extra | block1 | block2 | block3 | ...
+-----------------------+--------+--------+--------+--------+----
<-------- maxblocks --------->
* blocksize
The API allows to store content on several linked blocks. For example,
if you allocated blocks of 16 bytes, and you want to store an object of
60 bytes, the object will be allocated in a row of 4 blocks.
The API was made for LRU usage, each time you get an object, it pushes
the object at the end of the list. When it needs more space, it discards
The functions name have been renamed in a more logical way, the part
regarding shctx have been prefixed by shctx_ and the functions for the
shared ssl session cache have been prefixed by sh_ssl_sess_.
Move the ssl callback functions of the ssl shared session cache to
ssl_sock.c. The shctx functions still needs to be separated of the ssl
tree and data.
When compiled with Openssl >= 1.1.1, before attempting to do the handshake,
try to read any early data. If any early data is present, then we'll create
the session, read the data, and handle the request before we're doing the
handshake.
For this, we add a new connection flag, CO_FL_EARLY_SSL_HS, which is not
part of the CO_FL_HANDSHAKE set, allowing to proceed with a session even
before an SSL handshake is completed.
As early data do have security implication, we let the origin server know
the request comes from early data by adding the "Early-Data" header, as
specified in this draft from the HTTP working group :
https://datatracker.ietf.org/doc/html/draft-ietf-httpbis-replay
This one may be called by upper layers (eg: si_shutw()) or lower layers
(si_shutw() as well during stream_int_notify()) so we want it to take
care of updating the connection's flags if it's not going to be done
by the caller.
In transport-layer functions (snd_buf/rcv_buf), it's very problematic
never to know if polling changes made to the connection will be propagated
or not. This has led to some conn_cond_update_polling() calls being placed
at a few places to cover both the cases where the function is called from
the upper layer and when it's called from the lower layer. With the arrival
of the MUX, this becomes even more complicated, as the upper layer will not
have to manipulate anything from the connection layer directly and will not
have to push such updates directly either. But the snd_buf functions will
need to see their updates committed when called from upper layers.
The solution here is to introduce a connection flag set by the connection
handler (and possibly any other similar place) indicating that the caller
is committed to applying such changes on return. This way, the called
functions will be able to apply such changes by themselves before leaving
when the flag is not set, and the upper layer will not have to care about
that anymore.
This flag is only used when reading using splicing for now, and is only
set when a pipe full condition is met, so we can simplify its reset
condition in conn_refresh_polling_flags so that it's cleared at the
same time as the other ones, only when the control layer is ready.
This flag could be used more, to mark that a buffer full condition was
met with any receive method in order to simplify polling management.
This should probably be revisited after 1.8.
BoringSSL switch OPENSSL_VERSION_NUMBER to 1.1.0 for compatibility.
Fix BoringSSL call and openssl-compat.h/#define occordingly.
This will not break openssl/libressl compat.
Now only conn_full_close() will be used. It will become more obvious
when the tracking is in place or not and will make it easier to
convert remaining call places to conn_streams.
Instead of having to manually handle lingering outside, let's make
conn_sock_shutw() check for it before calling shutdown(). We simply
don't want to emit the FIN if we're going to reset the connection
due to lingering. It's particularly important for silent-drop where
it's absolutely mandatory that no packet leaves the machine.
These flags are not exactly for the data layer, they instead indicate
what is expected from the transport layer. Since we're going to split
the connection between the transport and the data layers to insert a
mux layer, it's important to have a clear idea of what each layer does.
All function conn_data_* used to manipulate these flags were renamed to
conn_xprt_*.
The HTTP/2->HTTP/1 gateway will need to process HTTP/1 responses. We
cannot sanely rely on the HTTP/1 txn to parse a response because :
1) responses generated by haproxy such as error messages, redirects,
stats or Lua are neither parsed nor indexed ; this could be
addressed over the long term but will take time.
2) the http txn is useless to parse the body : the states present there
are only meaningful to received bytes (ie next bytes to parse) and
not at all to sent bytes. Thus chunks cannot be followed at all.
Even when implementing this later, it's unsure whether it will be
possible when dealing with compression.
So using the HTTP txn is now out of the equation and the only remaining
solution is to call an HTTP/1 message parser. We already have one, it was
slightly modified to avoid keeping states by benefitting from the fact
that the response was produced by haproxy and this is entirely available.
It assumes the following rules are true, or that incuring an extra cost
to work around them is acceptable :
- the response buffer is read-write and supports modifications in place
- headers sent through / by haproxy are not folded. Folding is still
implemented by replacing CR/LF/tabs/spaces with spaces if encountered
- HTTP/0.9 responses are never sent by haproxy and have never been
supported at all
- haproxy will not send partial responses, the whole headers block will
be sent at once ; this means that we don't need to keep expensive
states and can afford to restart the parsing from the beginning when
facing a partial response ;
- response is contiguous (does not wrap). This was already the case
with the original parser and ensures we can safely dereference all
fields with (ptr,len)
The parser replaces all of the http_msg fields that were necessary with
local variables. The parser is not called on an http_msg but on a string
with a start and an end. The HTTP/1 states were reused for ease of use,
though the request-specific ones have not been implemented for now. The
error position and error state are supported and optional ; these ones
may be used later for bug hunting.
The parser issues the list of all the headers into a caller-allocated
array of struct ist.
The content-length/transfer-encoding header are checked and the relevant
info fed the h1 message state (flags + body_len).
The chunk crlf parser used to depend on the channel and on the HTTP
message, eventhough it's not really needed. Let's remove this dependency
so that it can be used within the H2 to H1 gateway.
As part of this small API change, it was renamed to h1_skip_chunk_crlf()
to mention that it doesn't depend on http_msg anymore.
The chunk parser used to depend on the channel and on the HTTP message
but it's not really needed as they're only used to retrieve the buffer
as well as to return the number of bytes parsed and the chunk size.
Here instead we pass the (few) relevant information in arguments so that
the function may be reused without a channel nor an HTTP message (ie
from the H2 to H1 gateway).
As part of this API change, it was renamed to h1_parse_chunk_size() to
mention that it doesn't depend on http_msg anymore.
Functions http_parse_chunk_size(), http_skip_chunk_crlf() and
http_forward_trailers() were moved to h1.h and h1.c respectively so
that they can be called from outside. The parts that were inline
remained inline as it's critical for performance (+41% perf
difference reported in an earlier test). For now the "http_" prefix
remains in their name since they still depend on the http_msg type.
Certain types and enums are very specific to the HTTP/1 parser, and we'll
need to share them with the HTTP/2 to HTTP/1 translation code. Let's move
them to h1.c/h1.h. Those with very few occurrences or only used locally
were renamed to explicitly mention the relevant HTTP version :
enum ht_state -> h1_state.
http_msg_state_str -> h1_msg_state_str
HTTP_FLG_* -> H1_FLG_*
http_char_classes -> h1_char_classes
Others like HTTP_IS_*, HTTP_MSG_* are left to be done later.
Fix regression introduced by commit:
'MAJOR: servers: propagate server status changes asynchronously.'
The building of the log line was re-worked to be done at the
postponed point without lack of data.
[wt: this only affects 1.8-dev, no backport needed]
There's no point having the channel marked writable as these functions
only extract data from the channel. The code was retrieved from their
ci/co ancestors.
For HTTP/2 we'll need some buffer-only equivalent functions to some of
the ones applying to channels and still squatting the bi_* / bo_*
namespace. Since these names have kept being misleading for quite some
time now and are really getting annoying, it's time to rename them. This
commit will use "ci/co" as the prefix (for "channel in", "channel out")
instead of "bi/bo". The following ones were renamed :
bi_getblk_nc, bi_getline_nc, bi_putblk, bi_putchr,
bo_getblk, bo_getblk_nc, bo_getline, bo_getline_nc, bo_inject,
bi_putchk, bi_putstr, bo_getchr, bo_skip, bi_swpbuf
In order to prepare multi-thread development, code was re-worked
to propagate changes asynchronoulsy.
Servers with pending status changes are registered in a list
and this one is processed and emptied only once 'run poll' loop.
Operational status changes are performed before administrative
status changes.
In a case of multiple operational status change or admin status
change in the same 'run poll' loop iteration, those changes are
merged to reach only the targeted status.
Instead of duplicating some sensitive listener-specific code in the
session and in the stream code, let's call listener_release() when
releasing a connection attached to a listener.
This function is used to create a series of listeners for a specific
address and a port range. It automatically calls the matching protocol
handlers to add them to the relevant lists. This way cfgparse doesn't
need to manipulate listeners anymore. As an added bonus, the memory
allocation is checked.
Since everything is self contained in proto_uxst.c there's no need to
export anything. The same should be done for proto_tcp.c but the file
contains other stuff that's not related to the TCP protocol itself
and which should first be moved somewhere else.
