This one enforces a per-process connection rate limit, regardless of what
may be set per frontend. It can be a way to limit the CPU usage of a process
being severely attacked.
The side effect is that the global process connection rate is now measured
for each incoming connection, so it will be possible to report it.
This option permits to change the global maxconn setting within the
limit that was set by the initial value, which is now reported as the
hard maxconn value. This allows to immediately accept more concurrent
connections or to stop accepting new ones until the value passes below
the indicated setting.
The main use of this option is on systems where many haproxy instances
are loaded and admins need to re-adjust resource sharing at run time
to regain a bit of fairness between processes.
Trailing spaces after headers were not trimmed, only the leading ones
were. An issue was detected today with a content-length value which
was padded with spaces and which was rejected. Recent updates to the
http-bis draft made it a lot more clear that such spaces must be ignored,
so this is what this patch does.
It should be backported to 1.4.
Many inet_ntop calls were partially right, which was hard to detect given
the complex combinations. Some of them were relying on the listener's proto
instead of the address itself, which could have been different when dealing
with an accept-proxy connection.
The new addr_to_str() function does the dirty job and returns the family, which
makes it particularly suited to calls from switch/case statements. A large number
of if/else statements were removed and the stats output could even be cleaned up
in the case of session dump.
As a side effect of doing this, the resulting code is smaller by almost 1kB.
All changed parts have been tested and provided expected output.
Some older libc don't define splice() and and don't define _syscall*()
either, which causes build errors if splicing is enabled.
To solve this, we now split the syscall redefinition into two layers :
- one file per syscall (epoll, splice)
- one common file to declare the _syscall*() macros
The code is cleaner because files using the syscalls just have to include
their respective file. It's not adviced to merge multiple syscall families
into a same file if all are not intended to be used simultaneously, because
defining unused static functions causes warnings to be emitted during build.
As a result, the new USE_MY_SPLICE parameter was added in order to be able
to define the splice() syscall separately.
If "option forwardfor" has the "if-none" argument, then the header is
only added when the request did not already have one. This option has
security implications, and should not be set blindly.
Manoj Kumar reported a case where haproxy would crash upon start-up. The
cause was an "http-check expect" statement declared in the defaults section,
which caused a NULL regex to be used during the check. This statement is not
allowed in defaults sections precisely because this requires saving a copy
of the regex in the default proxy. But the check was not made to prevent it
from being declared there, hence the issue.
Instead of adding code to detect its abnormal use, we decided to implement
it. It was not that much complex because the expect_str part was not used
with regexes, so it could hold the string form of the regex in order to
compile it again for every backend (there's no way to clone regexes).
This patch has been tested and works. So it's both a bugfix and a minor
feature enhancement.
It should be backported to 1.4 though it's not critical since the config
was not supposed to be supported.
Adding health checks has become a real pain, with cross-references to all
checks everywhere because they're all a single bit. Since they're all
exclusive, let's change this to have a check number only. We reserve 4
bits allowing up to 16 checks (15+tcp), only 7 of which are currently
used. The code has shrunk by almost 1kB and we saved a few option bits.
The "dispatch" option has been moved to px->options, making a few tests
a bit cleaner.
This patch provides a new "option redis-check" statement to enable server health checks based on redis PING request (http://www.redis.io/commands/ping).
This global task is used to periodically check for end of resource shortage
and to try to enable queued listeners again. This is important in case some
temporary system-wide shortage is encountered, so that we don't have to wait
for an existing connection to be released before checking the queue again.
For situations where listeners are queued due to the global maxconn being
reached, the task is woken up at least every second. For situations where
a system resource shortage is detected (memory, sockets, ...) the task is
woken up at least every 100 ms. That way, recovery from severe events can
still be achieved under acceptable conditions.
This was revealed with one of the very latest patches which caused
the listener_queue not to be initialized on the stats socket frontend.
And in fact a number of other ones were missing too. This is getting so
boring that now we'll always make use of the same function to initialize
any proxy. Doing so has even saved about 500 bytes on the binary due to
the avoided code redundancy.
No backport is needed.
This function is finally not needed anymore, as it has been replaced with
a per-proxy task that is scheduled when some limits are encountered on
incoming connections or when the process is stopping. The savings should
be noticeable on configs with a large number of proxies. The most important
point is that the rate limiting is now enforced in a clean and solid way.
Those states have been replaced with PR_STFULL and PR_STREADY respectively,
as it is what matches them the best now. Also, two occurrences of PR_STIDLE
in peers.c have been removed as this did not provide any form of error recovery
anyway.
All listeners that are limited by a proxy-specific resource are now
queued at the proxy's and not globally. This allows finer-grained
wakeups when releasing resource.
When an accept() fails because of a connection limit or a memory shortage,
we now disable it and queue it so that it's dequeued only when a connection
is released. This has improved the behaviour of the process near the fd limit
as now a listener with a no connection (eg: stats) will not loop forever
trying to get its connection accepted.
The solution is still not 100% perfect, as we'd like to have this used when
proxy limits are reached (use a per-proxy list) and for safety, we'd need
to have dedicated tasks to periodically re-enable them (eg: to overcome
temporary system-wide resource limitations when no connection is released).
When a listeners encounters a resource shortage, it currently stops until
one re-enables it. This is far from being perfect as it does not yet handle
the case where the single connection from the listener is rejected (eg: the
stats page).
Now we'll have a special status for resource limited listeners and we'll
queue them into one or multiple lists. That way, each time we have to stop
a listener because of a resource shortage, we can enqueue it and change its
state, so that it is dequeued once more resources are available.
This patch currently does not change any existing behaviour, it only adds
the basic building blocks for doing that.
Managing listeners state is difficult because they have their own state
and can at the same time have theirs dictated by their proxy. The pause
is not done properly, as the proxy code is fiddling with sockets. By
introducing new functions such as pause_listener()/resume_listener(), we
make it a bit more obvious how/when they're supposed to be used. The
listen_proxies() function was also renamed to resume_proxies() since
it's only used for pause/resume.
This patch is the first in a series aiming at getting rid of the maintain_proxies
mess. In the end, proxies should not call enable_listener()/disable_listener()
anymore.
Patch af5149 introduced an issue which can be detected only on out of
memory conditions : a LIST_DEL() may be performed on an uninitialized
struct member instead of a LIST_INIT() during the accept() phase,
causing crashes and memory corruption to occur.
This issue was detected and diagnosed by the Exceliance R&D team.
This is 1.5-specific and very recent, so no existing deployment should
be impacted.
Never add connections allocated to this sever to a stick-table.
This may be used in conjunction with backup to ensure that
stick-table persistence is disabled for backup servers.
apsession_refresh() and apsess_refressh are only used inside apsession.c
and thus can be made static.
The only use of apsession_refresh() is appsession_task_init().
These functions have been re-ordered to avoid the need for
a forward-declaration of apsession_refresh().
If a connection is closed by because the backend became unavailable
then log 'D' as the termination condition.
Signed-off-by: Simon Horman <horms@verge.net.au>
This adds the "on-marked-down shutdown-sessions" statement on "server" lines,
which causes all sessions established on a server to be killed at once when
the server goes down. The task's priority is reniced to the highest value
(1024) so that servers holding many tasks don't cause a massive slowdown due
to the wakeup storm.
The motivation for this is to allow iteration of all the connections
of a server without the expense of iterating over the global list
of connections.
The first use of this will be to implement an option to close connections
associated with a server when is is marked as being down or in maintenance
mode.
* The declaration of peer_session_create() does
not match its definition. As it is only
used inside of peers.c make it static.
* Make the declaration of peers_register_table()
match its definition.
* Also, make all functions in peers.c that
are not also in peers.h static
Bashkim Kasa reported that the stats admin page did not work when colons
were used in server or backend names. This was caused by url-encoding
resulting in ':' being sent as '%3A'. Now we systematically decode the
field names and values to fix this issue.
It's more expensive to call splice() on short payloads than to use
recv()+send(). One of the reasons is that doing a splice() involves
allocating a pipe. One other reason is that the kernel will have to
copy itself if we try to splice less than a page. So let's fix a
short offset of 4kB below which we don't splice.
A quick test shows that on chunked encoded data, with splice we had
6826 syscalls (1715 splice, 3461 recv, 1650 send) while with this
patch, the same transfer resulted in 5793 syscalls (3896 recv, 1897
send).
There are some very rare server-to-server applications that abuse the HTTP
protocol and expect the payload phase to be highly interactive, with many
interleaved data chunks in both directions within a single request. This is
absolutely not supported by the HTTP specification and will not work across
most proxies or servers. When such applications attempt to do this through
haproxy, it works but they will experience high delays due to the network
optimizations which favor performance by instructing the system to wait for
enough data to be available in order to only send full packets. Typical
delays are around 200 ms per round trip. Note that this only happens with
abnormal uses. Normal uses such as CONNECT requests nor WebSockets are not
affected.
When "option http-no-delay" is present in either the frontend or the backend
used by a connection, all such optimizations will be disabled in order to
make the exchanges as fast as possible. Of course this offers no guarantee on
the functionality, as it may break at any other place. But if it works via
HAProxy, it will work as fast as possible. This option should never be used
by default, and should never be used at all unless such a buggy application
is discovered. The impact of using this option is an increase of bandwidth
usage and CPU usage, which may significantly lower performance in high
latency environments.
This change should be backported to 1.4 since the first report of such a
misuse was in 1.4. Next patch will also be needed.
This status code is used in response to requests matching "monitor-uri".
Some users need to adjust it to fit their needs (eg: make some strings
appear there). As it's already defined as a chunked string and used
exactly like other status codes, it makes sense to make it configurable
with the usual "errorfile", "errorloc", ...
John Helliwell reported a runtime issue on Solaris since 1.5-dev5. Traces
show that connect() returns EINVAL, which means the socket length is not
appropriate for the family. Solaris does not like being called with sizeof
and needs the address family's size on sockaddr_storage.
The fix consists in adding a get_addr_len() function which returns the
socket's address length based on its family. Tests show that this works
for both IPv4 and IPv6 addresses.
Since IPv6 is a different type than IPv4, the pattern fetch functions
src6 and dst6 were added. IPv6 stick-tables can also fetch IPv4 addresses
with src and dst. In this case, the IPv4 addresses are mapped to their
IPv6 counterpart, according to RFC 4291.
Since the latest additions to buffer_forward(), it became too large for
inlining, so let's uninline it. The code size drops by 3kB. Should be
backported to 1.4 too.
Despite much care around handling the content-length as a 64-bit integer,
forwarding was broken on 32-bit platforms due to the 32-bit nature of
the ->to_forward member of the "buffer" struct. The issue is that this
member is declared as a long, so while it works OK on 64-bit platforms,
32-bit truncate the content-length to the lower 32-bits.
One solution could consist in turning to_forward to a long long, but it
is used a lot in the critical path, so it's not acceptable to perform
all buffer size computations on 64-bit there.
The fix consists in changing the to_forward member to a strict 32-bit
integer and ensure in buffer_forward() that only the amount of bytes
that can fit into it is considered. Callers of buffer_forward() are
responsible for checking that their data were taken into account. We
arbitrarily ensure we never consider more than 2G at once.
That's the way it was intended to work on 32-bit platforms except that
it did not.
This issue was tracked down hard at Exosec with Bertrand Jacquin,
Thierry Fournier and Julien Thomas. It remained undetected for a long
time because files larger than 4G are almost always transferred in
chunked-encoded format, and most platforms dealing with huge contents
these days run on 64-bit.
The bug affects all 1.5 and 1.4 versions, and must be backported.
The parser now distinguishes between pure addresses and address:port. This
is useful for some config items where only an address is required.
Raw IPv6 addresses are now parsed, but IPv6 host name resolution is still not
handled (gethostbyname does not resolve IPv6 names to addresses).
This option enables use of the PROXY protocol with the server, which
allows haproxy to transport original client's address across multiple
architecture layers.
Upon connection establishment, stream_sock is now able to send a PROXY
line before sending any data. Since it's possible that the buffer is
already full, and we don't want to allocate a block for that line, we
compute it on-the-fly when we need it. We just store the offset from
which to (re-)send from the end of the line, since it's assumed that
multiple outputs of the same proxy line will be strictly equivalent. In
practice, one call is enough. We just make sure to handle the case where
the first send() would indicate an incomplete output, eventhough it's
very unlikely to ever happen.
And also rename "req_acl_rule" "http_req_rule". At the beginning that
was a bit confusing to me, especially the "req_acl" list which in fact
holds what we call rules. After some digging, it appeared that some
part of the code is 100% HTTP and not just related to authentication
anymore, so let's move that part to HTTP and keep the auth-only code
in auth.c.
It's very annoying that frontend and backend stats are merged because we
don't know what we're observing. For instance, if a "listen" instance
makes use of a distinct backend, it's impossible to know what the bytes_out
means.
Some points take care of not updating counters twice if the backend points
to the frontend, indicating a "listen" instance. The thing becomes more
complex when we try to add support for server side keep-alive, because we
have to maintain a pointer to the backend used for last request, and to
update its stats. But we can't perform such comparisons anymore because
the counters will not match anymore.
So in order to get rid of this situation, let's have both frontend AND
backend stats in the "struct proxy". We simply update the relevant ones
during activity. Some of them are only accounted for in the backend,
while others are just for frontend. Maybe we can improve a bit on that
later, but the essential part is that those counters now reflect what
they really mean.
This patch turns internal server addresses to sockaddr_storage to
store IPv6 addresses, and makes the connect() function use it. This
code already works but some caveats with getaddrinfo/gethostbyname
still need to be sorted out while the changes had to be merged at
this stage of internal architecture changes. So for now the config
parser will not emit an IPv6 address yet so that user experience
remains unchanged.
This change should have absolutely zero user-visible effect, otherwise
it's a bug introduced during the merge, that should be reported ASAP.
This one has been removed and is now totally superseded by ->target.
To get the server, one must use target_srv(&s->target) instead of
s->srv now.
The function ensures that non-server targets still return NULL.
s->prev_srv is used by assign_server() only, but all code paths leading
to it now take s->prev_srv from the existing s->srv. So assign_server()
can do that copy into its own stack.
If at one point a different srv is needed, we still have a copy of the
last server on which we failed a connection attempt in s->target.
When dealing with HTTP keep-alive, we'll have to know if we can reuse
an existing connection. For that, we'll have to check if the current
connection was made on the exact same target (referenced in the stream
interface).
Thus, we need to first assign the next target to the session, then
copy it to the stream interface upon connect(). Later we'll check for
equivalence between those two operations.
Till now we used the fact that the dispatch address was not null to use
the dispatch mode. This is very unconvenient, so let's have a dedicated
option.
This is in fact where those parts belong to. The old data_state was replaced
by applet.state and is now initialized when the applet is registered. It's
worth noting that the applet does not need to know the session nor the
buffer anymore since everything is brought by the stream interface.
It is possible that having a separate applet struct would simplify the
code but that's not a big deal.
Now that we have the target pointer and type in the stream interface,
we don't need the applet.handler pointer anymore. That makes the code
somewhat cleaner because we know we're dealing with an applet by checking
its type instead of checking the pointer is not null.
When doing a connect() on a stream interface, some information is needed
from the server and from the backend. In some situations, we don't have
a server and only a backend (eg: peers). In other cases, we know we have
an applet and we don't want to connect to anything, but we'd still like
to have the info about the applet being used.
For this, we now store a pointer to the "target" into the stream interface.
The target describes what's on the other side before trying to connect. It
can be a server, a proxy or an applet for now. Later we'll probably have
descriptors for multiple-stage chains so that the final information may
still be found.
This will help removing many specific cases in the code. It already made
it possible to remove the "srv" and "be" parameters to tcpv4_connect_server().
Those 3 parts are the buffer side, the remote side and the communication
functions. This change has no functional effect but is needed to proceed
further.
I/O handlers are still delicate to manipulate. They have no type, they're
just raw functions which have no knowledge of themselves. Let's have them
declared as applets once for all. That way we can have multiple applets
share the same handler functions and we can store their names there. When
we later need to add more parameters (eg: usage stats), we'll be able to
do so in the applets themselves.
The CLI functions has been prefixed with "cli" instead of "stats" as it's
clearly what is going on there.
The applet descriptor in the stream interface should get all the applet
specific data (st0, ...) but this will be done in the next patch so that
we don't pollute this one too much.
Till now, the forwarding code was making use of the hdr_content_len member
to hold the size of the last chunk parsed. As such, it was reset after being
scheduled for forwarding. The issue is that this entry was reset before the
data could be viewed by backend.c in order to parse a POST body, so the
"balance url_param check_post" did not work anymore.
In order to fix this, we need two things :
- the chunk size (reset upon every forward)
- the total body size (not reset)
hdr_content_len was thus replaced by the former (hence the size of the patch)
as it makes more sense to have it stored that way than the way around.
This patch should be backported to 1.4 with care, considering that it affects
the forwarding code.
I have written a small patch to enable a correct PostgreSQL health check
It works similar to mysql-check with the very same parameters.
E.g.:
listen pgsql 127.0.0.1:5432
mode tcp
option pgsql-check user pgsql
server masterdb pgsql.server.com:5432 check inter 10000
One of the requirements we have is to run multiple instances of haproxy on a
single host; this is so that we can split the responsibilities (and change
permissions) between product teams. An issue we ran up against is how we
would distinguish between the logs generated by each instance. The solution
we came up with (please let me know if there is a better way) is to override
the application tag written to syslog. We can then configure syslog to write
these to different files.
I have attached a patch adding a global option 'log-tag' to override the
default syslog tag 'haproxy' (actually defaults to argv[0]).
Haproxy does not include the hostname rather the IP of the machine in
the syslog headers it sends. Unfortunately this means that for each log
line rsyslog does a reverse dns on the client IP and in the case of
non-routable IPs one gets the public hostname not the internal one.
While this is valid according to RFC3164 as one might imagine this is
troublsome if you have some machines with public IPs, internal IPs, no
reverse DNS entries, etc and you want a standardized hostname based log
directory structure. The rfc says the preferred value is the hostname.
This patch adds a global "log-send-hostname" statement which accepts an
optional string to force the host name. If unset, the local host name
is used.
HTTP pipelining currently needs to monitor the response buffer to wait
for some free space to be able to send a response. It was not possible
for the HTTP analyser to be called based on response buffer activity.
Now we introduce a new buffer flag BF_WAKE_ONCE which is set when the
HTTP request analyser is set on the response buffer and some activity
is detected. This is not clean at all but once of the only ways to fix
the issue before we make it possible to register events for analysers.
Also it appeared that one realign condition did not cover all cases.
This counter will help quickly spot whether there are new errors or not.
It is also assigned to each capture so that a script can keep trace of
which capture was taken when.
Debugging parsing errors can be greatly improved if we know what the parser
state was and what the buffer flags were (especially for closed inputs/outputs
and full buffers). Let's add that to the error snapshots.
When the number of servers is a multiple of the size of the input set,
map-based hash can be inefficient. This typically happens with 64
servers when doing URI hashing. The "avalanche" hash-type applies an
avalanche hash before performing a map lookup in order to smooth the
distribution. The result is slightly less smooth than the map for small
numbers of servers, but still better than the consistent hashing.
We'll use this hash at other places, let's make it globally available.
The function has also been renamed because its "chash_hash" name was
not appropriate.
Ross West reported that int32_t breaks compilation on FreeBSD. Since an
int is 32-bit on all supported platforms and we already rely on that,
change the type.
Enhance pattern convs and fetch argument parsing, now fetchs and convs callbacks used typed args.
Add more details on error messages on parsing pattern expression function.
Update existing pattern convs and fetchs to new proto.
Create stick table key type "binary".
Manage Truncation and padding if pattern's fetch-converted result don't match table key size.
MAXPATHLEN may be used at other places, it's unconvenient to have it
redefined in a few files. Also, since checking it requires including
sys/param.h, some versions of it cause a macro declaration conflict
with MIN/MAX which are defined in tools.h. The solution consists in
including sys/param.h in both files so that we ensure it's loaded
before the macros are defined and MAXPATHLEN is checked.
The introduction of a new PROXY protocol for proxied connections requires
an early analyser to decode the incoming connection and set the session
flags accordingly.
Some more work is needed, among which setting a flag on the session to
indicate it's proxied, and copying the original parameters for later
comparisons with new ACLs (eg: real_src, ...).
inetaddr_host_lim_ret() used to make use of const char** for some
args, but that make it impossible ot use char** due to the way
controls are made by gcc. So let's change that.
This option makes haproxy preserve any persistence cookie emitted by
the server, which allows the server to change it or to unset it, for
instance, after a logout request.
(cherry picked from commit 52e6d75374c7900c1fe691c5633b4ae029cae8d5)
The stats web interface must be read-only by default to prevent security
holes. As it is now allowed to enable/disable servers, a new keyword
"stats admin" is introduced to activate this admin level, conditioned by ACLs.
(cherry picked from commit 5334bab92ca7debe36df69983c19c21b6dc63f78)
Based on a patch provided by Judd Montgomery, it is now possible to
enable/disable servers from the stats web interface. This allows to select
several servers in a backend and apply the action to them at the same time.
Currently, there are 2 known limitations :
- The POST data are limited to one packet
(don't alter too many servers at a time).
- Expect: 100-continue is not supported.
(cherry picked from commit 7693948766cb5647ac03b48e782cfee2b1f14491)
If a cookie comes in with a first or last date, and they are configured on
the backend, they're checked. If a date is expired or too far in the future,
then the cookie is ignored and the specific reason appears in the cookie
field of the logs.
(cherry picked from commit faa3019107eabe6b3ab76ffec9754f2f31aa24c6)
These functions only require 5 chars to encode 30 bits, and don't expect
any padding. They will be used to encode dates in cookies.
(cherry picked from commit a7e2b5fc4612994c7b13bcb103a4a2c3ecd6438a)
The set-cookie status flags were not very handy and limited. Reorder
them to save some room for additional values and add the "U" flags
(for Updated expiration date) that will be used with expirable cookies
in insert mode.
(cherry picked from commit 5bab52f821bb0fa99fc48ad1b400769e66196ece)
We'll need one more bit to store and report the request cookie's status.
Doing this required moving a few bits around. However, now in 1.4 all bits
are used, there's no room left.
Cookie flags will need
(cherry picked from commit 09ebca0413c43620ddc375b5b4ab31a25d47b3f4)
In all cookie persistence modes but prefix, we now support cookies whose
value is suffixed with some contents after a vertical bar ('|'). This will
be used to pass an optional expiration date. So as of now we only consider
the part of the cookie value which is used before the vertical bar.
(cherry picked from commit a4486bf4e5b03b5a980d03fef799f6407b2c992d)
Add two new arguments to the "cookie" keyword, to be able to
fix a max idle and max life on them. Right now only the parameter
parsing is implemented.
(cherry picked from commit 9ad5dec4c3bb8f29129f292cb22d3fc495fcc98a)
