Summary:
In testing at tumblr, we found that using djb2 hashing instead of the
default sdbm hashing resulted is better workload distribution to our backends.
This commit implements a change, that allows the user to specify the hash
function they want to use. It does not limit itself to consistent hashing
scenarios.
The supported hash functions are sdbm (default), and djb2.
For a discussion of the feature and analysis, see mailing list thread
"Consistent hashing alternative to sdbm" :
http://marc.info/?l=haproxy&m=138213693909219
Note: This change does NOT make changes to new features, for instance,
applying an avalance hashing always being performed before applying
consistent hashing.
When trying to build with various versions of openssl, forcing the
path is still cumbersome. Let's add SSL_INC and SSL_LIB similar to
PCRE_INC and PCRE_LIB to allow forcing the path to the SSL includes
and libs.
JIT was introduced in 8.20 but it's said everywhere that it was
significantly improved in 8.32. Let's not tempt users of older
versions then. BTW the patch was developped on 8.32.
haproxy -vv shows build informations about USE flags and lib versions.
This patch introduces informations about PCRE and the new JIT feature.
It also makes USE_PCRE_JIT=1 appear in the haproxy -vv "OPTIONS".
This is useful since with the introduction of JIT we will see libpcre
related issues.
The file acl.c is a real mess, it both contains functions to parse and
process ACLs, and some sample extraction functions which act on buffers.
Some other payload analysers were arbitrarily dispatched to proto_tcp.c.
So now we're moving all payload-based fetches and ACLs to payload.c
which is capable of extracting data from buffers and rely on everything
that is protocol-independant. That way we can safely inflate this file
and only use the other ones when some fetches are really specific (eg:
HTTP, SSL, ...).
As a result of this cleanup, the following new sample fetches became
available even if they're not really useful :
always_false, always_true, rep_ssl_hello_type, rdp_cookie_cnt,
req_len, req_ssl_hello_type, req_ssl_sni, req_ssl_ver, wait_end
The function 'acl_fetch_nothing' was wrong and never used anywhere so it
was removed.
The "rdp_cookie" sample fetch used to have a mandatory argument while it
was optional in ACLs, which are supposed to iterate over RDP cookies. So
we're making it optional as a fetch too, and it will return the first one.
TCP Fast Open is supported in server mode since Linux 3.7, but current
libc's don't define TCP_FASTOPEN=23. Introduce the new USE flag USE_TFO
to define it manually in compat.h. Also note this in the TFO related
documentation.
The "osx" target may now be passed in the TARGET variable. It supports
the same features as FreeBSD and allows its users to use the GNU makefile
instead of the platform-specific makefile which lacks some features.
This allows to build haproxy for unknown targets and still have poll().
If for any reason a target does not support it, just passing USE_POLL=""
disables it.
Currently when cross-compiling, it's generally necessary to force
PCREDIR which the Makefile automatically appends /include and /lib to.
Unfortunately on most 64-bit linux distros, the lib path is instead
/lib64, which is really annoying to fix in the makefile.
So now we're computing PCRE_INC and PCRE_LIB from PCREDIR and using
these ones instead. If one wants to force paths individually, it is
possible to set them instead of setting PCREDIR. The old behaviour
of not passing anything to the compiler when PCREDIR is forced to blank
is conserved.
Currently, to reload haproxy configuration, you have to use "-sf".
There is a problem with this way of doing things. First of all, in the systemd world,
reload commands should be "oneshot" ones, which means they should not be the new main
process but rather a tool which makes a call to it and then exits. With the current approach,
the reload command is the new main command and moreover, it makes the previous one exit.
Systemd only tracks the main program, seeing it ending, it assumes it either finished or failed,
and kills everything remaining as a grabage collector. We then end up with no haproxy running
at all.
This patch adds wrapper around haproxy, no changes at all have been made into it,
so it's not intrusive and doesn't change anything for other hosts. What this wrapper does
is basically launching haproxy as a child, listen to the SIGUSR2 (not to conflict with
haproxy itself) signal, and spawing a new haproxy with "-sf" as a child to relay the
first one.
Signed-off-by: Marc-Antoine Perennou <Marc-Antoine@Perennou.com>
Versions of splice between 2.6.25 and 2.6.27.12 were bogus and would return EAGAIN
on incoming shutdowns. On these versions, we have to call recv() after such a return
in order to find whether splice is OK or not. Since 2.6.27.13 we don't need to do
this anymore, saving one useless recv() call after each splice() returning EAGAIN,
and we can avoid this logic by defining ASSUME_SPLICE_WORKS.
Building with linux2628 automatically enables splice and the flag above since the
kernel is safe. People enabling splice for custom kernels will be able to disable
this logic by hand too.
The new "cpu-map" directive allows one to assign the CPU sets that
a process is allowed to bind to. This is useful in combination with
the "nbproc" and "bind-process" directives.
The support is implicit on Linux 2.6.28 and above.
Now that all pollers make use of speculative I/O, there is no point
having two epoll implementations, so replace epoll with the sepoll code
and remove sepoll which has just become the standard epoll method.
This commit introduces HTTP compression using the zlib library.
http_response_forward_body has been modified to call the compression
functions.
This feature includes 3 algorithms: identity, gzip and deflate:
* identity: this is mostly for debugging, and it was useful for
developping the compression feature. With Content-Length in input, it
is making each chunk with the data available in the current buffer.
With chunks in input, it is rechunking, the output chunks will be
bigger or smaller depending of the size of the input chunk and the
size of the buffer. Identity does not apply any change on data.
* gzip: same as identity, but applying a gzip compression. The data
are deflated using the Z_NO_FLUSH flag in zlib. When there is no more
data in the input buffer, it flushes the data in the output buffer
(Z_SYNC_FLUSH). At the end of data, when it receives the last chunk in
input, or when there is no more data to read, it writes the end of
data with Z_FINISH and the ending chunk.
* deflate: same as gzip, but with deflate algorithm and zlib format.
Note that this algorithm has ambiguous support on many browsers and
no support at all from recent ones. It is strongly recommended not
to use it for anything else than experimentation.
You can't choose the compression ratio at the moment, it will be set to
Z_BEST_SPEED (1), as tests have shown very little benefit in terms of
compression ration when going above for HTML contents, at the cost of
a massive CPU impact.
Compression will be activated depending of the Accept-Encoding request
header. With identity, it does not take care of that header.
To build HAProxy with zlib support, use USE_ZLIB=1 in the make
parameters.
This work was initially started by David Du Colombier at Exceliance.
On Linux, accept4() does the same as accept() except that it allows
the caller to specify some flags to set on the resulting socket. We
use this to set the O_NONBLOCK flag and thus to save one fcntl()
call in each connection. The effect is a small performance gain of
around 1%.
The option is automatically enabled when target linux2628 is set, or
when the USE_ACCEPT4 Makefile variable is set. If the libc is too old
to provide the equivalent function, this is automatically detected and
our own function is used instead. In any case it is possible to force
the use of our implementation with USE_MY_ACCEPT4.
These ones are used to set the default ciphers suite on "bind" lines and
"server" lines respectively, instead of using OpenSSL's defaults. These
are probably mainly useful for distro packagers.
It removes dependencies with futex or mutex but ssl performances decrease
using nbproc > 1 because switching process force session renegotiation.
This can be useful on small systems which never intend to run in multi-process
mode.
This SSL session cache was developped at Exceliance and is the same that
was proposed for stunnel and stud. It makes use of a shared memory area
between the processes so that sessions can be handled by any process. It
is only useful when haproxy runs with nbproc > 1, but it does not hurt
performance at all with nbproc = 1. The aim is to totally replace OpenSSL's
internal cache.
The cache is optimized for Linux >= 2.6 and specifically for x86 platforms.
On Linux/x86, it makes use of futexes for inter-process locking, with some
x86 assembly for the locked instructions. On other architectures, GCC
builtins are used instead, which are available starting from gcc 4.1.
On other operating systems, the locks fall back to pthread mutexes so
libpthread is automatically linked. It is not recommended since pthreads
are much slower than futexes. The lib is only linked if SSL is enabled.
When this flag is set, the SSL data layer is enabled.
At the moment, only the GNU makefile was touched, the other ones
make the option handling a bit tricky.
The "raw_sock" prefix will be more convenient for naming functions as
it will be prefixed with the data layer and suffixed with the data
direction. So let's rename the files now to avoid any further confusion.
The #include directive was also removed from a number of files which do
not need it anymore.
This feature relies on GCC's ability to call helpers at function entry/exit
points. We define these helpers to quickly dump the minimum info into a trace
file that can be converted to a human readable format using a script in the
contrib/trace directory. This has only been implemented in the GNU makefile
for now on as it is unsure whether it's supported on all OSes.
The feature is enabled by building with "TRACE=1". The performance impact is
huge, so this feature should only be used when debugging. To limit the loss
of performance, fprintf() has been disabled and the output is hand-crafted
and emitted using fwrite(), resulting in doubling the performance. Using the
TSC instead of gettimeofday() also doubles the performance. Around 1200 conns/s
may be achieved on a Pentium-M 1.7 GHz which leads to around 50 MB/s of traces.
The entry and exits of all functions will be dumped into a file designated
by the HAPROXY_TRACE environment variable, or by default "trace.out". If the
trace file name is empty or "/dev/null", then traces are disabled. If
opening the trace file fails, then stderr is used. If HAPROXY_TRACE_FAST is
used, then the time is taken from the global <now> variable. Last, if
HAPROXY_TRACE_TSC is used, then the machine's TSC is used instead of the
real time (almost twice as fast).
The output format is :
<sec.usec> <level> <caller_ptr> <dir> <callee_ptr>
or :
<tsc> <level> <caller_ptr> <dir> <callee_ptr>
where <dir> is '>' when entering a function and '<' when leaving.
The awk script in contrib/trace provides a nicer indented output :
6f74989e6f8 ->->-> run_poll_loop > signal_process_queue [src/haproxy.c:1097:0x804bd69] > [include/proto/signal.h:32:0x8049cd0]
6f74989eb00 run_poll_loop < signal_process_queue [src/haproxy.c:1097:0x804bd69] < [include/proto/signal.h:32:0x8049cd0]
6f74989ef44 ->->-> run_poll_loop > wake_expired_tasks [src/haproxy.c:1100:0x804bd72] > [src/task.c:123:0x8055060]
6f74989f3a6 ->->->-> wake_expired_tasks > eb32_lookup_ge [src/task.c:128:0x8055091] > [ebtree/eb32tree.c:138:0x80a8c70]
6f74989f7e9 wake_expired_tasks < eb32_lookup_ge [src/task.c:128:0x8055091] < [ebtree/eb32tree.c:138:0x80a8c70]
6f74989fc0d ->->->-> wake_expired_tasks > eb32_first [src/task.c:134:0x80550d5] > [ebtree/eb32tree.h:55:0x8054ad0]
6f7498a003d ->->->->-> eb32_first > eb_first [ebtree/eb32tree.h:56:0x8054af1] > [ebtree/ebtree.h:520:0x8054a10]
6f7498a0436 ->->->->->-> eb_first > eb_walk_down [ebtree/ebtree.h:521:0x8054a33] > [ebtree/ebtree.h:442:0x80549a0]
6f7498a0843 ->->->->->->-> eb_walk_down > eb_gettag [ebtree/ebtree.h:445:0x80549d6] > [ebtree/ebtree.h:418:0x80548e0]
6f7498a0c2b eb_walk_down < eb_gettag [ebtree/ebtree.h:445:0x80549d6] < [ebtree/ebtree.h:418:0x80548e0]
6f7498a1042 ->->->->->->-> eb_walk_down > eb_untag [ebtree/ebtree.h:447:0x80549e2] > [ebtree/ebtree.h:412:0x80548a0]
6f7498a1498 eb_walk_down < eb_untag [ebtree/ebtree.h:447:0x80549e2] < [ebtree/ebtree.h:412:0x80548a0]
6f7498a18c6 ->->->->->->-> eb_walk_down > eb_root_to_node [ebtree/ebtree.h:448:0x80549e7] > [ebtree/ebtree.h:432:0x8054960]
6f7498a1cd4 eb_walk_down < eb_root_to_node [ebtree/ebtree.h:448:0x80549e7] < [ebtree/ebtree.h:432:0x8054960]
6f7498a20c4 eb_first < eb_walk_down [ebtree/ebtree.h:521:0x8054a33] < [ebtree/ebtree.h:442:0x80549a0]
6f7498a24b4 eb32_first < eb_first [ebtree/eb32tree.h:56:0x8054af1] < [ebtree/ebtree.h:520:0x8054a10]
6f7498a289c wake_expired_tasks < eb32_first [src/task.c:134:0x80550d5] < [ebtree/eb32tree.h:55:0x8054ad0]
6f7498a2c8c run_poll_loop < wake_expired_tasks [src/haproxy.c:1100:0x804bd72] < [src/task.c:123:0x8055060]
6f7498a3095 ->->-> run_poll_loop > process_runnable_tasks [src/haproxy.c:1103:0x804bd7a] > [src/task.c:190:0x8055150]
A nice improvement would possibly consist in trying to get the function's
arguments in the stack and to dump a few more infor for some well-known
functions (eg: the session's status for process_session).
We'll soon have an SSL socket layer, and in order to ease the difference
between the two, we use the name "sock_raw" to designate the one which
directly talks to the sockets without any conversion.
make_arg_list() builds an array of typed arguments with their values,
that the caller describes how to parse. This will be used to support
multiple arguments for ACLs and patterns, which is currently problematic
and prevents ACLs and patterns from being merged. Up to 7 arguments types
may be enumerated in a single 32-bit word, including their number of
mandatory parts.
At the moment, these files are not used yet, they're only built. Note that
the 4-bit encoding for the type has left only one unused type!
The principle behind this load balancing algorithm was first imagined
and modeled by Steen Larsen then iteratively refined through several
work sessions until it would totally address its original goal.
The purpose of this algorithm is to always use the smallest number of
servers so that extra servers can be powered off during non-intensive
hours. Additional tools may be used to do that work, possibly by
locally monitoring the servers' activity.
The first server with available connection slots receives the connection.
The servers are choosen from the lowest numeric identifier to the highest
(see server parameter "id"), which defaults to the server's position in
the farm. Once a server reaches its maxconn value, the next server is used.
It does not make sense to use this algorithm without setting maxconn. Note
that it can however make sense to use minconn so that servers are not used
at full load before starting new servers, and so that introduction of new
servers requires a progressively increasing load (the number of servers
would more or less follow the square root of the load until maxconn is
reached). This algorithm ignores the server weight, and is more beneficial
to long sessions such as RDP or IMAP than HTTP, though it can be useful
there too.
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.
Gcc 4.4 enables strict aliasing by default, resuling in complaints
when casting struct sockaddr_storage to sockaddr_in. Not only doing
this does not provide any noticeable performance improvement, it also
presents a risk of strange bugs even when the compiler does not emit
a warning, so let's disable this optimization !
Hank A. Paulson suggested to add CPU=native to optimize the code for
the build machine. This makes sense in a lot of situations. Since it
is often possible to have both 32 and 64 bits supported on recent
systems, the ARCH=32 and ARCH=64 build options were also added.
Some distros' libc are built for CPUs earlier than i686 and as such do
not offer support for Linux kernel's faster vsyscalls. This code adds
a new build option USE_VSYSCALLS to bypass libc for most commonly used
system calls. A net gain of about 10% can be observed with this change
alone.
It only works when /proc/sys/abi/vsyscall32 equals exactly 2. When it's
set to 1, the VDSO is randomized and cannot be used.
The 'client.c' file now only contained frontend-specific functions,
so it has naturally be renamed 'frontend.c'. Same for client.h. This
has also been an opportunity to remove some cross references from
files that should not have depended on it.
In the end, this file should contain a protocol-agnostic accept()
code, which would initialize a session, task, etc... based on an
accept() from a lower layer. Right now there are still references
to TCP.
Holger Just and Ross West reported build issues on FreeBSD and
Solaris that were initially caused by the definition of
_XOPEN_SOURCE at the top of auth.c, which was required on Linux
to avoid a build warning.
Krzysztof Oledzki found that using _GNU_SOURCE instead also worked
on Linux and did not cause any issue on several versions of FreeBSD.
Solaris still reported a warning this time, which was fixed by
including <crypt.h>, which itself is not present on FreeBSD nor on
all Linux toolchains.
So by adding a new build option (NEED_CRYPT_H), we can get Solaris
to get crypt() working and stop complaining at the same time, without
impacting other platforms.
This fix was tested at least on several linux toolchains (at least
uclibc, glibc 2.2.5, 2.3.6 and 2.7), on FreeBSD 4 to 8, Solaris 8
(which needs crypt.h), and AIX 5.3 (without crypt.h).
Every time it builds without a warning.
Add generic authentication & authorization support.
Groups are implemented as bitmaps so the count is limited to
sizeof(int)*8 == 32.
Encrypted passwords are supported with libcrypt and crypt(3), so it is
possible to use any method supported by your system. For example modern
Linux/glibc instalations support MD5/SHA-256/SHA-512 and of course classic,
DES-based encryption.
