The principle behind speculative I/O is to speculatively try to
perform I/O before registering the events in the system. This
considerably reduces the number of calls to epoll_ctl() and
sometimes even epoll_wait(), and manages to increase overall
performance by about 10%.
The new poller has been called "sepoll". It is used by default
on Linux when it works. A corresponding option "nosepoll" and
the command line argument "-ds" allow to disable it.
Gcc provides __attribute__((constructor)) which is very convenient
to execute functions at startup right before main(). All the pollers
have been converted to have their register() function declared like
this, so that it is not necessary anymore to call them from a centralized
file.
The pollers will now be able to speculatively call the I/O
processing functions and decide whether or not they want to
poll on those FDs. The changes primarily consist in teaching
those functions how to pass the info they got an EAGAIN.
Now fdtab can contain the FD_POLL_* events so that the pollers
which can fill them can give userful information to readers and
writers about the precise condition of wakeup.
It may be dangerous to play with fdtab before doing fd_insert()
because this last one is responsible for growing maxfd as needed.
Call fd_insert() before instead.
Patch #cf83df3d162687d9c74783357421bd89f596eaac was stupid. Including
limits.h is portable and easier. At least it now builds on Solaris,
FreeBSD, Linux and OpenBSD.
Some pollers such as kqueue lose their FD across fork(), meaning that
the registered file descriptors are lost too. Now when the proxies are
started by start_proxies(), the file descriptors are not registered yet,
leaving enough time for the fork() to take place and to get a new pollfd.
It will be the first call to maintain_proxies that will register them.
FreeBSD stores INT_MIN and INT_MAX in sys/limits.h only. Other systems
(Solaris) have it in sys/types.h and do not have sys/limits.h. Let's
include sys/limits.h only if INT_MAX is not defined.
select, poll and epoll now have their dedicated functions and have
been split into distinct files. Several FD manipulation primitives
have been provided with each poller.
The rest of the code needs to be cleaned to remove traces of
StaticReadEvent/StaticWriteEvent. A trick involving a macro has
temporarily been used right now. Some work needs to be done to
factorize tests and sets everywhere.
- rewriting either the status line or request line could crash the
process due to a pointer which ought to be reset before parsing.
- rewriting the status line in the response did not work, it caused
a 502 Bad Gateway due to an erroneous state during parsing
Before calling http_parse_{sts,req}line(), it is necessary
to make msg->sol point to the beginning of the line. This
was not done, resulting in the proxy sometimes crashing when
URI rewriting or result rewriting was used.
- fix reqadd when no option httpclose is used.
- removed now unused fiprm and beprm from proxies
- split logs into two versions : TCP and HTTP
- added some docs about http headers storage and acls
- added a VIM script for syntax color highlighting (Bruno Michel)
logs are handled better with dedicated functions. The HTTP implementation
moved to proto_http.c. It has been cleaned up a bit. Now a frontend with
option httplog and no log will not call the function anymore.
The fiprm and beprm were added to ease the transition between
a single listener mode to frontends+backends. They are no longer
needed and make the code a bit more complicated. Remove them.
- fixed several bugs which might have caused a crash with bad configs
- several optimizations in header processing
- many progresses towards transaction-based processing
- option forwardfor may be used in frontends
- completed HTTP response processing
- some code refactoring between request and response processing
- new HTTP header manipulation functions
- optimizations on the recv() patch to reduce CPU usage under very
high data rates.
- more user-friendly help about the 'usesrc' keyword (CTTPROXY)
- username/groupname support from Marcus Rueckert
- added the "except" keyword to the "forwardfor" option (Bryan German)
- support for health-checks on other addresses (Fabrice Dulaunoy)
- makefile for MacOS 10.4 / Darwin (Dan Zinngrabe)
- do not insert "Connection: close" in HTTP/1.0 messages
Struct server has gathered lots of informations over the time, but
it's better for clarity and performance to group those information
by usage, the most common ones at the top and the least ones at the
bottom.
Contribution from Dan Zinngrabe :
Here is a Makefile based on that for BSD that builds HAProxy 1.3.7 on
MacOS 10.4 and Darwin. I haven't tested it extensively yet, but it
does seem to work so far.
