When a very large number of servers is configured (thousands),
shutting down many of them at once could lead to large number
of calls to recalc_server_map() which already takes some time.
This would result in an O(N^3) computation time, leading to
noticeable pauses on slow embedded CPUs on test platforms.
Instead, mark the map as dirty and recalc it only when needed.
- acl: smarter integer comparison support in ACLs
- acl: specify the direction during fetches
- acl: provide the argument length for fetch functions
- acl: provide a reference to the expr to fetch()
- acl: implement matching on header values
- acl: support maching on 'path' component
- acl: permit to return any header when no name specified
- errorfile: use a local file to feed error messages
- negation in ACL conds was not cleared between terms
- fix segfault at exit when using captures
- improve memory freeing upon exit
- acl: support '-i' to ignore case when matching
- str2net() must not change the const char *
- provide default ACLs
- acl: distinguish between request and response headers
- added the 'use_backend' keyword for full content-switching
- acl: added the TRUE and FALSE ACLs.
- shut warnings 'is*' macros from ctype.h on solaris
Those ACLs are sometimes useful for troubleshooting. Two ACL subjects
"always_true" and "always_false" have been added too. They return what
their subject says for every pattern. Also, acl_match_pst() has been
removed.
The new "use_backend" keyword permits full content switching by the
use of ACLs. Its usage is simple :
use_backend <backend_name> {if|unless} <acl_cond>
Implemented the "-i" option on ACLs to state that the matching
will have to be performed for all patterns ignoring case. The
usage is :
acl <aclname> <aclsubject> -i pattern1 ...
If a pattern must begin with "-", either it must not be the first one,
or the "--" option should be specified first.
hdr(x), hdr_reg(x), hdr_beg(x), hdr_end(x), hdr_sub(x), hdr_dir(x),
hdr_dom(x), hdr_cnt(x) and hdr_val(x) have been implemented. They
apply to any of the possibly multiple values of header <x>.
Right now, hdr_val() is limited to integer matching, but it should
reasonably be upgraded to match long long ints.
Some fetches such as 'line' or 'hdr' need to know the direction of
the test (request or response). A new 'dir' parameter is now
propagated from the caller to achieve this.
ACLs now support operators such as 'eq', 'le', 'lt', 'ge' and 'gt'
in order to give more flexibility to the language. Because of this
change, the 'dst_limit' keyword changed to 'dst_conn' and now requires
either a range or a test such as 'dst_conn lt 1000' which is more
understandable.
- do not re-arm read timeout in SHUTR state
- optimize I/O by detecting system starvation
- the epoll FD must not be shared between processes
- limit the number of events returned by *poll*
By default, epoll/kqueue used to return as many events as possible.
This could sometimes cause huge latencies (latencies of up to 400 ms
have been observed with many thousands of fds at once). Limiting the
number of events returned also reduces the latency by avoiding too
many blind processing. The value is set to 200 by default and can be
changed in the global section using the tune.maxpollevents parameter.
A second occurrence of read-timeout rearming was present in stream_sock.c.
To fix the problem, it was necessary to put the shutdown information in
the buffer (already planned).
- fixed ev_sepoll again by rewriting the state machine
- switched all timeouts to timevals instead of milliseconds
- improved memory management using mempools v2.
- several minor optimizations
When we're interrupted by another instance, it is very likely
that the other one will need some memory. Now we know how to
free what is not used, so let's do it.
Also only free non-null pointers. Previously, pool_destroy()
did implicitly check for this case which was incidentely
needed.
- keep the number of users of each pool
- call the garbage collector on out of memory conditions
- sort the pools by size for faster creation
- force the alignment size to 16 bytes instead of 4*sizeof(void *)
Also during this process, a bug was found in appsession_refresh().
It would not automatically requeue the task in the queue, so the
old sessions would not vanish.
The timeout functions were difficult to manipulate because they were
rounding results to the millisecond. Thus, it was difficult to compare
and to check what expired and what did not. Also, the comparison
functions were heavy with multiplies and divides by 1000. Now, all
timeouts are stored in timevals, reducing the number of operations
for updates and leading to cleaner and more efficient code.
- several fixes in ev_sepoll
- fixed some expiration dates on some tasks
- fixed a bug in connection establishment detection due to speculative I/O
- fixed rare bug occuring on TCP with early close (reported by Andy Smith)
- implemented URI hashing algorithm (Guillaume Dallaire)
- implemented SMTP health checks (Peter van Dijk)
- replaced the rbtree with ul2tree from old scheduler project
- new framework for generic ACL support
- added the 'acl' and 'block' keywords to the config language
- added several ACL criteria and matches (IP, port, URI, ...)
- cleaned up and better modularization for some time functions
- fixed list macros
- fixed useless memory allocation in str2net()
- store the original destination address in the session
Peter van Dijk contributed this patch which implements the "smtpchk"
option, which is to SMTP what "httpchk" is to HTTP. By default, it sends
"HELO localhost" to the servers, and waits for the 250 message, but it
can also send a specific request.
The new 'block' keyword makes it possible to block a request based on
ACL test results. Block accepts two optional arguments : 'if' <cond>
and 'unless' <cond>.
The request will be blocked with a 403 response if the condition is validated
(if) or if it is not (unless). Do not rely on this one too much, as it's more
of a proof of concept helping in developing other matches.
This framework offers all other subsystems the ability to register
ACL matching criteria. Some generic matching functions are already
provided. Others will come soon and the framework shall evolve.
There are multiple places where the client's destination address is
required. Let's store it in the session when needed, and add a flag
to inform that it has been retrieved.
