This macro should be used to declare variables or struct members depending on
the USE_THREAD compile option. It avoids the encapsulation of such declarations
between #ifdef/#endif. It is used to declare all lock variables.
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.
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.
Make it so for each server, instead of specifying a hostname, one can use
a SRV label.
When doing so, haproxy will first resolve the SRV label, then use the
resulting hostnames, as well as port and weight (priority is ignored right
now), to each server using the SRV label.
It is resolved periodically, and any server disappearing from the SRV records
will be removed, and any server appearing will be added, assuming there're
free servers in haproxy.
This adds a new "dynamic" keyword for the cookie option. If set, a cookie
will be generated for each server (assuming one isn't already provided on
the "server" line), from the IP of the server, the TCP port, and a secret
key provided. To provide the secret key, a new keyword as been added,
"dynamic-cookie-key", for backends.
Example :
backend bk_web
balance roundrobin
dynamic-cookie-key "bla"
cookie WEBSRV insert dynamic
server s1 127.0.0.1:80 check
server s2 192.168.56.1:80 check
This is a first step to be able to dynamically add and remove servers,
without modifying the configuration file, and still have all the load
balancers redirect the traffic to the right server.
Provide a way to generate session cookies, based on the IP address of the
server, the TCP port, and a secret key provided.
The previous version used an O(number of proxies)^2 algo to get the sum of
the number of maxconns of frontends which reference a backend at least once.
This new version adds the frontend's maxconn number to the backend's
struct proxy member 'tot_fe_maxconn' when the backend name is resolved
for switching rules or default_backend statment. At the end, the final
backend's fullconn is computed looping only one time for all on proxies O(n).
The load of a configuration using a large amount of backends (10 thousands)
without configured fullconn was reduced from several minutes to few seconds.
We used to have 3 types of counters with a huge overlap :
- listener counters : stats collected for each bind line
- proxy counters : union of the frontend and backend counters
- server counters : stats collected per server
It happens that quite a good part was common between listeners and
proxies due to the frontend counters being updated at the two locations,
and that similarly the server and proxy counters were overlapping and
being updated together.
This patch cleans this up to propose only two types of counters :
- fe_counters: used by frontends and listeners, related to
incoming connections activity
- be_counters: used by backends and servers, related to outgoing
connections activity
This allowed to remove some non-sensical counters from both parts. For
frontends, the following entries were removed :
cum_lbconn, last_sess, nbpend_max, failed_conns, failed_resp,
retries, redispatches, q_time, c_time, d_time, t_time
For backends, this ones was removed : intercepted_req.
While doing this it was discovered that we used to incorrectly report
intercepted_req for backends in the HTML stats, which was always zero
since it's never updated.
Also it revealed a few inconsistencies (which were not fixed as they
are harmless). For example, backends count connections (cum_conn)
instead of sessions while servers count sessions and not connections.
Over the long term, some extra cleanups may be performed by having
some counters update functions touching both the server and backend
at the same time, as well as both the frontend and listener, to
ensure that all sides have all their stats properly filled. The stats
dump will also be able to factor the dump functions by counter types.
A new "option spop-check" statement has been added to enable server health
checks based on SPOP HELLO handshake. SPOP is the protocol used by SPOE filters
to talk to servers.
This commit introduces "tcp-request session" rules. These are very
much like "tcp-request connection" rules except that they're processed
after the handshake, so it is possible to consider SSL information and
addresses rewritten by the proxy protocol header in actions. This is
particularly useful to track proxied sources as this was not possible
before, given that tcp-request content rules are processed after each
HTTP request. Similarly it is possible to assign the proxied source
address or the client's cert to a variable.
There are two issues with error captures. The first one is that the
capture size is still hard-coded to BUFSIZE regardless of any possible
tune.bufsize setting and of the fact that frontends only capture request
errors and that backends only capture response errors. The second is that
captures are allocated in both directions for all proxies, which start to
count a lot in configs using thousands of proxies.
This patch changes this so that error captures are allocated only when
needed, and of the proper size. It also refrains from dumping a buffer
that was not allocated, which still allows to emit all relevant info
such as flags and HTTP states. This way it is possible to save up to
32 kB of RAM per proxy in the default configuration.
Now, filter's configuration (.id, .conf and .ops fields) is stored in the
structure 'flt_conf'. So proxies own a flt_conf list instead of a filter
list. When a filter is attached to a stream, it gets a pointer on its
configuration. This avoids mixing the filter's context (owns by a stream) and
its configuration (owns by a proxy). It also saves 2 pointers per filter
instance.
This patch adds the support of filters in HAProxy. The main idea is to have a
way to "easely" extend HAProxy by adding some "modules", called filters, that
will be able to change HAProxy behavior in a programmatic way.
To do so, many entry points has been added in code to let filters to hook up to
different steps of the processing. A filter must define a flt_ops sutrctures
(see include/types/filters.h for details). This structure contains all available
callbacks that a filter can define:
struct flt_ops {
/*
* Callbacks to manage the filter lifecycle
*/
int (*init) (struct proxy *p);
void (*deinit)(struct proxy *p);
int (*check) (struct proxy *p);
/*
* Stream callbacks
*/
void (*stream_start) (struct stream *s);
void (*stream_accept) (struct stream *s);
void (*session_establish)(struct stream *s);
void (*stream_stop) (struct stream *s);
/*
* HTTP callbacks
*/
int (*http_start) (struct stream *s, struct http_msg *msg);
int (*http_start_body) (struct stream *s, struct http_msg *msg);
int (*http_start_chunk) (struct stream *s, struct http_msg *msg);
int (*http_data) (struct stream *s, struct http_msg *msg);
int (*http_last_chunk) (struct stream *s, struct http_msg *msg);
int (*http_end_chunk) (struct stream *s, struct http_msg *msg);
int (*http_chunk_trailers)(struct stream *s, struct http_msg *msg);
int (*http_end_body) (struct stream *s, struct http_msg *msg);
void (*http_end) (struct stream *s, struct http_msg *msg);
void (*http_reset) (struct stream *s, struct http_msg *msg);
int (*http_pre_process) (struct stream *s, struct http_msg *msg);
int (*http_post_process) (struct stream *s, struct http_msg *msg);
void (*http_reply) (struct stream *s, short status,
const struct chunk *msg);
};
To declare and use a filter, in the configuration, the "filter" keyword must be
used in a listener/frontend section:
frontend test
...
filter <FILTER-NAME> [OPTIONS...]
The filter referenced by the <FILTER-NAME> must declare a configuration parser
on its own name to fill flt_ops and filter_conf field in the proxy's
structure. An exemple will be provided later to make it perfectly clear.
For now, filters cannot be used in backend section. But this is only a matter of
time. Documentation will also be added later. This is the first commit of a long
list about filters.
It is possible to have several filters on the same listener/frontend. These
filters are stored in an array of at most MAX_FILTERS elements (define in
include/types/filters.h). Again, this will be replaced later by a list of
filters.
The filter API has been highly refactored. Main changes are:
* Now, HA supports an infinite number of filters per proxy. To do so, filters
are stored in list.
* Because filters are stored in list, filters state has been moved from the
channel structure to the filter structure. This is cleaner because there is no
more info about filters in channel structure.
* It is possible to defined filters on backends only. For such filters,
stream_start/stream_stop callbacks are not called. Of course, it is possible
to mix frontend and backend filters.
* Now, TCP streams are also filtered. All callbacks without the 'http_' prefix
are called for all kind of streams. In addition, 2 new callbacks were added to
filter data exchanged through a TCP stream:
- tcp_data: it is called when new data are available or when old unprocessed
data are still waiting.
- tcp_forward_data: it is called when some data can be consumed.
* New callbacks attached to channel were added:
- channel_start_analyze: it is called when a filter is ready to process data
exchanged through a channel. 2 new analyzers (a frontend and a backend)
are attached to channels to call this callback. For a frontend filter, it
is called before any other analyzer. For a backend filter, it is called
when a backend is attached to a stream. So some processing cannot be
filtered in that case.
- channel_analyze: it is called before each analyzer attached to a channel,
expects analyzers responsible for data sending.
- channel_end_analyze: it is called when all other analyzers have finished
their processing. A new analyzers is attached to channels to call this
callback. For a TCP stream, this is always the last one called. For a HTTP
one, the callback is called when a request/response ends, so it is called
one time for each request/response.
* 'session_established' callback has been removed. Everything that is done in
this callback can be handled by 'channel_start_analyze' on the response
channel.
* 'http_pre_process' and 'http_post_process' callbacks have been replaced by
'channel_analyze'.
* 'http_start' callback has been replaced by 'http_headers'. This new one is
called just before headers sending and parsing of the body.
* 'http_end' callback has been replaced by 'channel_end_analyze'.
* It is possible to set a forwarder for TCP channels. It was already possible to
do it for HTTP ones.
* Forwarders can partially consumed forwardable data. For this reason a new
HTTP message state was added before HTTP_MSG_DONE : HTTP_MSG_ENDING.
Now all filters can define corresponding callbacks (http_forward_data
and tcp_forward_data). Each filter owns 2 offsets relative to buf->p, next and
forward, to track, respectively, input data already parsed but not forwarded yet
by the filter and parsed data considered as forwarded by the filter. A any time,
we have the warranty that a filter cannot parse or forward more input than
previous ones. And, of course, it cannot forward more input than it has
parsed. 2 macros has been added to retrieve these offets: FLT_NXT and FLT_FWD.
In addition, 2 functions has been added to change the 'next size' and the
'forward size' of a filter. When a filter parses input data, it can alter these
data, so the size of these data can vary. This action has an effet on all
previous filters that must be handled. To do so, the function
'filter_change_next_size' must be called, passing the size variation. In the
same spirit, if a filter alter forwarded data, it must call the function
'filter_change_forward_size'. 'filter_change_next_size' can be called in
'http_data' and 'tcp_data' callbacks and only these ones. And
'filter_change_forward_size' can be called in 'http_forward_data' and
'tcp_forward_data' callbacks and only these ones. The data changes are the
filter responsability, but with some limitation. It must not change already
parsed/forwarded data or data that previous filters have not parsed/forwarded
yet.
Because filters can be used on backends, when we the backend is set for a
stream, we add filters defined for this backend in the filter list of the
stream. But we must only do that when the backend and the frontend of the stream
are not the same. Else same filters are added a second time leading to undefined
behavior.
The HTTP compression code had to be moved.
So it simplifies http_response_forward_body function. To do so, the way the data
are forwarded has changed. Now, a filter (and only one) can forward data. In a
commit to come, this limitation will be removed to let all filters take part to
data forwarding. There are 2 new functions that filters should use to deal with
this feature:
* flt_set_http_data_forwarder: This function sets the filter (using its id)
that will forward data for the specified HTTP message. It is possible if it
was not already set by another filter _AND_ if no data was yet forwarded
(msg->msg_state <= HTTP_MSG_BODY). It returns -1 if an error occurs.
* flt_http_data_forwarder: This function returns the filter id that will
forward data for the specified HTTP message. If there is no forwarder set, it
returns -1.
When an HTTP data forwarder is set for the response, the HTTP compression is
disabled. Of course, this is not definitive.
Michael Ezzell reported a bug causing haproxy to segfault during startup
when trying to send syslog message from Lua. The function __send_log() can
be called with *p that is NULL and/or when the configuration is not fully
parsed, as is the case with Lua.
This patch fixes this problem by using individual vectors instead of the
pre-generated strings log_htp and log_htp_rfc5424.
Also, this patch fixes a problem causing haproxy to write the wrong pid in
the logs -- the log_htp(_rfc5424) strings were generated at the haproxy
start, but "pid" value would be changed after haproxy is started in
daemon/systemd mode.
This patch adds a new RFC5424-specific log-format for the structured-data
that is automatically send by __send_log() when the sender is in RFC5424
mode.
A new statement "log-format-sd" should be used in order to set log-format
for the structured-data part in RFC5424 formatted syslog messages.
Example:
log-format-sd [exampleSDID@1234\ bytes=\"%B\"\ status=\"%ST\"]
The function __send_log() iterates over senders and passes the header as
the first vector to sendmsg(), thus it can send a logger-specific header
in each message.
A new logger arguments "format rfc5424" should be used in order to enable
RFC5424 header format. For example:
log 10.2.3.4:1234 len 2048 format rfc5424 local2 info
At the moment we have to call snprintf() for every log line just to
rebuild a constant. Thanks to sendmsg(), we send the message in 3 parts:
time-based header, proxy-specific hostname+log-tag+pid, session-specific
message.
This directive gives HAProxy the ability to use the either the global
server-state-file directive or a local one using server-state-file-name to
load server states.
The state can be saved right before the reload by the init script, using
the "show servers state" command on the stats socket redirecting output into
a file.
For now it only supports "never", meaning that we never want to reuse a
shared connection, and "always", meaning that we can use any connection
that was not marked private. When "never" is set, this also implies that
no idle connection may become a shared one.
function proxy_find_best_match can update the caller by updating an int
provided in argument.
For now, proxy_find_best_match hardcode bit values 0x01, 0x02 and 0x04,
which is not understandable when reading a code exploiting them.
This patch defines 3 macros with a more explicit wording, so further
reading of a code exploiting the magic bit values will be understandable
more easily.
For backend load balancing it sometimes makes sense to redispatch rather
than retrying against the same server. For example, when machines or routers
fail you may not want to waste time retrying against a dead server and
would instead prefer to immediately redispatch against other servers.
This patch allows backend sections to specify that they want to
redispatch on a particular interval. If the interval N is positive the
redispatch occurs on every Nth retry, and if the interval N is negative then
the redispatch occurs on the Nth retry prior to the last retry (-1 is the
default and maintains backwards compatibility). In low latency environments
tuning this setting can save a few hundred milliseconds when backends fail.
It is sometimes desirable to wait for the body of an HTTP request before
taking a decision. This is what is being done by "balance url_param" for
example. The first use case is to buffer requests from slow clients before
connecting to the server. Another use case consists in taking the routing
decision based on the request body's contents. This option placed in a
frontend or backend forces the HTTP processing to wait until either the whole
body is received, or the request buffer is full, or the first chunk is
complete in case of chunked encoding. It can have undesired side effects with
some applications abusing HTTP by expecting unbufferred transmissions between
the frontend and the backend, so this should definitely not be used by
default.
Note that it would not work for the response because we don't reset the
message state before starting to forward. For the response we need to
1) reset the message state to MSG_100_SENT or BODY , and 2) to reset
body_len in case of chunked encoding to avoid counting it twice.
Recently some browsers started to implement a "pre-connect" feature
consisting in speculatively connecting to some recently visited web sites
just in case the user would like to visit them. This results in many
connections being established to web sites, which end up in 408 Request
Timeout if the timeout strikes first, or 400 Bad Request when the browser
decides to close them first. These ones pollute the log and feed the error
counters. There was already "option dontlognull" but it's insufficient in
this case. Instead, this option does the following things :
- prevent any 400/408 message from being sent to the client if nothing
was received over a connection before it was closed ;
- prevent any log from being emitted in this situation ;
- prevent any error counter from being incremented
That way the empty connection is silently ignored. Note that it is better
not to use this unless it is clear that it is needed, because it will hide
real problems. The most common reason for not receiving a request and seeing
a 408 is due to an MTU inconsistency between the client and an intermediary
element such as a VPN, which blocks too large packets. These issues are
generally seen with POST requests as well as GET with large cookies. The logs
are often the only way to detect them.
This patch should be backported to 1.5 since it avoids false alerts and
makes it easier to monitor haproxy's status.
With HTTP/2, we'll have to support multiplexed streams. A stream is in
fact the largest part of what we currently call a session, it has buffers,
logs, etc.
In order to catch any error, this commit removes any reference to the
struct session and tries to rename most "session" occurrences in function
names to "stream" and "sess" to "strm" when that's related to a session.
The files stream.{c,h} were added and session.{c,h} removed.
The session will be reintroduced later and a few parts of the stream
will progressively be moved overthere. It will more or less contain
only what we need in an embryonic session.
Sample fetch functions and converters will have to change a bit so
that they'll use an L5 (session) instead of what's currently called
"L4" which is in fact L6 for now.
Once all changes are completed, we should see approximately this :
L7 - http_txn
L6 - stream
L5 - session
L4 - connection | applet
There will be at most one http_txn per stream, and a same session will
possibly be referenced by multiple streams. A connection will point to
a session and to a stream. The session will hold all the information
we need to keep even when we don't yet have a stream.
Some more cleanup is needed because some code was already far from
being clean. The server queue management still refers to sessions at
many places while comments talk about connections. This will have to
be cleaned up once we have a server-side connection pool manager.
Stream flags "SN_*" still need to be renamed, it doesn't seem like
any of them will need to move to the session.
Some services such as peers and CLI pre-set the target applet immediately
during accept(), and for this reason they're forced to have a dedicated
accept() function which does not even properly follow everything the regular
one does (eg: sndbuf/rcvbuf/linger/nodelay are not set, etc).
Let's store the default target when known into the frontend's config so that
it's session_accept() which automatically sets it.
These modifications are done for resolving cross-dependent
includes in the upcoming LUA code.
<proto/channel.h> misses <types/channel.h>.
<types/acl.h> doesn't use <types/session.h> because the session
is already declared in the file as undefined pointer.
appsession.c misses <unistd.h> to use "write()".
Declare undefined pointer "struct session" for <types/proxy.h>
and <types/queue.h>. These includes dont need the detail of this
struct.
This patch adds a new option which allows configuration of the maximum
log level of messages for which email alerts will be sent.
The default is alert which is more restrictive than
the current code which sends email alerts for all priorities.
That behaviour may be configured using the new configuration
option to set the maximum level to notice or greater.
email-alert level notice
Signed-off-by: Simon Horman <horms@verge.net.au>
This currently does nothing beyond parsing the configuration
and storing in the proxy as there is no implementation of email alerts.
Signed-off-by: Simon Horman <horms@verge.net.au>
This is equivalent to what was done in commit 48936af ("[MINOR] log:
ability to override the syslog tag") but this time instead of doing
this globally, it does it per proxy. The purpose is to be able to use
a separate log tag for various proxies (eg: make it easier to route
log messages depending on the customer).
Sometimes it would be convenient to have a log counter so that from a log
server we know whether some logs were lost or not. The frontend's log counter
serves exactly this purpose. It's incremented each time a traffic log is
produced. If a log is disabled using "http-request set-log-level silent",
the counter will not be incremented. However, admin logs are not accounted
for. Also, if logs are filtered out before being sent to the server because
of a minimum level set on the log line, the counter will be increased anyway.
The counter is 32-bit, so it will wrap, but that's not an issue considering
that 4 billion logs are rarely in the same file, let alone close to each
other.
Just by moving a few struct members around, we can avoid 32-bit holes
between 64-bit pointers and shrink the struct size by 48 bytes. That's
not huge but that's for free, so let's do it.
This patch remove all references of standard regex in haproxy. The last
remaining references are only in the regex.[ch] files.
In the file src/checks.c, the original function uses a "pmatch" array.
In fact this array is unused. This patch remove it.
Long-lived sessions are often subject to half-closed sessions resulting in
a lot of sessions appearing in FIN_WAIT state in the system tables, and no
way for haproxy to get rid of them. This typically happens because clients
suddenly disconnect without sending any packet (eg: FIN or RST was lost in
the path), and while the server detects this using an applicative heart
beat, haproxy does not close the connection.
This patch adds two new timeouts : "timeout client-fin" and
"timeout server-fin". The former allows one to override the client-facing
timeout when a FIN has been received or sent. The latter does the same for
server-facing connections, which is less useful.
Some consistency checks cannot be performed between frontends, backends
and peers at the moment because there is no way to check for intersection
between processes bound to some processes when the number of processes is
higher than the number of bits in a word.
So first, let's limit the number of processes to the machine's word size.
This means nbproc will be limited to 32 on 32-bit machines and 64 on 64-bit
machines. This is far more than enough considering that configs rarely go
above 16 processes due to scalability and management issues, so 32 or 64
should be fine.
This way we'll ensure we can always build a mask of all the processes a
section is bound to.
Finn Arne Gangstad suggested that we should have the ability to break
keep-alive when the target server has reached its maxconn and that a
number of connections are present in the queue. After some discussion
around his proposed patch, the following solution was suggested : have
a per-proxy setting to fix a limit to the number of queued connections
on a server after which we break keep-alive. This ensures that even in
high latency networks where keep-alive is beneficial, we try to find a
different server.
This patch is partially based on his original proposal and implements
this configurable threshold.
This is the continuation of previous patch. Now that full buffers are
not rejected anymore, let's wait for at least the advertised chunk or
body length to be present or the buffer to be full. When either
condition is met, the message processing can go forward.
Thus we don't need to use url_param_post_limit anymore, which was passed
in the configuration as an optionnal <max_wait> parameter after the
"check_post" value. This setting was necessary when the feature was
implemented because there was no support for parsing message bodies.
The argument is now silently ignored if set in the configuration.
We have a use case where we look up a customer ID in an HTTP header
and direct it to the corresponding server. This can easily be done
using ACLs and use_backend rules, but the configuration becomes
painful to maintain when the number of customers grows to a few
tens or even a several hundreds.
We realized it would be nice if we could make the use_backend
resolve its name at run time instead of config parsing time, and
use a similar expression as http-request add-header to decide on
the proper backend to use. This permits the use of prefixes or
even complex names in backend expressions. If no name matches,
then the default backend is used. Doing so allowed us to get rid
of all the use_backend rules.
Since there are some config checks on the use_backend rules to see
if the referenced backend exists, we want to keep them to detect
config errors in normal config. So this patch does not modify the
default behaviour and proceeds this way :
- if the backend name in the use_backend directive parses as a log
format rule, it's used as-is and is resolved at run time ;
- otherwise it's a static name which must be valid at config time.
There was the possibility of doing this with the use-server directive
instead of use_backend, but it seems like use_backend is more suited
to this task, as it can be used for other purposes. For example, it
becomes easy to serve a customer-specific proxy.pac file based on the
customer ID by abusing the errorfile primitive :
use_backend bk_cust_%[hdr(X-Cust-Id)] if { hdr(X-Cust-Id) -m found }
default_backend bk_err_404
backend bk_cust_1
errorfile 200 /etc/haproxy/static/proxy.pac.cust1
Signed-off-by: Bertrand Jacquin <bjacquin@exosec.fr>
Large configurations can take time to parse when thousands of backends
are in use. Let's store all the proxies in trees.
findproxy_mode() has been modified to use the tree for lookups, which
has divided the parsing time by about 2.5. But many lookups are still
present at many places and need to be dealt with.
A new tcp-check rule type: connect.
It allows HAProxy to test applications which stand on multiple ports or
multiple applications load-balanced through the same backend.
Since we support HTTP keep-alive, there is no more reason for staying
in tunnel mode by default. It is confusing for new users and creates
more issues than it solves. Option "http-tunnel" is available to force
to use it if really desired.
Switching to KA by default has implied to change the value of some
option flags and some transaction flags so that value zero (default)
matches keep-alive. That explains why more code has been changed than
expected. Tests have been run on the 25 combinations of frontend and
backend options, plus a few with option http-pretend-keepalive, and
no anomaly was found.
The relation between frontend and backends remains the same. Options
have been updated to take precedence over http-keep-alive which is now
implicit.
All references in the doc to haproxy not supporting keep-alive have
been fixed, and the doc for config options has been updated.
At the very beginning of haproxy, there was "option httpclose" to make
haproxy add a "Connection: close" header in both directions to invite
both sides to agree on closing the connection. It did not work with some
rare products, so "option forceclose" was added to do the same and actively
close the connection. Then client-side keep-alive was supported, so option
http-server-close was introduced. Now we have keep-alive with a fourth
option, not to mention the implicit tunnel mode.
The connection configuration has become a total mess because all the
options above may be combined together, despite almost everyone thinking
they cancel each other, as judging from the common problem reports on the
mailing list. Unfortunately, re-reading the doc shows that it's not clear
at all that options may be combined, and the opposite seems more obvious
since they're compared. The most common issue is options being set in the
defaults section that are not negated in other sections, but are just
combined when the user expects them to be overloaded. The migration to
keep-alive by default will only make things worse.
So let's start to address the first problem. A transaction can only work in
5 modes today :
- tunnel : haproxy doesn't bother with what follows the first req/resp
- passive close : option http-close
- forced close : option forceclose
- server close : option http-server-close with keep-alive on the client side
- keep-alive : option http-keep-alive, end to end
All 16 combination for each section fall into one of these cases. Same for
the 256 combinations resulting from frontend+backend different modes.
With this patch, we're doing something slightly different, which will not
change anything for users with valid configs, and will only change the
behaviour for users with unsafe configs. The principle is that these options
may not combined anymore, and that the latest one always overrides all the
other ones, including those inherited from the defaults section. The "no
option xxx" statement is still supported to cancel one option and fall back
to the default one. It is mainly needed to ignore defaults sections (eg:
force the tunnel mode). The frontend+backend combinations have not changed.
So for examplen the following configuration used to put the connection
into forceclose :
defaults http
mode http
option httpclose
frontend foo.
option http-server-close
=> http-server-close+httpclose = forceclose before this patch! Now
the frontend's config replaces the defaults config and results in
the more expected http-server-close.
All 25 combinations of the 5 modes in (frontend,backend) have been
successfully tested.
In order to prepare for upcoming changes, a new "option http-tunnel" was
added. It currently only voids all other options, and has the lowest
precedence when mixed with another option in another frontend/backend.
