This is in order to add new types. This patch does not change anything
else. Two remaining (harmless) occurrences of a count of 8 instead of 7
were fixed by this patch : empty_arg_list[] and the for() loop counting
args.
It applies to the channel and it doesn't erase outgoing data, only
pending unread data, which is strictly equivalent to what recv()
does with MSG_TRUNC, so that new name is more accurate and intuitive.
This name more accurately reminds that it applies to a channel and not
to a buffer, and that what is returned may be used as a max number of
bytes to pass to recv().
This applies to the channel, not the buffer, so let's fix this name.
Warning, the function's name happens to be the same as the old one
which was mistakenly used during 1.5.
This function's name was poorly chosen and is confusing to the point of
being suspiciously used at some places. The operations it does always
consider the ability to forward pending input data before receiving new
data. This is not obvious at all, especially at some places where it was
used when consuming outgoing data to know if the buffer has any chance
to ever get the missing data. The code needs to be re-audited with that
in mind. Care must be taken with existing code since the polarity of the
function was switched with the renaming.
channel_reserved is confusingly named. It is used to know whether or
not the rewrite area is left intact for situations where we want to
ensure we can use it before proceeding. Let's rename it to fix this
confusion.
Option http-send-name-header is still hurting. If a POST request has to be
redispatched when this option is used, and the next server's name is larger
than the initial one, and the POST body fills the buffer, it becomes
impossible to rewrite the server's name in the buffer when redispatching.
In 1.4, this is worse, the process may crash because of a negative size
computation for the memmove().
The only solution to fix this is to refrain from eating the reserve before
we're certain that we won't modify the buffer anymore. And the condition for
that is that the connection is established.
This patch introduces "channel_may_send()" which helps to detect whether it's
safe to eat the reserve or not. This condition is used by channel_in_transit()
introduced by recent patches.
This patch series must be backported into 1.5, and a simpler version must be
backported into 1.4 where fixing the bug is much easier since there were no
channels by then. Note that in 1.4 the severity is major.
This function returns the amount of bytes in transit in a channel's buffer,
which is the amount of outgoing data plus the amount of incoming data bound
to the forward limit.
We know that all incoming data are going to be purged if to_forward
is greater than them, not only if greater than the buffer size. This
buf has no direct impact on this version, but it participates to some
bugs affecting http-send-name-header since 1.4. This fix will have to
be backported down to 1.4 albeit in a different form.
The buffer_max_len() function is subject to an integer overflow in this
calculus :
int ret = global.tune.maxrewrite - chn->to_forward - chn->buf->o;
- chn->to_forward may be up to 2^31 - 1
- chn->buf->o may be up to chn->buf->size
- global.tune.maxrewrite is by definition smaller than chn->buf->size
Thus here we can subtract (2^31 + buf->o) (highly negative) from something
slightly positive, and result in ret being larger than expected.
Fortunately in 1.5 and 1.6, this is only used by bi_avail() which itself
is used by applets which do not set high values for to_forward so this
problem does not happen there. However in 1.4 the equivalent computation
was used to limit the size of a read and can result in a read overflow
when combined with the nasty http-send-name-header feature.
This fix must be backported to 1.5 and 1.4.
Since commit 3dd6a25 ("MINOR: stream-int: retrieve session pointer from
stream-int"), we can get the session from the task, so let's get rid of
this less obvious function.
bi_swpbuf() swaps the buffer passed in argument with the one attached to
the channel, but only if this last one is empty. The idea is to avoid a
copy when buffers can simply be swapped.
We've already experimented with three wake up algorithms when releasing
buffers : the first naive one used to wake up far too many sessions,
causing many of them not to get any buffer. The second approach which
was still in use prior to this patch consisted in waking up either 1
or 2 sessions depending on the number of FDs we had released. And this
was still inaccurate. The third one tried to cover the accuracy issues
of the second and took into consideration the number of FDs the sessions
would be willing to use, but most of the time we ended up waking up too
many of them for nothing, or deadlocking by lack of buffers.
This patch completely removes the need to allocate two buffers at once.
Instead it splits allocations into critical and non-critical ones and
implements a reserve in the pool for this. The deadlock situation happens
when all buffers are be allocated for requests pending in a maxconn-limited
server queue, because then there's no more way to allocate buffers for
responses, and these responses are critical to release the servers's
connection in order to release the pending requests. In fact maxconn on
a server creates a dependence between sessions and particularly between
oldest session's responses and latest session's requests. Thus, it is
mandatory to get a free buffer for a response in order to release a
server connection which will permit to release a request buffer.
Since we definitely have non-symmetrical buffers, we need to implement
this logic in the buffer allocation mechanism. What this commit does is
implement a reserve of buffers which can only be allocated for responses
and that will never be allocated for requests. This is made possible by
the requester indicating how much margin it wants to leave after the
allocation succeeds. Thus it is a cooperative allocation mechanism : the
requester (process_session() in general) prefers not to get a buffer in
order to respect other's need for response buffers. The session management
code always knows if a buffer will be used for requests or responses, so
that is not difficult :
- either there's an applet on the initiator side and we really need
the request buffer (since currently the applet is called in the
context of the session)
- or we have a connection and we really need the response buffer (in
order to support building and sending an error message back)
This reserve ensures that we don't take all allocatable buffers for
requests waiting in a queue. The downside is that all the extra buffers
are really allocated to ensure they can be allocated. But with small
values it is not an issue.
With this change, we don't observe any more deadlocks even when running
with maxconn 1 on a server under severely constrained memory conditions.
The code becomes a bit tricky, it relies on the scheduler's run queue to
estimate how many sessions are already expected to run so that it doesn't
wake up everyone with too few resources. A better solution would probably
consist in having two queues, one for urgent requests and one for normal
requests. A failed allocation for a session dealing with an error, a
connection event, or the need for a response (or request when there's an
applet on the left) would go to the urgent request queue, while other
requests would go to the other queue. Urgent requests would be served
from 1 entry in the pool, while the regular ones would be served only
according to the reserve. Despite not yet having this, it works
remarkably well.
This mechanism is quite efficient, we don't perform too many wake up calls
anymore. For 1 million sessions elapsed during massive memory contention,
we observe about 4.5M calls to process_session() compared to 4.0M without
memory constraints. Previously we used to observe up to 16M calls, which
rougly means 12M failures.
During a test run under high memory constraints (limit enforced to 27 MB
instead of the 58 MB normally needed), performance used to drop by 53% prior
to this patch. Now with this patch instead it *increases* by about 1.5%.
The best effect of this change is that by limiting the memory usage to about
2/3 to 3/4 of what is needed by default, it's possible to increase performance
by up to about 18% mainly due to the fact that pools are reused more often
and remain hot in the CPU cache (observed on regular HTTP traffic with 20k
objects, buffers.limit = maxconn/10, buffers.reserve = limit/2).
Below is an example of scenario which used to cause a deadlock previously :
- connection is received
- two buffers are allocated in process_session() then released
- one is allocated when receiving an HTTP request
- the second buffer is allocated then released in process_session()
for request parsing then connection establishment.
- poll() says we can send, so the request buffer is sent and released
- process session gets notified that the connection is now established
and allocates two buffers then releases them
- all other sessions do the same till one cannot get the request buffer
without hitting the margin
- and now the server responds. stream_interface allocates the response
buffer and manages to get it since it's higher priority being for a
response.
- but process_session() cannot allocate the request buffer anymore
=> We could end up with all buffers used by responses so that none may
be allocated for a request in process_session().
When the applet processing leaves the session context, the test will have
to be changed so that we always allocate a response buffer regardless of
the left side (eg: H2->H1 gateway). A final improvement would consists in
being able to only retry the failed I/O operation without waking up a
task, but to date all experiments to achieve this have proven not to be
reliable enough.
When a session_alloc_buffers() fails to allocate one or two buffers,
it subscribes the session to buffer_wq, and waits for another session
to release buffers. It's then removed from the queue and woken up with
TASK_WAKE_RES, and can attempt its allocation again.
We decide to try to wake as many waiters as we release buffers so
that if we release 2 and two waiters need only once, they both have
their chance. We must never come to the situation where we don't wake
enough tasks up.
It's common to release buffers after the completion of an I/O callback,
which can happen even if the I/O could not be performed due to half a
failure on memory allocation. In this situation, we don't want to move
out of the wait queue the session that was just added, otherwise it
will never get any buffer. Thus, we only force ourselves out of the
queue when freeing the session.
Note: at the moment, since session_alloc_buffers() is not used, no task
is subscribed to the wait queue.
This patch introduces session_alloc_recv_buffer(), session_alloc_buffers()
and session_release_buffers() whose purpose will be to allocate missing
buffers and release unneeded ones around the process_session() and during
I/O operations.
I/O callbacks only need a single buffer for recv operations and none
for send. However we still want to ensure that we don't pick the last
buffer. That's what session_alloc_recv_buffer() is for.
This allocator is atomic in that it always ensures we can get 2 buffers
or fails. Here, if any of the buffers is not ready and cannot be
allocated, the operation is cancelled. The purpose is to guarantee that
we don't enter into the deadlock where all buffers are allocated by the
same size of all sessions.
A queue will have to be implemented for failed allocations. For now
they're just reported as failures.
Till now we'd consider a buffer full even if it had size==0 due to pointing
to buf.size. Now we change this : if buf_wanted is present, it means that we
have already tried to allocate a buffer but failed. Thus the buffer must be
considered full so that we stop trying to poll for reads on it. Otherwise if
it's empty, it's buf_empty and we report !full since we may allocate it on
the fly.
Channels are now created with a valid pointer to a buffer before the
buffer is allocated. This buffer is a global one called "buf_empty" and
of size zero. Thus it prevents any activity from being performed on
the buffer and still ensures that chn->buf may always be dereferenced.
b_free() also resets the buffer to &buf_empty, and was split into
b_drop() which does not reset the buffer.
We'll soon need to be able to switch buffers without touching the
channel, so let's move buffer initialization out of channel_init().
We had the same in compressoin.c.
Since commit 656c5fa7e8 ("BUILD: ssl: disable OCSP when using
boringssl) the OCSP code is bypassed when OPENSSL_IS_BORINGSSL
is defined. The correct thing to do here is to use OPENSSL_NO_OCSP
instead, which is defined for this exact purpose in
openssl/opensslfeatures.h.
This makes haproxy forward compatible if boringssl ever introduces
full OCSP support with the additional benefit that it links fine
against a OCSP-disabled openssl.
Signed-off-by: Lukas Tribus <luky-37@hotmail.com>
A memory optimization can use the same pattern expression for many
equal pattern list (same parse method, index method and index_smp
method).
The pattern expression is returned by "pattern_new_expr", but this
function dont indicate if the returned pattern is already in use.
So, the caller function reload the list of patterns in addition with
the existing patterns. This behavior is not a problem with tree indexed
pattern, but it grows the lists indexed patterns.
This fix add a "reuse" flag in return of the function "pattern_new_expr".
If the flag is set, I suppose that the patterns are already loaded.
This fix must be backported into 1.5.
In order for HTTP/2 not to eat too much memory, we'll have to support
on-the-fly buffer allocation, since most streams will have an empty
request buffer at some point. Supporting allocation on the fly means
being able to sleep inside I/O callbacks if a buffer is not available.
Till now, the I/O callbacks were called from two locations :
- when processing the cached events
- when processing the polled events from the poller
This change cleans up the design a bit further than what was started in
1.5. It now ensures that we never call any iocb from the poller itself
and that instead, events learned by the poller are put into the cache.
The benefit is important in terms of stability : we don't have to care
anymore about the risk that new events are added into the poller while
processing its events, and we're certain that updates are processed at
a single location.
To achieve this, we now modify all the fd_* functions so that instead of
creating updates, they add/remove the fd to/from the cache depending on
its state, and only create an update when the polling status reaches a
state where it will have to change. Since the pollers make use of these
functions to notify readiness (using fd_may_recv/fd_may_send), the cache
is always up to date with the poller.
Creating updates only when the polling status needs to change saves a
significant amount of work for the pollers : a benchmark showed that on
a typical TCP proxy test, the amount of updates per connection dropped
from 11 to 1 on average. This also means that the update list is smaller
and has more chances of not thrashing too many CPU cache lines. The first
observed benefit is a net 2% performance gain on the connection rate.
A second benefit is that when a connection is accepted, it's only when
we're processing the cache, and the recv event is automatically added
into the cache *after* the current one, resulting in this event to be
processed immediately during the same loop. Previously we used to have
a second run over the updates to detect if new events were added to
catch them before waking up tasks.
The next gain will be offered by the next steps on this subject consisting
in implementing an I/O queue containing all cached events ordered by priority
just like the run queue, and to be able to leave some events pending there
as long as needed. That will allow us *not* to perform some FD processing
if it's not the proper time for this (typically keep waiting for a buffer
to be allocated if none is available for an recv()). And by only processing
a small bunch of them, we'll allow priorities to take place even at the I/O
level.
As a result of this change, functions fd_alloc_or_release_cache_entry()
and fd_process_polled_events() have disappeared, and the code dedicated
to checking for new fd events after the callback during the poll() loop
was removed as well. Despite the patch looking large, it's mostly a
change of what function is falled upon fd_*() and almost nothing was
added.
This patch makes it possible to create binds and servers in separate
namespaces. This can be used to proxy between multiple completely independent
virtual networks (with possibly overlapping IP addresses) and a
non-namespace-aware proxy implementation that supports the proxy protocol (v2).
The setup is something like this:
net1 on VLAN 1 (namespace 1) -\
net2 on VLAN 2 (namespace 2) -- haproxy ==== proxy (namespace 0)
net3 on VLAN 3 (namespace 3) -/
The proxy is configured to make server connections through haproxy and sending
the expected source/target addresses to haproxy using the proxy protocol.
The network namespace setup on the haproxy node is something like this:
= 8< =
$ cat setup.sh
ip netns add 1
ip link add link eth1 type vlan id 1
ip link set eth1.1 netns 1
ip netns exec 1 ip addr add 192.168.91.2/24 dev eth1.1
ip netns exec 1 ip link set eth1.$id up
...
= 8< =
= 8< =
$ cat haproxy.cfg
frontend clients
bind 127.0.0.1:50022 namespace 1 transparent
default_backend scb
backend server
mode tcp
server server1 192.168.122.4:2222 namespace 2 send-proxy-v2
= 8< =
A bind line creates the listener in the specified namespace, and connections
originating from that listener also have their network namespace set to
that of the listener.
A server line either forces the connection to be made in a specified
namespace or may use the namespace from the client-side connection if that
was set.
For more documentation please read the documentation included in the patch
itself.
Signed-off-by: KOVACS Tamas <ktamas@balabit.com>
Signed-off-by: Sarkozi Laszlo <laszlo.sarkozi@balabit.com>
Signed-off-by: KOVACS Krisztian <hidden@balabit.com>
When we're stopping, we're not going to create new tasks anymore, so
let's release the task pool upon each task_free() in order to reduce
memory fragmentation.
Commit 179085c ("MEDIUM: http: move Connection header processing earlier")
introduced a regression : the backend's HTTP mode is not considered anymore
when setting the session's HTTP mode, because wait_for_request() is only
called once, when the frontend receives the request (or when the frontend
is in TCP mode, when the backend receives the request).
The net effect is that in some situations when the frontend and the backend
do not work in the same mode (eg: keep-alive vs close), the backend's mode
is ignored.
This patch moves all that processing to a dedicated function, which is
called from the original place, as well as from session_set_backend()
when switching from an HTTP frontend to an HTTP backend in different
modes.
This fix must be backported to 1.5.
There are two sample commands to get information about the presence of a
client certificate.
ssl_fc_has_crt is true if there is a certificate present in the current
connection
ssl_c_used is true if there is a certificate present in the session.
If a session has stopped and resumed, then ssl_c_used could be true, while
ssl_fc_has_crt is false.
In the client byte of the TLS TLV of Proxy Protocol V2, there is only one
bit to indicate whether a certificate is present on the connection. The
attached patch adds a second bit to indicate the presence for the session.
This maintains backward compatibility.
[wt: this should be backported to 1.5 to help maintain compatibility
between versions]
Google's boringssl doesn't currently support OCSP, so
disable it if detected.
OCSP support may be reintroduced as per:
https://code.google.com/p/chromium/issues/detail?id=398677
In that case we can simply revert this commit.
Signed-off-by: Lukas Tribus <luky-37@hotmail.com>
If a source file includes proto/server.h twice or more, redefinition errors will
be triggered for such inline functions as server_throttle_rate(),
server_is_draining(), srv_adm_set_maint() and so on. Just move #endif directive
to the end of file to solve this issue.
Signed-off-by: Godbach <nylzhaowei@gmail.com>
Add support for http-request track-sc, similar to what is done in
tcp-request for backends. A new act_prm field was added to HTTP
request rules to store the track params (table, counter). Just
like for TCP rules, the table is resolved while checking for
config validity. The code was mostly copied from the TCP code
with the exception that here we also count the HTTP request count
and rate by hand. Probably that something could be factored out in
the future.
It seems like tracking flags should be improved to mark each hook
which tracks a key so that we can have some check points where to
increase counters of the past if not done yet, a bit like is done
for TRACK_BACKEND.
Some users want to add their own data types to stick tables. We don't
want to use a linked list here for performance reasons, so we need to
continue to use an indexed array. This patch allows one to reserve a
compile-time-defined number of extra data types by setting the new
macro STKTABLE_EXTRA_DATA_TYPES to anything greater than zero, keeping
in mind that anything larger will slightly inflate the memory consumed
by stick tables (not per entry though).
Then calling stktable_register_data_store() with the new keyword will
either register a new keyword or fail if the desired entry was already
taken or the keyword already registered.
Note that this patch does not dictate how the data will be used, it only
offers the possibility to create new keywords and have an index to
reference them in the config and in the tables. The caller will not be
able to use stktable_data_cast() and will have to explicitly cast the
stable pointers to the expected types. It can be used for experimentation
as well.
Currently we have stktable_fetch_key() which fetches a sample according
to an expression and returns a stick table key, but we also need a function
which does only the second half of it from a known sample. So let's cut the
function in two and introduce smp_to_stkey() to perform this lookup. The
first function was adapted to make use of it in order to avoid code
duplication.
Abstract namespace sockets ignore the shutdown() call and do not make
it possible to temporarily stop listening. The issue it causes is that
during a soft reload, the new process cannot bind, complaining that the
address is already in use.
This change registers a new pause() function for unix sockets and
completely unbinds the abstract ones since it's possible to rebind
them later. It requires the two previous patches as well as preceeding
fixes.
This fix should be backported into 1.5 since the issue apperas there.
In order to fix the abstact socket pause mechanism during soft restarts,
we'll need to proceed differently depending on the socket protocol. The
pause_listener() function already supports some protocol-specific handling
for the TCP case.
This commit makes this cleaner by adding a new ->pause() function to the
protocol struct, which, if defined, may be used to pause a listener of a
given protocol.
For now, only TCP has been adapted, with the specific code moved from
pause_listener() to tcp_pause_listener().
With all the goodies supported by logformat, people find that the limit
of 1024 chars for log lines is too short. Some servers do not support
larger lines and can simply drop them, so changing the default value is
not always the best choice.
This patch takes a different approach. Log line length is specified per
log server on the "log" line, with a value between 80 and 65535. That
way it's possibly to satisfy all needs, even with some fat local servers
and small remote ones.
stktable_fetch_key() does not indicate whether it returns NULL because
the input sample was not found or because it's unstable. It causes trouble
with track-sc* rules. Just like with sample_fetch_string(), we want it to
be able to give more information to the caller about what it found. Thus,
now we use the pointer to a sample passed by the caller, and fill it with
the information we have about the sample. That way, even if we return NULL,
the caller has the ability to check whether a sample was found and if it is
still changing or not.
'ssl_sock_get_common_name' applied to a connection was also renamed
'ssl_sock_get_remote_common_name'. Currently, this function is only used
with protocol PROXYv2 to retrieve the client certificate's common name.
A further usage could be to retrieve the server certificate's common name
on an outgoing connection.
The support is all based on static responses. This doesn't add any
request / response logic to HAProxy, but allows a way to update
information through the socket interface.
Currently certificates specified using "crt" or "crt-list" on "bind" lines
are loaded as PEM files.
For each PEM file, haproxy checks for the presence of file at the same path
suffixed by ".ocsp". If such file is found, support for the TLS Certificate
Status Request extension (also known as "OCSP stapling") is automatically
enabled. The content of this file is optional. If not empty, it must contain
a valid OCSP Response in DER format. In order to be valid an OCSP Response
must comply with the following rules: it has to indicate a good status,
it has to be a single response for the certificate of the PEM file, and it
has to be valid at the moment of addition. If these rules are not respected
the OCSP Response is ignored and a warning is emitted. In order to identify
which certificate an OCSP Response applies to, the issuer's certificate is
necessary. If the issuer's certificate is not found in the PEM file, it will
be loaded from a file at the same path as the PEM file suffixed by ".issuer"
if it exists otherwise it will fail with an error.
It is possible to update an OCSP Response from the unix socket using:
set ssl ocsp-response <response>
This command is used to update an OCSP Response for a certificate (see "crt"
on "bind" lines). Same controls are performed as during the initial loading of
the response. The <response> must be passed as a base64 encoded string of the
DER encoded response from the OCSP server.
Example:
openssl ocsp -issuer issuer.pem -cert server.pem \
-host ocsp.issuer.com:80 -respout resp.der
echo "set ssl ocsp-response $(base64 -w 10000 resp.der)" | \
socat stdio /var/run/haproxy.stat
This feature is automatically enabled on openssl 0.9.8h and above.
This work was performed jointly by Dirkjan Bussink of GitHub and
Emeric Brun of HAProxy Technologies.
This patch adds two new actions to http-request and http-response rulesets :
- replace-header : replace a whole header line, suited for headers
which might contain commas
- replace-value : replace a single header value, suited for headers
defined as lists.
The match consists in a regex, and the replacement string takes a log-format
and supports back-references.
Using the last rate counters, we now compute the queue, connect, response
and total times per server and per backend with a 95% accuracy over the last
1024 samples. The operation is cheap so we don't need to condition it.
While the current functions report average event counts per period, we are
also interested in average values per event. For this we use a different
method. The principle is to rely on a long tail which sums the new value
with a fraction of the previous value, resulting in a sliding window of
infinite length depending on the precision we're interested in.
The idea is that we always keep (N-1)/N of the sum and add the new sampled
value. The sum over N values can be computed with a simple program for a
constant value 1 at each iteration :
N
,---
\ N - 1 e - 1
> ( --------- )^x ~= N * -----
/ N e
'---
x = 1
Note: I'm not sure how to demonstrate this but at least this is easily
verified with a simple program, the sum equals N * 0.632120 for any N
moderately large (tens to hundreds).
Inserting a constant sample value V here simply results in :
sum = V * N * (e - 1) / e
But we don't want to integrate over a small period, but infinitely. Let's
cut the infinity in P periods of N values. Each period M is exactly the same
as period M-1 with a factor of ((N-1)/N)^N applied. A test shows that given a
large N :
N - 1 1
( ------- )^N ~= ---
N e
Our sum is now a sum of each factor times :
N*P P
,--- ,---
\ N - 1 e - 1 \ 1
> v ( --------- )^x ~= VN * ----- * > ---
/ N e / e^x
'--- '---
x = 1 x = 0
For P "large enough", in tests we get this :
P
,---
\ 1 e
> --- ~= -----
/ e^x e - 1
'---
x = 0
This simplifies the sum above :
N*P
,---
\ N - 1
> v ( --------- )^x = VN
/ N
'---
x = 1
So basically by summing values and applying the last result an (N-1)/N factor
we just get N times the values over the long term, so we can recover the
constant value V by dividing by N.
A value added at the entry of the sliding window of N values will thus be
reduced to 1/e or 36.7% after N terms have been added. After a second batch,
it will only be 1/e^2, or 13.5%, and so on. So practically speaking, each
old period of N values represents only a quickly fading ratio of the global
sum :
period ratio
1 36.7%
2 13.5%
3 4.98%
4 1.83%
5 0.67%
6 0.25%
7 0.09%
8 0.033%
9 0.012%
10 0.0045%
So after 10N samples, the initial value has already faded out by a factor of
22026, which is quite fast. If the sliding window is 1024 samples wide, it
means that a sample will only count for 1/22k of its initial value after 10k
samples went after it, which results in half of the value it would represent
using an arithmetic mean. The benefit of this method is that it's very cheap
in terms of computations when N is a power of two. This is very well suited
to record response times as large values will fade out faster than with an
arithmetic mean and will depend on sample count and not time.
Demonstrating all the above assumptions with maths instead of a program is
left as an exercise for the reader.
This patch adds support for a new "drain" mode. So now we have 3 admin
modes for a server :
- READY
- DRAIN
- MAINT
The drain mode disables load balancing but leaves the server up. It can
coexist with maint, except that maint has precedence. It is also inherited
from tracked servers, so just like maint, it's represented with 2 bits.
New functions were designed to set/clear each flag and to propagate the
changes to tracking servers when relevant, and to log the changes. Existing
functions srv_set_adm_maint() and srv_set_adm_ready() were replaced to make
use of the new functions.
Currently the drain mode is not yet used, however the whole logic was tested
with all combinations of set/clear of both flags in various orders to catch
all corner cases.
This function was taken from check_set_server_drain(). It does not
consider health checks at all and only sets a server to stopping
provided it's not in maintenance and is not currently stopped. The
resulting state will be STOPPING. The state change is propagated
to tracked servers.
For now the function is not used, but the goal is to split health
checks status from server status and to be able to change a server's
state regardless of health checks statuses.
This function was taken from check_set_server_up(). It does not consider
health checks at all and only sets a server up provided it's not in
maintenance. The resulting state may be either RUNNING or STARTING
depending on the presence of a slowstart or not. The state change is
propagated to tracked servers.
For now the function is not used, but the goal is to split health
checks status from server status and to be able to change a server's
state regardless of health checks statuses.
This function was extracted from check_set_server_down(). In only
manipulates the server state and does not consider the health checks
at all, nor does it modify their status. It takes a reason message to
report in logs, however it passes NULL when recursing through the
trackers chain.
For now the function is not used, but the goal is to split health
checks status from server status and to be able to change a server's
state regardless of health checks statuses.
srv_adm_append_status() was renamed srv_append_status() since it's no
more dedicated to maintenance mode. It now supports a reason which if
not null is appended to the output string.
