SPOE makes possible the communication with external components to retrieve some
info using an in-house binary protocol, the Stream Processing Offload Protocol
(SPOP). In the long term, its aim is to allow any kind of offloading on the
streams. This first version, besides being experimental, won't do lot of
things. The most important today is to validate the protocol design and lay the
foundations of what will, one day, be a full offload engine for the stream
processing.
So, for now, the SPOE can offload the stream processing before "tcp-request
content", "tcp-response content", "http-request" and "http-response" rules. And
it only supports variables creation/suppression. But, in spite of these limited
features, we can easily imagine to implement a SSO solution, an ip reputation
service or an ip geolocation service.
Internally, the SPOE is implemented as a filter. So, to use it, you must use
following line in a proxy proxy section:
frontend my-front
...
filter spoe [engine <name>] config <file>
...
It uses its own configuration file to keep the HAProxy configuration clean. It
is also a easy way to disable it by commenting out the filter line.
See "doc/SPOE.txt" for all details about the SPOE configuration.
It does the opposite of 'set-var' action/converter. It is really useful for
per-process variables. But, it can be used for any scope.
The lua function 'unset_var' has also been added.
Now it is possible to use variables attached to a process. The scope name is
'proc'. These variables are released only when HAProxy is stopped.
'tune.vars.proc-max-size' directive has been added to confiure the maximum
amount of memory used by "proc" variables. And because memory accounting is
hierachical for variables, memory for "proc" vars includes memory for "sess"
vars.
This function, unsurprisingly, sets a variable value only if it already
exists. In other words, this function will succeed only if the variable was
found somewhere in the configuration during HAProxy startup.
It will be used by SPOE filter. So an agent will be able to set a value only for
existing variables. This prevents an agent to create a very large number of
unused variables to flood HAProxy and exhaust the memory reserved to variables..
This code has been moved from haproxy.c to sample.c and the function
release_sample_expr can now be called from anywhere to release a sample
expression. This function will be used by the stream processing offload engine
(SPOE).
A scope is a section name between square bracket, alone on its line, ie:
[scope-name]
...
The spaces at the beginning and at the end of the line are skipped. Comments at
the end of the line are also skipped.
When a scope is parsed, its name is saved in the global variable
cfg_scope. Initially, cfg_scope is NULL and it remains NULL until a valid scope
line is parsed.
This feature remains unused in the HAProxy configuration file and
undocumented. However, it will be used during SPOE configuration parsing.
This feature will be used by the stream processing offload engine (SPOE) to
parse dedicated configuration files without mixing HAProxy sections with SPOE
sections.
So, here we can back up all sections known by HAProxy, unregister all of them
and add new ones, dedicted to the SPOE. Once the SPOE configuration file parsed,
we can roll back all changes by restoring HAProxy sections.
Now, for TCP streams, backend filters are released when the stream is
destroyed. But, for HTTP streams, these filters are released when the
transaction analyze ends, in flt_end_analyze callback.
New callbacks have been added to handle creation and destruction of filter
instances:
* 'attach' callback is called after a filter instance creation, when it is
attached to a stream. This happens when the stream is started for filters
defined on the stream's frontend and when the backend is set for filters
declared on the stream's backend. It is possible to ignore the filter, if
needed, by returning 0. This could be useful to have conditional filtering.
* 'detach' callback is called when a filter instance is detached from a stream,
before its destruction. This happens when the stream is stopped for filters
defined on the stream's frontend and when the analyze ends for filters defined
on the stream's backend.
In addition, the callback 'stream_set_backend' has been added to know when a
backend is set for a stream. It is only called when the frontend and the backend
are not the same. And it is called for all filters attached to a stream
(frontend and backend).
Finally, the TRACE filter has been updated.
The 'set-var' converter uses function smp_conv_store (vars.c). In this function,
we should use the first argument (index 0) to retrieve the variable name and its
scope. But because of a typo, we get the scope of the second argument (index
1). In this case, there is no second argument. So the scope used was always 0
(SCOPE_SESS), always setting the variable in the session scope.
So, due to this bug, this rules
tcp-request content accept if { src,set-var(txn.foo) -m found }
always set the variable 'sess.foo' instead of 'txn.foo'.
Now that it is possible to decide whether we prefer to use libc or the
state file to resolve the server's IP address and it is possible to change
a server's IP address at run time on the CLI, let's not restrict the reuse
of the address from the state file anymore to the DNS only.
The impact is that by default the state file will be considered first
(which matches its purpose) and only then the libc. This way any address
change performed at run time over the CLI will be preserved regardless
of DNS usage or not.
It is very common when validating a configuration out of production not to
have access to the same resolvers and to fail on server address resolution,
making it difficult to test a configuration. This option simply appends the
"none" method to the list of address resolution methods for all servers,
ensuring that even if the libc fails to resolve an address, the startup
sequence is not interrupted.
This will allow a server to automatically fall back to an explicit numeric
IP address when all other methods fail. The address is simply specified in
the address list.
Now that we have "init-addr none", it becomes possible to recover on
libc resolver's failures. Thus it's preferable not to alert nor fail
at the moment the libc is called, and instead process the failure at
the end of the list. This allows "none" to be set after libc to
provide a smooth fallback in case of resolver issues.
This new setting supports a comma-delimited list of methods used to
resolve the server's FQDN to an IP address. Currently supported methods
are "libc" (use the regular libc's resolver) and "last" (use the last
known valid address found in the state file).
The list is implemented in a 32-bit integer, because each init-addr
method only requires 3 bits. The last one must always be SRV_IADDR_END
(0), allowing to store up to 10 methods in a single 32 bit integer.
Note: the doc is provided at the end of this series.
The RMAINT state happens when a server doesn't get a valid DNS response
past the hold time. If the address is forced on the CLI, we must use it
and leave the RMAINT state.
WARNING: this is a MAJOR (and disruptive) change with previous HAProxy's
behavior: before, HAProxy never ever used to change a server administrative
status when the DNS resolution failed at run time.
This patch gives HAProxy the ability to change the administrative status
of a server to MAINT (RMAINT actually) when an error is encountered for
a period longer than its own allowed by the corresponding 'hold'
parameter.
IE if the configuration sets "hold nx 10s" and a server's hostname
points to a NX for more than 10s, then the server will be set to RMAINT,
hence in MAINTENANCE mode.
This adds new "hold" timers : nx, refused, timeout, other. This timers
will be used to tell HAProxy to keep an erroneous response as valid for
the corresponding period. For now they're only configured, not enforced.
It will be important to help debugging some DNS resolution issues to
know why a server was marked down, so let's make the function support
a 3rd argument with an indication of the reason. Passing NULL will keep
the message as-is.
The server's state is now "MAINT (resolution)" just like we also have
"MAINT (via x/y)" when servers are tracked. The HTML stats page reports
"resolution" in the checks field similarly to what is done for the "via"
entry.
It's important to report in the server state change logs that RMAINT was
cleared, as it's not the regular maintenance mode, it's specific to name
resolution, and it's important to report the new state (which can be DRAIN
or READY).
This flag has to be set when an IP address resolution fails (either
using libc at start up or using HAProxy's runtime resolver). This will
automatically trigger the administrative status "MAINT", through the
global mask SRV_ADMF_MAINT.
Server addresses are not resolved anymore upon the first pass so that we
don't fail if an address cannot be resolved by the libc. Instead they are
processed all at once after the configuration is fully loaded, by the new
function srv_init_addr(). This function only acts on the server's address
if this address uses an FQDN, which appears in server->hostname.
For now the function does two things, to followup with HAProxy's historical
default behavior:
1. apply server IP address found in server-state file if runtime DNS
resolution is enabled for this server
2. use the DNS resolver provided by the libc
If none of the 2 options above can find an IP address, then an error is
returned.
All of this will be needed to support the new server parameter "init-addr".
For now, the biggest user-visible change is that all server resolution errors
are dumped at once instead of causing a startup failure one by one.
Currently, the function which applies server states provided by the
"old" process is applied after configuration sanity check. This results
in the impossibility to check the validity of the state file during a
regular config check, implying a full start is required, which can be
a problem sometimes.
This patch moves the loading of server_state file before MODE_CHECK.
This will be needed to later postpone server address resolution. We need the
FQDN even when it doesn't resolve. The caller then needs to check if fqdn was
set when resolve is null to detect that the address couldn't be parsed and
needs later resolution.
Quite a lot of people have been complaining about option contstats not
working correctly anymore since about 1.4. The reason was that one reason
for the significant performance boost between 1.3 and 1.4 was the ability
to forward data between a server and a client without waking up the stream
manager. And we couldn't afford to force sessions to constantly wake it
up given that most of the people interested in contstats are also those
interested in high performance transmission.
An idea was experimented with in the past, consisting in limiting the
amount of transmissible data before waking it up, but it was not usable
on slow connections (eg: FTP over modem lines, RDP, SSH) as stats would
be updated too rarely if at all, so that idea was dropped.
During a discussion today another idea came up : ensure that stats are
updated once in a while, since it's the only thing that matters. It
happens that we have the request channel's analyse_exp timeout that is
used to wake the stream up after a configured delay, and that by
definition this timeout is not used when there's no more analyser
(otherwise the stream would wake up and the stats would be updated).
Thus here the idea is to reuse this timeout when there's no analyser
and set it to now+5 seconds so that a stream wakes up at least once
every 5 seconds to update its stats. It should be short enough to
provide smooth traffic graphs and to allow to debug outputs of "show
sess" more easily without inflicting too much load even for very large
number of concurrent connections.
This patch is simple enough and safe enough to be backportable to 1.6
if there is some demand.
In the last release a lot of the structures have become opaque for an
end user. This means the code using these needs to be changed to use the
proper functions to interact with these structures instead of trying to
manipulate them directly.
This does not fix any deprecations yet that are part of 1.1.0, it only
ensures that it can be compiled against that version and is still
compatible with older ones.
[wt: openssl-0.9.8 doesn't build with it, there are conflicts on certain
function prototypes which we declare as inline here and which are
defined differently there. But openssl-0.9.8 is not supported anymore
so probably it's OK to go without it for now and we'll see later if
some users still need it. Emeric has reviewed this change and didn't
spot anything obvious which requires special care. Let's try it for
real now]
The only reason wurfl/wurfl.h was needed outside of wurfl.c was to expose
wurfl_handle which is a pointer to a structure, referenced by global.h.
By just storing a void* there instead, we can confine all wurfl code to
wurfl.c, which is really nice.
Both DeviceAtlas and 51Degrees used to put their building instructions
in the README, representing more than 1/3 of it. It's better to let the
README focus on generic stuff and building procedure and move the DD
docs to their own files.
WURFL is a high-performance and low-memory footprint mobile device
detection software component that can quickly and accurately detect
over 500 capabilities of visiting devices. It can differentiate between
portable mobile devices, desktop devices, SmartTVs and any other types
of devices on which a web browser can be installed.
In order to add WURFL device detection support, you would need to
download Scientiamobile InFuze C API and install it on your system.
Refer to www.scientiamobile.com to obtain a valid InFuze license.
Any useful information on how to configure HAProxy working with WURFL
may be found in:
doc/WURFL-device-detection.txt
doc/configuration.txt
examples/wurfl-example.cfg
Please find more information about WURFL device detection API detection
at https://docs.scientiamobile.com/documentation/infuze/infuze-c-api-user-guide
Right now there is an issue with the way the maintenance flags are
propagated upon startup. They are not propagate, just copied from the
tracked server. This implies that depending on the server's order, some
tracking servers may not be marked down. For example this configuration
does not work as expected :
server s1 1.1.1.1:8000 track s2
server s2 1.1.1.1:8000 track s3
server s3 1.1.1.1:8000 track s4
server s4 wtap:8000 check inter 1s disabled
It results in s1/s2 being up, and s3/s4 being down, while all of them
should be down.
The only clean way to process this is to run through all "root" servers
(those not tracking any other server), and to propagate their state down
to all their trackers. This is the same algorithm used to propagate the
state changes. It has to be done both to compute the IDRAIN flag and the
IMAINT flag. However, doing so requires that tracking servers are not
marked as inherited maintenance anymore while parsing the configuration
(and given that it is wrong, better drop it).
This fix also addresses another side effect of the bug above which is
that the IDRAIN/IMAINT flags are stored in the state files, and if
restored while the tracked server doesn't have the equivalent flag,
the servers may end up in a situation where it's impossible to remove
these flags. For example in the configuration above, after removing
"disabled" on server s4, the other servers would have remained down,
and not anymore with this fix. Similarly, the combination of IMAINT
or IDRAIN with their respective forced modes was not accepted on
reload, which is wrong as well.
This bug has been present at least since 1.5, maybe even 1.4 (it came
with tracking support). The fix needs to be backported there, though
the srv-state parts are irrelevant.
This commit relies on previous patch to silence warnings on startup.
We'll have to use srv_set_admin_flag() to propagate some server flags
during the startup, and we don't want the resulting actions to cause
warnings, logs nor e-mail alerts to be generated since we're just applying
the config or a state file. So let's condition these notifications to the
fact that we're starting.
CMAINT indicates that the server was *initially* disabled in the
configuration via the "disabled" keyword. FDRAIN indicates that the
server was switched to the DRAIN state from the CLI or the agent.
This it's perfectly valid to have both of them in the state file,
so the parser must not reject this combination.
This fix must be backported to 1.6.
There were seveal reports about the DRAIN state not being properly
restored upon reload.
It happens that the condition in the code does exactly the opposite
of what the comment says, and the comment is right so the code is
wrong.
It's worth noting that the conditions are complex here due to the 2
available methods to set the drain state (CLI/agent, and config's
weight). To paraphrase the updated comment in the code, there are
two possible reasons for FDRAIN to have been present :
- previous config weight was zero
- "set server b/s drain" was sent to the CLI
In the first case, we simply want to drop this drain state if the new
weight is not zero anymore, meaning the administrator has intentionally
turned the weight back to a positive value to enable the server again
after an operation. In the second case, the drain state was forced on
the CLI regardless of the config's weight so we don't want a change to
the config weight to lose this status. What this means is :
- if previous weight was 0 and new one is >0, drop the DRAIN state.
- if the previous weight was >0, keep it.
This fix must be backported to 1.6.
http_find_header2() relies on find_hdr_value_end() to find the comma
delimiting a header field value, which also properly handles double
quotes and backslashes within quotes. In fact double quotes are very
rare, and commas happen once every multiple characters, especially
with cookies where a full block can be found at once. So it makes
sense to optimize this function to speed up the lookup of the first
block before the quote.
This change increases the performance from 212k to 217k req/s when
requests contain a 1kB cookie (+2.5%). We don't care about going
back into the fast parser after the first quote, as it may
needlessly make the parser more complex for very marginal gains.
Searching the trailing space in long URIs takes some time. This can
happen especially on static files and some blogs. By skipping valid
character ranges by 32-bit blocks, it's possible to increase the
HTTP performance from 212k to 216k req/s on requests features a
100-character URI, which is an increase of 2%. This is done for
architectures supporting unaligned accesses (x86_64, x86, armv7a).
There's only a 32-bit version because URIs are rarely long and very
often short, so it's more efficient to limit the systematic overhead
than to try to optimize for the rarest requests.
A performance test with 1kB cookies was capping at 194k req/s. After
implementing multi-byte skipping, the performance increased to 212k req/s,
or 9.2% faster. This patch implements this for architectures supporting
unaligned accesses (x86_64, x86, armv7a). Maybe other architectures can
benefit from this but they were not tested yet.
We used to have 7 different character classes, each was 256 bytes long,
resulting in almost 2kB being used in the L1 cache. It's as cheap to
test a bit than to check the byte is not null, so let's store a 7-bit
composite value and check for the respective bits there instead.
The executable is now 4 kB smaller and the performance on small
objects increased by about 1% to 222k requests/second with a config
involving 4 http-request rules including 1 header lookup, one header
replacement, and 2 variable assignments.
ipcpy() is used to replace an IP address with another one, but it
doesn't preserve the original port so all callers have to do it
manually while it's trivial to do there. Better do it inside the
function.
Often we need to call str2ip2() on an address which already contains a
port without replacing it, so let's ensure we preserve it even if the
family changes.
Gabriele Cerami reported the the exit codes of the systemd-wrapper are
wrong. In short, it directly returns the output of the wait syscall's
status, which is a composite value made of error code an signal numbers.
In general it contains the signal number on the lower bits and the error
code on the higher bits, but exit() truncates it to the lowest 8 bits,
causing config validations to incorrectly report a success. Example :
$ ./haproxy-systemd-wrapper -c -f /dev/null
<7>haproxy-systemd-wrapper: executing /tmp/haproxy -c -f /dev/null -Ds
Configuration file has no error but will not start (no listener) => exit(2).
<5>haproxy-systemd-wrapper: exit, haproxy RC=512
$ echo $?
0
If the process is killed however, the signal number is directly reported
in the exit code.
Let's fix all this to ensure that the exit code matches what the shell does,
which means that codes 0..127 are for exit codes, codes 128..254 for signals,
and code 255 for unknown exit code. Now the return code is correct :
$ ./haproxy-systemd-wrapper -c -f /dev/null
<7>haproxy-systemd-wrapper: executing /tmp/haproxy -c -f /dev/null -Ds
Configuration file has no error but will not start (no listener) => exit(2).
<5>haproxy-systemd-wrapper: exit, haproxy RC=2
$ echo $?
2
$ ./haproxy-systemd-wrapper -f /tmp/cfg.conf
<7>haproxy-systemd-wrapper: executing /tmp/haproxy -f /dev/null -Ds
^C
<5>haproxy-systemd-wrapper: exit, haproxy RC=130
$ echo $?
130
This fix must be backported to 1.6 and 1.5.
