CONTRIB: opentracing: add the OpenTracing filter
This commit adds the OpenTracing filter (hereinafter we will use the
abbreviated name 'the OT filter') to the contrib tree.
The OT filter adds native support for using distributed tracing in HAProxy.
This is enabled by sending an OpenTracing compliant request to one of the
supported tracers; such as Datadog, Jaeger, Lightstep and Zipkin tracers.
Please note: tracers are not listed by any preference, but alphabetically.
The OT filter is a standard HAProxy filter, so what applies to others also
applies to this one (of course, by that I mean what is described in the
documentation, more precisely in the doc/internals/filters.txt file).
The OT filter activation is done explicitly by specifying it in the HAProxy
configuration. If this is not done, the OT filter in no way participates
in the work of HAProxy.
As for the impact on HAProxy speed, this is documented with several tests
located in the test directory, and the result is found in the README-speed-*
files. In short, the speed of operation depends on the way it is used and
the complexity of the configuration, from an almost immeasurable impact to
a significant deceleration (5x and more). I think that in some normal use
the speed of HAProxy with the filter on will be quite satisfactory with a
slowdown of less than 4%.
The OT filter allows intensive use of ACLs, which can be defined anywhere in
the configuration. Thus, it is possible to use the filter only for those
connections that are of interest to us.
More detailed documentation related to the operation, configuration and use
of the filter can be found in the contrib/opentracing directory.
To make the OpenTracing filter easier to configure and compile, several
entries have been added to the Makefile. When running the make utility,
it is possible to use several new arguments:
USE_OT=1 : enable the OpenTracing filter
OT_DEBUG=1 : compile the OpenTracing filter in debug mode
OT_INC=path : force the include path to libopentracing-c-wrapper
OT_LIB=path : force the lib path to libopentracing-c-wrapper
OT_RUNPATH=1 : add libopentracing-c-wrapper RUNPATH to haproxy executable
If USE_OT is set, then an additional Makefile from the contrib/opentracing
directory is included in the compilation process.
2020-12-09 15:54:31 +00:00
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/***
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* Copyright 2020 HAProxy Technologies
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*
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* This file is part of the HAProxy OpenTracing filter.
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*
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* This program is free software; you can redistribute it and/or
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* modify it under the terms of the GNU General Public License
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* as published by the Free Software Foundation; either version 2
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* of the License, or (at your option) any later version.
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*
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* This program is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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* GNU General Public License for more details.
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*
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* You should have received a copy of the GNU General Public License
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* along with this program; if not, write to the Free Software
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* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
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*/
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#ifndef _OPENTRACING_VARS_H_
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#define _OPENTRACING_VARS_H_
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#define FLT_OT_VARS_SCOPE "txn"
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MAJOR: opentracing: reenable usage of vars to transmit opentracing context
Since commit 3a4bedccc ("MEDIUM: vars: replace the global name index with
a hash") the names of HAProxy variables are no longer saved, ie their
64-bit hashes are saved instead.
This is very convenient for the HAProxy itself, but for the OpenTracing
module it is a problem because the names of the variables are important
when transferring the OpenTracing context. Namely, this context consists
of an unknown amount of data stored in a key-value format. The number
of these data (and the name of the variable used for this purpose) is
determined with the configuration of the OpenTracing filter, as well as
with the tracer used. The two previous sentences seem to be in conflict,
but that is only so at first glance. The function in the OpenTracing
filter used to read the context does not really know this, neither their
number nor its name. The only thing that function actually knows is the
prefix of the variable names used for context transfer, and by that it
could find all the necessary data. Of course, until the application of
the above-mentioned commit.
The problem is solved in a very simple way: in a common variable that
the filter always knows its name, the names of all variables that are the
product of the OpenTracing context are saved. The names of these context
variables can only be added to that common variable. When that variable
is no longer needed (when we no longer need context), it is deleted.
The format for saving data to this common variable is as follows:
+-----+---------------+-- .. --+-----+---------------+
| len | variable name | | len | variable name |
+-----+---------------+-- .. --+-----+---------------+
The amount of memory space used to store the length of the name is 1 byte,
with a sign (the minus sign is provided for inactive records, but this is
not currently used). This means that the maximum length of the variable
name to be saved is 127 characters, which is quite enough for use in the
filter. The buffer size for such data storage is global.tune.bufsize.
This patch must be backported in 2.5.
2022-03-09 23:03:24 +00:00
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#define FLT_OT_VAR_CTX_SIZE int8_t
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CONTRIB: opentracing: add the OpenTracing filter
This commit adds the OpenTracing filter (hereinafter we will use the
abbreviated name 'the OT filter') to the contrib tree.
The OT filter adds native support for using distributed tracing in HAProxy.
This is enabled by sending an OpenTracing compliant request to one of the
supported tracers; such as Datadog, Jaeger, Lightstep and Zipkin tracers.
Please note: tracers are not listed by any preference, but alphabetically.
The OT filter is a standard HAProxy filter, so what applies to others also
applies to this one (of course, by that I mean what is described in the
documentation, more precisely in the doc/internals/filters.txt file).
The OT filter activation is done explicitly by specifying it in the HAProxy
configuration. If this is not done, the OT filter in no way participates
in the work of HAProxy.
As for the impact on HAProxy speed, this is documented with several tests
located in the test directory, and the result is found in the README-speed-*
files. In short, the speed of operation depends on the way it is used and
the complexity of the configuration, from an almost immeasurable impact to
a significant deceleration (5x and more). I think that in some normal use
the speed of HAProxy with the filter on will be quite satisfactory with a
slowdown of less than 4%.
The OT filter allows intensive use of ACLs, which can be defined anywhere in
the configuration. Thus, it is possible to use the filter only for those
connections that are of interest to us.
More detailed documentation related to the operation, configuration and use
of the filter can be found in the contrib/opentracing directory.
To make the OpenTracing filter easier to configure and compile, several
entries have been added to the Makefile. When running the make utility,
it is possible to use several new arguments:
USE_OT=1 : enable the OpenTracing filter
OT_DEBUG=1 : compile the OpenTracing filter in debug mode
OT_INC=path : force the include path to libopentracing-c-wrapper
OT_LIB=path : force the lib path to libopentracing-c-wrapper
OT_RUNPATH=1 : add libopentracing-c-wrapper RUNPATH to haproxy executable
If USE_OT is set, then an additional Makefile from the contrib/opentracing
directory is included in the compilation process.
2020-12-09 15:54:31 +00:00
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#define FLT_OT_VAR_CHAR_DASH 'D'
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#define FLT_OT_VAR_CHAR_SPACE 'S'
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MAJOR: opentracing: reenable usage of vars to transmit opentracing context
Since commit 3a4bedccc ("MEDIUM: vars: replace the global name index with
a hash") the names of HAProxy variables are no longer saved, ie their
64-bit hashes are saved instead.
This is very convenient for the HAProxy itself, but for the OpenTracing
module it is a problem because the names of the variables are important
when transferring the OpenTracing context. Namely, this context consists
of an unknown amount of data stored in a key-value format. The number
of these data (and the name of the variable used for this purpose) is
determined with the configuration of the OpenTracing filter, as well as
with the tracer used. The two previous sentences seem to be in conflict,
but that is only so at first glance. The function in the OpenTracing
filter used to read the context does not really know this, neither their
number nor its name. The only thing that function actually knows is the
prefix of the variable names used for context transfer, and by that it
could find all the necessary data. Of course, until the application of
the above-mentioned commit.
The problem is solved in a very simple way: in a common variable that
the filter always knows its name, the names of all variables that are the
product of the OpenTracing context are saved. The names of these context
variables can only be added to that common variable. When that variable
is no longer needed (when we no longer need context), it is deleted.
The format for saving data to this common variable is as follows:
+-----+---------------+-- .. --+-----+---------------+
| len | variable name | | len | variable name |
+-----+---------------+-- .. --+-----+---------------+
The amount of memory space used to store the length of the name is 1 byte,
with a sign (the minus sign is provided for inactive records, but this is
not currently used). This means that the maximum length of the variable
name to be saved is 127 characters, which is quite enough for use in the
filter. The buffer size for such data storage is global.tune.bufsize.
This patch must be backported in 2.5.
2022-03-09 23:03:24 +00:00
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struct flt_ot_ctx {
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char value[BUFSIZ];
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int value_len;
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};
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typedef int (*flt_ot_ctx_loop_cb)(struct sample *, size_t, const char *, const char *, const char *, FLT_OT_VAR_CTX_SIZE, char **, void *);
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CONTRIB: opentracing: add the OpenTracing filter
This commit adds the OpenTracing filter (hereinafter we will use the
abbreviated name 'the OT filter') to the contrib tree.
The OT filter adds native support for using distributed tracing in HAProxy.
This is enabled by sending an OpenTracing compliant request to one of the
supported tracers; such as Datadog, Jaeger, Lightstep and Zipkin tracers.
Please note: tracers are not listed by any preference, but alphabetically.
The OT filter is a standard HAProxy filter, so what applies to others also
applies to this one (of course, by that I mean what is described in the
documentation, more precisely in the doc/internals/filters.txt file).
The OT filter activation is done explicitly by specifying it in the HAProxy
configuration. If this is not done, the OT filter in no way participates
in the work of HAProxy.
As for the impact on HAProxy speed, this is documented with several tests
located in the test directory, and the result is found in the README-speed-*
files. In short, the speed of operation depends on the way it is used and
the complexity of the configuration, from an almost immeasurable impact to
a significant deceleration (5x and more). I think that in some normal use
the speed of HAProxy with the filter on will be quite satisfactory with a
slowdown of less than 4%.
The OT filter allows intensive use of ACLs, which can be defined anywhere in
the configuration. Thus, it is possible to use the filter only for those
connections that are of interest to us.
More detailed documentation related to the operation, configuration and use
of the filter can be found in the contrib/opentracing directory.
To make the OpenTracing filter easier to configure and compile, several
entries have been added to the Makefile. When running the make utility,
it is possible to use several new arguments:
USE_OT=1 : enable the OpenTracing filter
OT_DEBUG=1 : compile the OpenTracing filter in debug mode
OT_INC=path : force the include path to libopentracing-c-wrapper
OT_LIB=path : force the lib path to libopentracing-c-wrapper
OT_RUNPATH=1 : add libopentracing-c-wrapper RUNPATH to haproxy executable
If USE_OT is set, then an additional Makefile from the contrib/opentracing
directory is included in the compilation process.
2020-12-09 15:54:31 +00:00
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#ifndef DEBUG_OT
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# define flt_ot_vars_dump(...) while (0)
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#else
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void flt_ot_vars_dump(struct stream *s);
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#endif
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int flt_ot_var_register(const char *scope, const char *prefix, const char *name, char **err);
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int flt_ot_var_set(struct stream *s, const char *scope, const char *prefix, const char *name, const char *value, uint opt, char **err);
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int flt_ot_vars_unset(struct stream *s, const char *scope, const char *prefix, uint opt, char **err);
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struct otc_text_map *flt_ot_vars_get(struct stream *s, const char *scope, const char *prefix, uint opt, char **err);
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#endif /* _OPENTRACING_VARS_H_ */
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/*
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* Local variables:
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* c-indent-level: 8
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* c-basic-offset: 8
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* End:
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*
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* vi: noexpandtab shiftwidth=8 tabstop=8
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*/
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