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.
diff --git a/contrib/opentracing/test/be/cfg-dd.json b/contrib/opentracing/test/be/cfg-dd.json
new file mode 100644
index 0000000..8b69b03
--- /dev/null
+++ b/contrib/opentracing/test/be/cfg-dd.json
@@ -0,0 +1,5 @@
+{
+ "service": "BE",
+ "agent_host": "localhost",
+ "agent_port": 8126
+}
diff --git a/contrib/opentracing/test/be/cfg-jaeger.yml b/contrib/opentracing/test/be/cfg-jaeger.yml
new file mode 100644
index 0000000..0893166
--- /dev/null
+++ b/contrib/opentracing/test/be/cfg-jaeger.yml
@@ -0,0 +1,34 @@
+service_name:
+ BE
+
+###
+# When using configuration object to instantiate the tracer, the type of
+# sampling can be selected via sampler.type and sampler.param properties.
+# Jaeger libraries support the following samplers:
+#
+# - Constant (sampler.type=const) sampler always makes the same decision for
+# all traces. It either samples all traces (sampler.param=1) or none of
+# them (sampler.param=0).
+#
+# - Probabilistic (sampler.type=probabilistic) sampler makes a random sampling
+# decision with the probability of sampling equal to the value of
+# sampler.param property. For example, with sampler.param=0.1 approximately
+# 1 in 10 traces will be sampled.
+#
+# - Rate Limiting (sampler.type=ratelimiting) sampler uses a leaky bucket rate
+# limiter to ensure that traces are sampled with a certain constant rate.
+# For example, when sampler.param=2.0 it will sample requests with the rate
+# of 2 traces per second.
+#
+# - Remote (sampler.type=remote, which is also the default) sampler consults
+# Jaeger agent for the appropriate sampling strategy to use in the current
+# service. This allows controlling the sampling strategies in the services
+# from a central configuration in Jaeger backend, or even dynamically.
+#
+sampler:
+ type: ratelimiting
+ param: 10.0
+
+reporter:
+ logSpans: true
+ localAgentHostPort: localhost:6831
diff --git a/contrib/opentracing/test/be/cfg-zipkin.json b/contrib/opentracing/test/be/cfg-zipkin.json
new file mode 100644
index 0000000..f0e30d5
--- /dev/null
+++ b/contrib/opentracing/test/be/cfg-zipkin.json
@@ -0,0 +1,4 @@
+{
+ "service_name": "BE",
+ "collector_host": "localhost"
+}
diff --git a/contrib/opentracing/test/be/haproxy.cfg b/contrib/opentracing/test/be/haproxy.cfg
new file mode 100644
index 0000000..c225a2f
--- /dev/null
+++ b/contrib/opentracing/test/be/haproxy.cfg
@@ -0,0 +1,37 @@
+global
+# nbthread 1
+ maxconn 5000
+ hard-stop-after 10s
+# log localhost:514 local7 debug
+# debug
+ stats socket /tmp/haproxy-be.sock mode 666 level admin
+
+defaults
+ log global
+ mode http
+ option httplog
+ option dontlognull
+ option httpclose
+ retries 3
+ maxconn 4000
+ timeout connect 5000
+ timeout client 50000
+ timeout server 50000
+
+listen stats
+ mode http
+ bind *:8002
+ stats uri /
+ stats admin if TRUE
+ stats refresh 10s
+
+frontend ot-test-be-frontend
+ bind *:11080
+ mode http
+ default_backend servers-backend
+
+ filter opentracing id ot-test-be config be/ot.cfg
+
+backend servers-backend
+ mode http
+ server server-1 127.0.0.1:8000
diff --git a/contrib/opentracing/test/be/ot.cfg b/contrib/opentracing/test/be/ot.cfg
new file mode 100644
index 0000000..edd3f76
--- /dev/null
+++ b/contrib/opentracing/test/be/ot.cfg
@@ -0,0 +1,62 @@
+[ot-test-be]
+ ot-tracer ot-test-tracer
+ config be/cfg-jaeger.yml
+ plugin libjaeger_opentracing_plugin-0.5.0.so
+# log localhost:514 local7 debug
+ option dontlog-normal
+ option hard-errors
+ no option disabled
+
+ scopes frontend_http_request
+ scopes backend_tcp_request
+ scopes backend_http_request
+ scopes client_session_end
+
+ scopes server_session_start
+ scopes tcp_response
+ scopes http_response
+ scopes server_session_end
+
+ ot-scope frontend_http_request
+ extract "ot-ctx" use-headers
+ span "HAProxy session" child-of "ot-ctx" root
+ baggage "haproxy_id" var(sess.ot.uuid)
+ span "Client session" child-of "HAProxy session"
+ span "Frontend HTTP request" child-of "Client session"
+ tag "http.method" method
+ tag "http.url" url
+ tag "http.version" str("HTTP/") req.ver
+ event on-frontend-http-request
+
+ ot-scope backend_tcp_request
+ span "Backend TCP request" follows-from "Frontend HTTP request"
+ finish "Frontend HTTP request"
+ event on-backend-tcp-request
+
+ ot-scope backend_http_request
+ span "Backend HTTP request" follows-from "Backend TCP request"
+ finish "Backend TCP request"
+ event on-backend-http-request
+
+ ot-scope client_session_end
+ finish "Client session"
+ event on-client-session-end
+
+ ot-scope server_session_start
+ span "Server session" child-of "HAProxy session"
+ finish "Backend HTTP request"
+ event on-server-session-start
+
+ ot-scope tcp_response
+ span "TCP response" child-of "Server session"
+ event on-tcp-response
+
+ ot-scope http_response
+ span "HTTP response" follows-from "TCP response"
+ tag "http.status_code" status
+ finish "TCP response"
+ event on-http-response
+
+ ot-scope server_session_end
+ finish *
+ event on-server-session-end