7 lttng-relayd - LTTng 2 relay daemon
13 *lttng-relayd* [option:--background | option:--daemonize]
14 [option:--control-port='URL'] [option:--data-port='URL'] [option:--live-port='URL']
15 [option:--output='PATH'] [option:-v | option:-vv | option:-vvv]
20 The http://lttng.org/[_Linux Trace Toolkit: next generation_] is an open
21 source software package used for correlated tracing of the Linux kernel,
22 user applications, and user libraries.
24 LTTng consists of Linux kernel modules (for Linux kernel tracing) and
25 dynamically loaded libraries (for user application and library tracing).
27 The _LTTng relay daemon_ is responsible for receiving trace data from
28 possibly remote LTTng session/consumer daemons and for writing it to
29 the local file system. The relay daemon also accepts _LTTng live_
30 connections from compatible viewers; this is the official approach to
31 viewing LTTng events as they are emitted.
33 The relay daemon listens by default on all network interfaces to gather
34 trace data, but only on localhost for LTTng live connections.
36 The relay daemon does not require any particular permissions, as long as
37 it can write to the output directory and listen on the configured ports.
38 If a user is within a secured network and/or has proper firewall
39 settings, `lttng-relayd` can listen to LTTng live connections from _all_
40 network interfaces by specifying `--live-port=tcp://0.0.0.0:5344`.
42 Once a trace has been streamed completely, the trace can be processed by
43 any tool that can process an LTTng trace located on the local
50 By default, the relay daemon writes the traces to:
53 $HOME/lttng-traces/'HOSTNAME'/'SESSION'/'DOMAIN'
66 You can override the default output directory prefix
67 (`$HOME/lttng-traces`) with the option:--output option. The other
68 parts depend on the remote configuration.
74 The option:--control-port, option:--data-port, and option:--live-port
77 The format of those URLs is:
80 tcp://('HOST' | 'IPADDR'):__PORT__
85 Binding hostname or IP address (IPv6 address *must* be enclosed in
86 brackets (`[` and `]`); see
87 https://www.ietf.org/rfc/rfc2732.txt[RFC 2732]).
97 option:-b, option:--background::
98 Start as Unix daemon, but keep file descriptors (console) open.
99 Use the option:--daemonize option instead to close the file
102 option:-d, option:--daemonize::
103 Start as Unix daemon, and close file descriptors (console). Use the
104 option:--background option instead to keep the file descriptors
107 option:-g, option:--group='GROUP'::
108 Use 'GROUP' as Unix tracing group (default: `tracing`).
110 option:-o, option:--output='PATH'::
111 Set base directory of written trace data to 'PATH'.
113 See the <<output-directory,Output directory>> section above for more
116 option:-v, option:--verbose::
119 Three levels of verbosity are available, which are triggered by
120 appending additional `v` letters to the option
121 (that is, `-vv` and `-vvv`).
126 See the <<url-format,URL format>> section above for more information
127 about the syntax of the following options' 'URL' argument.
129 option:-C, option:--control-port='URL'::
130 Listen to control data on URL 'URL' (default: `tcp://0.0.0.0:5342`).
132 option:-D, option:--data-port='URL'::
133 Listen to trace data on URL 'URL' (default: `tcp://0.0.0.0:5343`).
135 option:-L, option:--live-port='URL'::
136 Listen to LTTng live connections on URL 'URL'
137 (default: `tcp://0.0.0.0:5344`).
142 option:-h, option:--help::
145 option:-V, option:--version::
149 ENVIRONMENT VARIABLES
150 ---------------------
151 `LTTNG_NETWORK_SOCKET_TIMEOUT`::
152 Socket connection, receive and send timeout (milliseconds). A value
153 of 0 or -1 uses the timeout of the operating system (default).
155 `LTTNG_RELAYD_HEALTH`::
156 Path to relay daemon health's socket.
173 As of this version, only the TCP protocol is supported for both control
174 and data ports. In future versions, TCP will remain the sole available
175 protocol for control data since those communications are low-volume and
176 need absolute reliability; trace data could be carried over UDP.
178 For an unprivileged user running `lttng-relayd`, the maximum number of
179 file descriptors per process is usually 1024. This limits the number of
180 connections and opened trace files. This limit can be configured with
184 include::common-footer.txt[]
190 linklttng:lttng-sessiond(8),
191 linklttng:lttng-crash(1),
192 linklttng:lttng-ust(3),
193 linklttng:babeltrace(1)