LTTng » LTTng-tools

The save command, when used to save a session containing a single log4j event and channel, produces empty stubs for all userspace domains.

<?xml version="1.0" encoding="UTF-8"?>
<sessions>
        <session>
                <name>test</name>
                <domains>
                        <domain>
                                <type>UST</type>
                                <buffer_type>PER_UID</buffer_type>
                                <channels/>
                                <trackers/>
                        </domain>
                        <domain>
                                <type>JUL</type>
                                <buffer_type>PER_UID</buffer_type>
                                <channels/>
                        </domain>
                        <domain>
                                <type>LOG4J</type>
                                <buffer_type>PER_UID</buffer_type>
                                <channels>
                                        <channel>
                                                <name>lttng_log4j_channel</name>
                                                <enabled>true</enabled>
                                                <overwrite_mode>DISCARD</overwrite_mode>
                                                <subbuffer_size>524288</subbuffer_size>
                                                <subbuffer_count>4</subbuffer_count>
                                                <switch_timer_interval>0</switch_timer_interval>
                                                <read_timer_interval>0</read_timer_interval>
                                                <output_type>MMAP</output_type>
                                                <tracefile_size>0</tracefile_size>
                                                <tracefile_count>0</tracefile_count>
                                                <live_timer_interval>0</live_timer_interval>
                                                <events>
                                                        <event>
                                                                <name>dfklasj</name>
                                                                <enabled>true</enabled>
                                                                <type>TRACEPOINT</type>
                                                                <loglevel_type>ALL</loglevel_type>
                                                                <filter>logger_name == &quot;dfklasj&quot;</filter>
                                                        </event>
                                                </events>
                                                <contexts/>
                                        </channel>
                                </channels>
                        </domain>
                        <domain>
                                <type>PYTHON</type>
                                <buffer_type>PER_UID</buffer_type>
                                <channels/>
                        </domain>
                </domains>
                <started>false</started>
                <output>
                        <consumer_output>
                                <enabled>true</enabled>
                                <destination>
                                        <path>/home/jgalar/lttng-traces/test-20170724-142342</path>
                                </destination>
                        </consumer_output>
                </output>
        </session>
</sessions>

Reproduction steps:

$ lttng create test
Session test created.
Traces will be written in /home/jgalar/lttng-traces/test-20170724-142342

$ lttng enable-channel -u lttng_log4j_channel --monitor-timer 456789
UST channel lttng_log4j_channel enabled for session test

$ lttng enable-event -l dfklasj
LOG4J event dfklasj enabled

$ lttng list test
Tracing session test: [inactive]
    Trace path: /home/jgalar/lttng-traces/test-20170724-142342

=== Domain: UST global ===

Buffer type: per UID

Channels:
-------------
- lttng_log4j_channel: [enabled]

    Attributes:
      overwrite mode: 0
      subbuffers size: 524288
      number of subbuffers: 4
      switch timer interval: 0
      read timer interval: 0
      monitor timer interval: 456789
      trace file count: 0
      trace file size (bytes): 0
      discarded events: 0
      lost packets: 0
      output: mmap()

    Events:
      None

=== Domain: LOG4j (Logging for Java) ===

Events (Logger name):
---------------------
    - dfklasj [enabled] [filter: 'logger_name == "dfklasj"']

$ lttng save
All sessions have been saved successfully.