5 Most of the changes of LTTng 2.6 are bug fixes, making the toolchain
6 more stable than ever before. Still, LTTng 2.6 adds some interesting
9 LTTng 2.5 already supported the instrumentation and tracing of
10 [Java applications](#doc-java-application) through `java.util.logging`
11 (JUL). LTTng 2.6 goes one step further by supporting
12 <a href="https://logging.apache.org/log4j/1.2/" class="ext">Apache log4j 1.2</a>.
13 The new log4j domain is selected using the `--log4j` option in various
14 commands of the `lttng` tool.
16 LTTng-modules has supported system call tracing for a long time,
17 but until now, it was only possible to record either all of them,
18 or none of them. LTTng 2.6 allows the user to record only a specific
19 subset of system call events, e.g.:
22 lttng enable-event --kernel --syscall open,fork,chdir,pipe
25 Finally, the `lttng` command line tool cannot only communicate with
26 humans as it used to do, but also with machines thanks to its new
27 [machine interface](#doc-mi) feature.