Bug #606
closedlttng snapshot record can erroneously claim a successful snapshot
100%
Description
If a session is created with just the no-output
option, the snapshot
commands are possible, but they fail while giving the appearance of success:
$ sudo -H lttng create nooutmm --no-output Session nooutmm created. $ sudo -H lttng enable-channel channel0 --discard --output mmap -k Kernel channel channel0 enmabled for session nooutmm $ sudo -H lttng enable-event -k -a -c channel0 All kernel events are enabled in channel channel0 $ sudo -H lttng start Tracing started for session nooutmm $ sudo -H lttng snapshot record Snapshot recorded successfully for session nooutmm $ sudo -H lttng stop Waiting for data availability Tracing stopped for session nooutmm $ sudo -H lttng destroy -a Session nooutmm destroyed
Despite lttng reporting 'Snapshot recorded successfully for session nooutmm'
, no such capture occurs.
The lttng snapshot record
command also fails if the kernel events are using the splice
output mode (it is the default, after all), and again claims everything went okay. The log is essentially identical to that given above.
Updated by Daniel U. Thibault over 11 years ago
This (lack of actual output) only occurs if the lttng snapshot record
command does not have an URL argument (or -C and -D options).
Updated by Daniel U. Thibault over 11 years ago
If you lttng snapshot record URL
a session with splice
kernel channels, the URL/snapshot-x-yyymmdd-hhmmss-y/kernel/
path is created but it remains empty.
Updated by David Goulet about 11 years ago
- Project changed from LTTng to LTTng-tools
- Status changed from New to Confirmed
Updated by Mathieu Desnoyers about 11 years ago
- Status changed from Confirmed to Resolved
- % Done changed from 0 to 100
Applied in changeset b67578cb27784c08d36e0e445a81123ff507f835.