[lttng-dev] [RFC PATCH lttng-tools v2] Fix: path of snapshots with a relay and default URI

[Jérémie Galarneau]

Merged, thanks!

Jérémie

On 30 August 2017 at 14:06, Julien Desfossez <jdesfossez at efficios.com> wrote:
> When recording a snapshot to a relay without custom URI (ex:
> net://localhost vs net://localhost/custom), the snapshots end up being
> stored in ~/lttng-traces/<hostname>/snapshot-XXX instead of being inside
> the <session-name> folder like on local snapshots. We would expect the
> path to be: ~/lttng-traces/<hostname>/<session-name>/snapshot-XXX
>
> So there is a discrepancy between the local and remote behaviour. This
> behaviour has been there since at least v2.6, maybe earlier.
>
> Moreover, there is nothing that informs the user about the default
> snapshot name, so it is not possible to know where a snapshot has been
> stored.
>
> After parsing the URI provided by the user, we now check if a custom
> name was provided or copy the session name there. This is the same
> operation performed in _lttng_create_session_ext.
>
> Signed-off-by: Julien Desfossez <jdesfossez at efficios.com>
> ---
>  src/lib/lttng-ctl/lttng-ctl.c | 13 +++++++++++++
>  1 file changed, 13 insertions(+)
>
> diff --git a/src/lib/lttng-ctl/lttng-ctl.c b/src/lib/lttng-ctl/lttng-ctl.c
> index a1e10f2..3db9b89 100644
> --- a/src/lib/lttng-ctl/lttng-ctl.c
> +++ b/src/lib/lttng-ctl/lttng-ctl.c
> @@ -2485,9 +2485,22 @@ int lttng_create_session_snapshot(const char *name, const char *snapshot_url)
>
>         lsm.u.uri.size = size;
>
> +       /*
> +        * If the user does not specify a custom subdir, use the session name.
> +        */
> +       if (size > 0 && uris[0].dtype != LTTNG_DST_PATH && strlen(uris[0].subdir) == 0) {
> +               ret = snprintf(uris[0].subdir, sizeof(uris[0].subdir), "%s", name);
> +               if (ret < 0) {
> +                       PERROR("snprintf uri subdir");
> +                       ret = -LTTNG_ERR_FATAL;
> +                       goto error;
> +               }
> +       }
> +
>         ret = lttng_ctl_ask_sessiond_varlen_no_cmd_header(&lsm, uris,
>                         sizeof(struct lttng_uri) * size, NULL);
>
> +error:
>         free(uris);
>         return ret;
>  }
> --
> 2.7.4
>



-- 
Jérémie Galarneau
EfficiOS Inc.
http://www.efficios.com