[lttng-dev] [PATCH lttng-tools 1/3] Metadata: add env fields to ease lttng path hierarchy creation for viewer
Jonathan Rajotte
jonathan.rajotte-julien at efficios.com
Tue Aug 13 14:26:49 EDT 2019
Add the following fields in the env section of the metadata:
- trace_name
The session name without datetime information.
Hence when the session is an auto-generated one, only print
LTTNG_DEFAULT_NAME.
- trace_creation_datetime:
The datetime at which the session was created.
We use session->creation time for it.
- tracer_buffering_scheme
The buffering scheme used. The value can be uid or pid.
- tracer_buffering_id
The key used by the buffering scheme (uid/pid).
- architecture_bit_width
The bit width of the computer architecture (e.g 32 or 64)
- vpid_datetime
The registration time of the vpid for per-pid mode.
Adding these fields ensure that the trace itself carry information that
is normally carried via folder hierarchy. e.g
test-20190417-174951/ <- trace_name, trace_creation_datetime
└── ust <- domain
└── uid <- tracer_buffering_scheme
└── 1000 <- tracer_buffering_id
└── 64-bit <- architecture_bit_width
├── channel0_0
├── index
│ ├── channel0_0.idx
└── metadata
Per-pid buffering is quite similar.
auto-20190722-174816 <- trace_name, trace_creation_datetime
└── ust <- domain
└── pid <- tracer_buffering_scheme
└── sample-ust-7640-20190722-174818 <- procname, tracer_buffering_id, vpid_datetime
├── my-channel_0
├── index
│ ├── my-channel_0.idx
├── metadata
Signed-off-by: Jonathan Rajotte <jonathan.rajotte-julien at efficios.com>
---
This should also be backported to 2.11 allowing Babeltrace 2 to merge
traces from archived data (rotation) and output a trace with a similar
lttng tree hierarchy.
---
src/bin/lttng-sessiond/ust-app.c | 5 +-
src/bin/lttng-sessiond/ust-metadata.c | 171 ++++++++++++++++++++++----
src/bin/lttng-sessiond/ust-registry.c | 7 +-
src/bin/lttng-sessiond/ust-registry.h | 18 ++-
src/common/time.c | 32 +++++
src/common/time.h | 9 ++
6 files changed, 215 insertions(+), 27 deletions(-)
diff --git a/src/bin/lttng-sessiond/ust-app.c b/src/bin/lttng-sessiond/ust-app.c
index 443232e79..8b3028c57 100644
--- a/src/bin/lttng-sessiond/ust-app.c
+++ b/src/bin/lttng-sessiond/ust-app.c
@@ -1990,7 +1990,7 @@ static int setup_buffer_reg_pid(struct ust_app_session *ua_sess,
app->byte_order, app->version.major,
app->version.minor, reg_pid->root_shm_path,
reg_pid->shm_path,
- ua_sess->euid, ua_sess->egid);
+ ua_sess->euid, ua_sess->egid, ua_sess->tracing_id, app->uid);
if (ret < 0) {
/*
* reg_pid->registry->reg.ust is NULL upon error, so we need to
@@ -2057,7 +2057,8 @@ static int setup_buffer_reg_uid(struct ltt_ust_session *usess,
app->uint64_t_alignment, app->long_alignment,
app->byte_order, app->version.major,
app->version.minor, reg_uid->root_shm_path,
- reg_uid->shm_path, usess->uid, usess->gid);
+ reg_uid->shm_path, usess->uid, usess->gid,
+ ua_sess->tracing_id, app->uid);
if (ret < 0) {
/*
* reg_uid->registry->reg.ust is NULL upon error, so we need to
diff --git a/src/bin/lttng-sessiond/ust-metadata.c b/src/bin/lttng-sessiond/ust-metadata.c
index a657f7c5d..2641c0be1 100644
--- a/src/bin/lttng-sessiond/ust-metadata.c
+++ b/src/bin/lttng-sessiond/ust-metadata.c
@@ -217,6 +217,41 @@ void sanitize_ctf_identifier(char *out, const char *in)
}
}
+static
+int print_escaped_ctf_string(struct ust_registry_session *session, const char *string)
+{
+ int ret;
+ size_t i;
+ char cur;
+
+ i = 0;
+ cur = string[i];
+ while (cur != '\0') {
+ switch (cur) {
+ case '\n':
+ ret = lttng_metadata_printf(session, "%s", "\\n");
+ break;
+ case '\\':
+ case '"':
+ ret = lttng_metadata_printf(session, "%c", '\\');
+ if (ret)
+ goto error;
+ /* We still print the current char */
+ /* Fallthrough */
+ default:
+ ret = lttng_metadata_printf(session, "%c", cur);
+ break;
+ }
+
+ if (ret)
+ goto error;
+
+ cur = string[++i];
+ }
+error:
+ return ret;
+}
+
/* Called with session registry mutex held. */
static
int ust_metadata_enum_statedump(struct ust_registry_session *session,
@@ -869,6 +904,104 @@ int64_t measure_clock_offset(void)
return offset_best_sample.offset;
}
+static
+int print_metadata_session_information(struct ust_registry_session *registry)
+{
+ int ret;
+ struct ltt_session *session = NULL;
+ char creation_datetime[ISO8601_LEN];
+
+ rcu_read_lock();
+ session = session_find_by_id(registry->tracing_id);
+ if (!session) {
+ ret = -1;
+ goto error;
+ }
+
+
+ /* Print the trace name */
+ ret = lttng_metadata_printf(registry, " trace_name = \"");
+ if (ret) {
+ goto error;
+ }
+
+ /*
+ * This is necessary since the creation time is present in the session
+ * name when it is generated.
+ */
+ if (session->has_auto_generated_name) {
+ ret = print_escaped_ctf_string(registry, DEFAULT_SESSION_NAME);
+ } else {
+ ret = print_escaped_ctf_string(registry, session->name);
+ }
+ if (ret) {
+ goto error;
+ }
+
+ ret = lttng_metadata_printf(registry, "\";\n");
+ if (ret) {
+ goto error;
+ }
+
+ /* Prepare creation time */
+ ret = time_t_to_ISO8601(creation_datetime, sizeof(creation_datetime),
+ session->creation_time);
+
+ if (ret) {
+ goto error;
+ }
+
+ /* Output the reste of the information */
+ ret = lttng_metadata_printf(registry,
+ " trace_creation_datetime = \"%s\";\n"
+ " hostname = \"%s\";\n",
+ creation_datetime,
+ session->hostname);
+ if (ret) {
+ goto error;
+ }
+
+error:
+ if (session) {
+ session_put(session);
+ }
+ rcu_read_unlock();
+ return ret;
+}
+
+static
+int print_metadata_app_information(struct ust_registry_session *registry,
+ struct ust_app *app)
+{
+ int ret;
+ char datetime[ISO8601_LEN];
+
+ if (!app) {
+ ret = 0;
+ goto end;
+ }
+
+ ret = time_t_to_ISO8601(datetime, sizeof(datetime),
+ app->registration_time);
+ if (ret) {
+ goto end;
+ }
+
+ ret = lttng_metadata_printf(registry,
+ " tracer_patchlevel = %u;\n"
+ " vpid = %d;\n"
+ " procname = \"%s\";\n"
+ " vpid_datetime = \"%s\";\n" ,
+ app->version.patchlevel,
+ (int) app->pid,
+ app->name,
+ datetime
+ );
+
+end:
+ return ret;
+}
+
/*
* Should be called with session registry mutex held.
*/
@@ -880,7 +1013,6 @@ int ust_metadata_session_statedump(struct ust_registry_session *session,
char uuid_s[UUID_STR_LEN],
clock_uuid_s[UUID_STR_LEN];
int ret = 0;
- char hostname[HOST_NAME_MAX];
assert(session);
@@ -930,41 +1062,36 @@ int ust_metadata_session_statedump(struct ust_registry_session *session,
if (ret)
goto end;
- /* ignore error, just use empty string if error. */
- hostname[0] = '\0';
- ret = gethostname(hostname, sizeof(hostname));
- if (ret && errno == ENAMETOOLONG)
- hostname[HOST_NAME_MAX - 1] = '\0';
ret = lttng_metadata_printf(session,
"env {\n"
- " hostname = \"%s\";\n"
" domain = \"ust\";\n"
" tracer_name = \"lttng-ust\";\n"
" tracer_major = %u;\n"
- " tracer_minor = %u;\n",
- hostname,
+ " tracer_minor = %u;\n"
+ " tracer_buffering_scheme = \"%s\";\n"
+ " tracer_buffering_id = %u;\n"
+ " architecture_bit_width = %u;\n",
major,
- minor
+ minor,
+ app ? "pid" : "uid",
+ app ? (int) app->pid : (int) session->tracing_uid,
+ session->bits_per_long
);
if (ret)
goto end;
+ ret = print_metadata_session_information(session);
+ if (ret)
+ goto end;
+
/*
* If per-application registry, we can output extra information
* about the application.
*/
- if (app) {
- ret = lttng_metadata_printf(session,
- " tracer_patchlevel = %u;\n"
- " vpid = %d;\n"
- " procname = \"%s\";\n",
- app->version.patchlevel,
- (int) app->pid,
- app->name
- );
- if (ret)
- goto end;
- }
+ ret = print_metadata_app_information(session, app);
+ if (ret)
+ goto end;
+
ret = lttng_metadata_printf(session,
"};\n\n"
diff --git a/src/bin/lttng-sessiond/ust-registry.c b/src/bin/lttng-sessiond/ust-registry.c
index a8db79ea6..c495d86b7 100644
--- a/src/bin/lttng-sessiond/ust-registry.c
+++ b/src/bin/lttng-sessiond/ust-registry.c
@@ -880,7 +880,9 @@ int ust_registry_session_init(struct ust_registry_session **sessionp,
const char *root_shm_path,
const char *shm_path,
uid_t euid,
- gid_t egid)
+ gid_t egid,
+ uint64_t tracing_id,
+ uid_t tracing_uid)
{
int ret;
struct ust_registry_session *session;
@@ -962,6 +964,9 @@ int ust_registry_session_init(struct ust_registry_session **sessionp,
goto error;
}
+ session->tracing_id = tracing_id;
+ session->tracing_uid = tracing_uid;
+
pthread_mutex_lock(&session->lock);
ret = ust_metadata_session_statedump(session, app, major, minor);
pthread_mutex_unlock(&session->lock);
diff --git a/src/bin/lttng-sessiond/ust-registry.h b/src/bin/lttng-sessiond/ust-registry.h
index 2940ab7ac..2fc2dff87 100644
--- a/src/bin/lttng-sessiond/ust-registry.h
+++ b/src/bin/lttng-sessiond/ust-registry.h
@@ -131,6 +131,10 @@ struct ust_registry_session {
*/
uint32_t major;
uint32_t minor;
+
+ /* The id of the parent session */
+ uint64_t tracing_id;
+ uid_t tracing_uid;
};
struct ust_registry_channel {
@@ -291,7 +295,9 @@ int ust_registry_session_init(struct ust_registry_session **sessionp,
const char *root_shm_path,
const char *shm_path,
uid_t euid,
- gid_t egid);
+ gid_t egid,
+ uint64_t tracing_id,
+ uid_t tracing_uid);
void ust_registry_session_destroy(struct ust_registry_session *session);
int ust_registry_create_event(struct ust_registry_session *session,
@@ -351,7 +357,15 @@ int ust_registry_session_init(struct ust_registry_session **sessionp,
uint32_t uint32_t_alignment,
uint32_t uint64_t_alignment,
uint32_t long_alignment,
- int byte_order)
+ int byte_order,
+ uint32_t major,
+ uint32_t minor,
+ const char *root_shm_path,
+ const char *shm_path,
+ uid_t euid,
+ gid_t egid,
+ uint64_t tracing_id,
+ uid_t tracing_uid);
{
return 0;
}
diff --git a/src/common/time.c b/src/common/time.c
index a01c16df5..387db3e32 100644
--- a/src/common/time.c
+++ b/src/common/time.c
@@ -16,6 +16,7 @@
*/
#include <common/time.h>
+#include <common/error.h>
#include <common/macros.h>
#include <stddef.h>
#include <stdint.h>
@@ -68,6 +69,37 @@ struct timespec timespec_abs_diff(struct timespec t1, struct timespec t2)
return res;
}
+LTTNG_HIDDEN
+int time_t_to_ISO8601(char *dest, size_t dest_size, time_t time)
+{
+ int ret;
+ struct tm tm, *timeinfo;
+
+ if (dest_size < ISO8601_LEN) {
+ ERR("Failed to format time to ISO8601 destination too small");
+ ret = -1;
+ goto end;
+ }
+
+ timeinfo = localtime_r(&time, &tm);
+ if (!timeinfo) {
+ PERROR("localtime");
+ ret = -1;
+ goto end;
+ }
+
+ ret = strftime(dest, dest_size, ISO8601_FORMAT, timeinfo);
+ if (ret == 0) {
+ ERR("Failed to format time to ISO8601");
+ ret = -1;
+ goto end;
+ }
+
+ ret = 0;
+end:
+ return ret;
+}
+
static
void __attribute__((constructor)) init_locale_utf8_support(void)
{
diff --git a/src/common/time.h b/src/common/time.h
index 24513d30b..5ea8c6628 100644
--- a/src/common/time.h
+++ b/src/common/time.h
@@ -46,6 +46,9 @@ bool locale_supports_utf8(void);
#define MIN_UNIT "m"
#define HR_UNIT "h"
+#define ISO8601_FORMAT "%Y%m%dT%H%M%S%z"
+#define ISO8601_LEN 26
+
/*
* timespec_to_ms: Convert timespec to milliseconds.
*
@@ -61,4 +64,10 @@ int timespec_to_ms(struct timespec ts, unsigned long *ms);
LTTNG_HIDDEN
struct timespec timespec_abs_diff(struct timespec ts_a, struct timespec ts_b);
+/*
+ * Format time_t to ISO8601 compatible format.
+ */
+LTTNG_HIDDEN
+int time_t_to_ISO8601(char *s, size_t s_size, time_t time);
+
#endif /* LTTNG_TIME_H */
--
2.17.1
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