уСТАРЕЛО (DEPRECATED)
Имя (Name)
DEPRECATED
lttng_health_check - Monitor health of the session daemon
Синопсис (Synopsis)
#include <lttng/lttng.h>
int lttng_health_check(enum lttng_health_component c);
Link with -llttng-ctl.
Описание (Description)
The lttng_health_check() is used to check the session daemon
health for either a specific component c or for all of them. Each
component represent a subsystem of the session daemon. Those
components are set with health counters that are atomically
incremented once reached. An even value indicates progress in the
execution of the component. An odd value means that the code has
entered a blocking state which is not a poll(7) wait period.
A bad health is defined by a fatal error code path reached or any
IPC used in the session daemon that was blocked for more than 20
seconds (default timeout). The condition for this bad health to
be detected is that one or many of the counters are odd.
The health check mechanism of the session daemon can only be
reached through the health socket which is a different one from
the command and the application socket. An isolated thread serves
this socket and only computes the health counters across the code
when asked by the lttng control library (using this call). This
subsystem is highly unlikely to fail due to its simplicity.
The c argument can be one of the following values:
LTTNG_HEALTH_CMD
Command subsystem which handles user commands coming from
the liblttng-ctl or the lttng(1) command line interface.
LTTNG_HEALTH_APP_MANAGE
The session daemon manages application socket in order to
route client command and check if they get closed which
indicates the application shutdown.
LTTNG_HEALTH_APP_REG
The application registration mechanism is an important and
vital part of for user space tracing. Upon startup,
applications instrumented with lttng-ust(3) try to
register to the session daemon through this subsystem.
LTTNG_HEALTH_KERNEL
Monitor the Kernel tracer streams and main channel of
communication (/proc/lttng). If this component
malfunction, the Kernel tracer is not usable anymore by
lttng-tools.
LTTNG_HEALTH_CONSUMER
The session daemon can spawn up to three consumer daemon
for kernel, user space 32 and 64 bit. This subsystem
monitors the consumer daemon(s). A bad health state means
that the consumer(s) are not usable anymore hence likely
making tracing not usable.
LTTNG_HEALTH_ALL
Check all components. If only one of them is in a bad
state, a health check error is returned.
Возвращаемое значение (Return value)
Return 0 if the health is OK, or 1 is it's in a bad state. A
return code of -1 indicates that the control library was not able
to connect to the session daemon health socket.
Ограничения (Limitations)
For the LTTNG_HEALTH_CONSUMER, you can not know which consumer
daemon has failed but only that either the consumer subsystem has
failed or that a lttng-consumerd died.
