SVC.STARTD(1M)SVC.STARTD(1M)NAMEsvc.startd - Service Management Facility master restarter
SYNOPSIS
/lib/svc/bin/svc.startd
svc:/system/svc/restarter:default
DESCRIPTIONsvc.startd is the master restarter daemon for Service Management Facil‐
ity (SMF) and the default restarter for all services. svc.startd
starts, stops, and restarts services based on administrative requests,
system failures, or application failures.
svc.startd maintains service state, as well as being responsible for
managing faults in accordance with the dependencies of each service.
svc.startd is invoked automatically during system startup. It is
restarted if any failures occur. svc.startd should never be invoked
directly.
See smf_restarter(5) for information on configuration and behavior com‐
mon to all restarters.
svcs(1) reports status for all services managed by the Service Configu‐
ration Facility. svcadm(1M) allows manipulation of service instances
with respect to the service's restarter.
Environment Variables
Environment variables with the "SMF_" prefix are reserved and may be
overwritten.
svc.startd supplies the "SMF_" environment variables specified in
smf_method(5) to the method. PATH is set to "/usr/sbin:/usr/bin" by
default. By default, all other environment variables supplied to
svc.startd are those inherited from init(1M).
Duplicate entries are reduced to a single entry. The value used is
undefined. Environment entries that are not prefixed with "<name>="
are ignored.
Restarter Options
svc.startd is not configured by command line options. Instead, configu‐
ration is read from the service configuration repository. You can use
svccfg(1M) to set all options and properties.
The following configuration variables in the options property group are
available to developers and administrators:
boot_messages
An astring (as defined in scf_value_is_type; see
scf_value_is_type(3SCF)) that describes the default level of mes‐
sages to print to the console during boot. The supported message
options include quiet and verbose. The quiet option prints minimal
messages to console during boot. The verbose option prints a single
message per service started to indicate success or failure. You can
use the boot -m option to override the boot_messages setting at
boot time. See kernel(1M).
logging
Control the level of global service logging for svc.startd. An
astring (as defined in scf_value_is_type; see
scf_value_is_type(3SCF)) that describes the default level of mes‐
sages to log to syslog (see syslog(3C) and svc.startd's global log‐
file, /var/svc/log/svc.startd.log. The supported message options
include quiet, verbose, and debug. The quiet option sends error
messages requiring administrative intervention to the console, sys‐
log and svc.startd's global logfile. The verbose option sends error
messages requiring administrative intervention to the console, sys‐
log and svc.startd's global logfile, and information about errors
which do not require administrative intervention to svc.startd's
global logfile. A single message per service started is also sent
to the console. The debug option sends svc.startd debug messages to
svc.startd's global logfile, error messages requiring administra‐
tive intervention to the console, syslog and svc.startd's global
logfile, and a single message per service started to the console.
milestone
An FMRI which determines the milestone used as the default boot
level. Acceptable options include only the major milestones:
svc:/milestone/single-user:default
svc:/milestone/multi-user:default
svc:/milestone/multi-user-server:default
or the special values all or none. all represents an idealized
milestone that depends on every service. none is a special mile‐
stone where no services are running apart from the master svc:/sys‐
tem/svc/restarter:default. By default, svc.startd uses all, a syn‐
thetic milestone that depends on every service. If this property is
specified, it overrides any initdefault setting in inittab(4).
system/reconfigure
Indicates that a reconfiguration reboot has been requested. Ser‐
vices with actions that must key off of a reconfiguration reboot
may check that this property exists and is set to 1 to confirm a
reconfiguration boot has been requested.
This property is managed by svc.startd and should not be modified
by the administrator.
Configuration errors, such as disabling svc.startd are logged by sys‐
log, but ignored.
SERVICE STATES
Services managed by svc.startd can appear in any of the states
described in smf(5). The state definitions are unmodified by this
restarter.
SERVICE REPORTING
In addition to any logging done by the managed service, svc.startd pro‐
vides a common set of service reporting and logging mechanisms.
Reporting properties svc.startd updates a common set of properties on
all services it manages. These properties are a common interface that
can be used to take action based on service instance health. The
svcs(1) command can be used to easily display these properties.
restarter/state
restarter/next_state
The current and next (if currently in transition) state for an
instance.
restarter/auxiliary_state
A caption detailing additional information about the current
instance state. The auxiliary state available for services managed
by svc.startd is:
maintenance
fault_threshold_reached
stop_method_failed
administrative_request
restarter/state_timestamp
The time when the current state was reached.
restarter/contract
The primary process contract ID, if any, that under which the ser‐
vice instance is executing.
Logs
By default, svc.startd provides logging of significant restarter
actions for the service as well as method standard output and standard
error file descriptors to /var/svc/log/service:instance.log. The level
of logging to system global locations like /var/svc/log/svc.startd.log
and syslog is controlled by the options/logging property.
SERVICE DEFINITION
When developing or configuring a service managed by svc.startd, a com‐
mon set of properties are used to affect the interaction between the
service instance and the restarter.
Methods
The general form of methods for the fork/exec model provided by
svc.startd are presented in smf_method(5). The following methods are
supported as required or optional by services managed by svc.startd.
refresh
Reload any appropriate configuration parameters from the
repository or config file, without interrupting service.
This is often implemented using SIGHUP for system daemons.
If the service is unable to recognize configuration changes
without a restart, no refresh method is provided.
This method is optional.
start
Start the service. Return success only after the application
is available to consumers. Fail if a conflicting instance is
already running, or if the service is unable to start.
This method is required.
stop
Stop the service. In some cases, the stop method can be
invoked when some or all of the service has already been
stopped. Only return an error if the service is not entirely
stopped on method return.
This method is required.
If the service does not need to take any action in a required method,
it must specify the :true token for that method.
svc.startd honors any method context specified for the service or any
specific method. The method expansion tokens described in smf_method(5)
are available for use in all methods invoked by svc.startd.
Properties
An overview of the general properties is available in smf(5). The spe‐
cific way in which these general properties interacts with svc.startd
follows:
general/enabled
If enabled is set to true, the restarter attempts to start the ser‐
vice once all its dependencies are satisfied. If set to false, the
service remains in the disabled state, not running.
general/restarter
If this FMRI property is empty or set to svc:/sys‐
tem/svc/restarter:default, the service is managed by svc.startd.
Otherwise, the restarter specified is responsible (once it is
available) for managing the service.
general/single_instance
If single_instance is set to true, svc.startd only allows one
instance of this service to transition to online or degraded at any
time.
Additionally, svc.startd managed services can define the optional prop‐
erties listed below in the startd property group.
startd/critical_failure_count
startd/critical_failure_period
The critical_failure_count and critical_failure_period properties
together specify the maximum number of service failures allowed in
a given number of seconds before svc.startd transitions the service
to maintenance. If the number of failures exceeds critical_fail‐
ure_count in any period of critical_failure_period seconds,
svc.startd will transition the service to maintenance. The criti‐
cal_failure_count value is limited to the range 1-10 and defaults
to 10. The critical_failure_period defaults to 600 seconds.
startd/duration
The duration property defines the service's model. It can be set to
transient, child also known as "wait" model services, or contract
(the default).
startd/ignore_error
The ignore_error property, if set, specifies a comma-separated list
of ignored events. Legitimate string values in that list are core
and signal. The default is to restart on all errors.
startd/need_session
The need_session property, if set to true, indicates that the
instance should be launched in its own session. The default is not
to do so.
startd/utmpx_prefix
The utmpx_prefix string property defines that the instance requires
a valid utmpx entry prior to start method execution. The default is
not to create a utmpx entry.
SERVICE FAILURE
svc.startd assumes that a method has failed if it returns a non-zero
exit code or if fails to complete before the timeout specified expires.
If $SMF_EXIT_ERR_CONFIG or $SMF_EXIT_ERR_FATAL is returned, svc.startd
immediately places the service in the maintenance state. For all other
failures, svc.startd places the service in the offline state. If a
service is offline and its dependencies are satisfied, svc.startd tries
again to start the service (see smf(5)).
If a contract or transient service does not return from its start
method before its defined timeout elapses, svc.startd sends a SIGKILL
to the method, and returns the service to the offline state.
If three failures happen in a row, or if the service is restarting more
than once a second, svc.startd places the service in the maintenance
state.
The conditions of service failure are defined by a combination of the
service model (defined by the startd/duration property) and the value
of the startd/ignore_error property.
A contract model service fails if any of the following conditions
occur:
o all processes in the service exit
o any processes in the service produce a core dump
o a process outside the service sends a service process a
fatal signal (for example, an administrator terminates a
service process with the pkill command)
The last two conditions may be ignored by the service by specifying
core and/or signal in startd/ignore_error.
Defining a service as transient means that svc.startd does not track
processes for that service. Thus, the potential faults described for
contract model services are not considered failures for transient ser‐
vices. A transient service only enters the maintenance state if one of
the method failure conditions occurs.
"Wait" model services are restarted whenever the child process associ‐
ated with the service exits. A child process that exits is not consid‐
ered an error for "wait" model services, and repeated failures do not
lead to a transition to maintenance state. However, a wait service
which is repeatedly exiting with an error that exceeds the default rate
(5 failures/second) will be throttled back so that the service only
restarts once per second.
LEGACY SERVICES
svc.startd continues to provide support for services invoked during the
startup run level transitions. Each /etc/rc?.d directory is processed
after all managed services which constitute the equivalent run level
milestone have transitioned to the online state. Standard init scripts
placed in the /etc/rc?.d directories are run in the order of their
sequence numbers.
The milestone to run-level mapping is:
milestone/single-user
Single-user (S)
milestone/multi-user
Multi-user (2)
milestone/multi-user-server
Multi-user with network services (3)
Additionally, svc.startd gives these legacy services visibility in SMF
by inserting an instance per script into the repository. These legacy
instances are visible using standard SMF interfaces such as svcs(1),
always appear in the LEGACY-RUN state, cannot be modified, and can not
be specified as dependencies of other services. The initial start time
of the legacy service is captured as a convenience for the administra‐
tor.
FILES
/var/svc/log
Directory where svc.startd stores log files.
/etc/svc/volatile
Directory where svc.startd stores log files in
early stages of boot, before /var is mounted read-
write.
EXAMPLE
Example 1 Turning on Verbose Logging
To turn on verbose logging, type the following:
# /usr/sbin/svccfg -s system/svc/restarter:default
svc:/system/svc/restarter:default> addpg options application
svc:/system/svc/restarter:default> setprop options/logging = \
astring: verbose
svc:/system/svc/restarter:default> exit
This request will take effect on the next restart of svc.startd.
SEE ALSOsvcs(1), svcprop(1), kernel(1M), init(1M), svcadm(1M), svccfg(1M),
svc.configd(1M), setsid(2), syslog(3C), libscf(3LIB),
scf_value_is_type(3SCF), contract(4), init.d(4), process(4), init‐
tab(4), attributes(5), smf(5), smf_method(5)
Aug 23, 2012 SVC.STARTD(1M)
