Td Mxc Smf Roush

8/14/2019 Td Mxc Smf Roush

1/31

1

Let SMF Deal With That:

An introduction to theService ManagementFramework

Ellard RoushSun Microsystems

1


2/31

2

Agenda

Introduction to Service Management Framework(SMF)

Commands Demo Service Manifest and Development

Q&A


3/31

3

Service Management pre-SMF Daemons started by scripts delivered into /etc/rc*.d,

or by inetd (through /etc/inetd.conf)> Dependencies expressed through script numbering

(fragile, imprecise)

Common operations like stopping a service now &forever required two different steps> Easy to forget one> Often undone by patching or upgrade anyway

Daemon death ignored after start OS didn't know consequences of memory errors in

daemons had to panic


4/31

4

What is SMF?

It is solution to all the problems on the last slide

It is half of Predictive Self Healing>

It works with the Solaris Fault Manager to gracefullyrecover from uncorrectable hardware errors

It provides public, documented interfaces that ISVsand customers can use

It is used automatically> No need to turn it on> No way to turn it off


5/31

5

SMF basics:svc.startd

A new system daemon, svc.startd, has taken over mostofinit's responsibilities in starting system services

init still uses inittab, and /etc/rc*.d scripts are still run

svc.startd can automatically restart services> Ifsshd is enabled, then it is

started at boot

restarted if it dies (even if killed)

> sshd may be disabled by a single command stopped

not started at boot

not started after patch or upgrade


6/31

6

Service states

SMF lets the admin set whether each service isenabled or disabled

SMF keeps a state for each service

> uninitialized has not been evaluated yet

> disabled service is disabled, not running

> offline enabled, waiting for dependencies

> online enabled and running

> degraded running below full performance

> maintenance service problem occurred


7/317

Service dependencies Services may declare dependencies on each other

svc.startd starts services in dependency order

> Independent services started in parallel faster boot

Uncorrectable hardware errors handled better

> Daemon is restarted> Services which depend on it can be restarted

Enabled services hang out in the offline state until theirdependencies are met> A new command answers What services is service X

waiting for?


8/318

SMF configuration

Service meta-configuration(enabled status, state,dependencies, methods, etc.) iskept in the Service ConfigurationFacility (SCF), also known as the

SMF repository

The repository is controlled bysvc.configd, another newdaemon

The repository is (currently)stored in/etc/svc/repository.db

svc.startd

svc.configd

repository.db

SMF tools


9/319

Service names: FMRIs

Services are named by Fault Management ResourceIdentifiers, or FMRIs> URI syntax

svc:/system/cron:default

service name instancename

Note that while the service name usually contains slashes,

there are no service directories! The namespace is flat. Commands accept abbreviations (system/cron, cron)

and glob patterns


10/3110

Service instances

To allow configuration sharing,services are represented asinstance nodes which arechildren ofservice nodes

Both service nodes andinstance nodes can haveproperties

If an instance doesn't haveproperty X, the service'sproperty X is used

Dependencies on a service aresatisfied if any of its instancesare online

> Frees dependents from

knowing implementation

repository

service

instance

properties

properties

instance properties

service

service


11/3111

Commands:svcs(1)

$ svcsSTATE STIME FMRI....online 18:18:30 svc:/network/http:apache2online 18:18:29 svc:/network/smtp:sendmail....$ svcs -p sendmailSTATE STIME FMRIonline 18:18:29 svc:/network/smtp:sendmail

18:18:29 100180 sendmail18:18:29 100181 sendmail

$ svcs -d sendmailSTATE STIME FMRIonline 18:17:44 svc:/system/identity:domainonline 18:17:52 svc:/network/service:default

....

Without arguments, lists state, state-time, and FMRI ofservices that are enabled; with -a, lists all services

Show dependencies (-d) and dependents (-D)

Show member processes (-p), additional details (-v/-l)


12/3112

Commands:svcs -x

$ svcs telnet

STATE STIME FMRI

offline 7:38:17 svc:/network/telnet:default

$ svcs -x

svc:/network/inetd:default (inetd)

State: disabled since Wed Jan 25 07:38:17 2006

Reason: Disabled by an administrator.

See: http://sun.com/msg/SMF-8000-05

See: inetd(1M)

See: /var/svc/log/network-inetd:default.logImpact: 17 dependent services are not running. (Use -v for list.)

Answers the question: What's wrong with my system? Explains why services are offline, impact of non-running

services

Gives pointers to knowledge documents, log files to help

you determine the cause and find a remedy


13/3113

Commands:svcadm(1M) svcadm manipulates services

> svcadm enable enables services, services start whendependencies are ready

> svcadm disable disables services> svcadm restart stops and starts services>

svcadm refresh commits the current properties (to the runningsnapshot) and instructs the service to re-read its configuration> svcadm clear signals that a service in maintenance has been

fixed

These commands are asynchronous: they issue commands tosvc.startd and return immediately

With -s, enable & disable wait until completion (synchronous)

With -t, enable & disable are temporary (until next boot)


14/3114

Commands:svccfg(1M)

Interactive access to properties and snapshots

# svccfgsvc:> select network/http:apache2svc:/network/http:apache2> listprop...general frameworkgeneral/enabled boolean false...start methodstart/exec astring "/lib/svc/method/http-apache2 start"start/timeout_seconds count 60start/type astring methodsvc:/network/http:apache> editprop[ $EDITOR launches on a temporary file containing property settings ]svc:/network/http:apache2> exit# svcadm refresh apache2 # read latest configuration# svcadm restart apache2 # restart with latest configuration


15/3115

Commands Demo


16/3116

Troubleshooting

Service failures printed to console, syslog

Start with svcs -x output

> Often gives concise reason>

Provides link to knowledge document at sun.com> Gives path to log file

Use svcadm clear to clear maintenance state from repairedservices

Use svccfg to tweak debugging variables:> svccfg -s system/foo setenv LD_PRELOAD libumem.so

> svccfg -s system/foo setenv UMEM_DEBUG default


17/3117

Recovery

If a single service is broken, make sure you've got the latestservice config: svcadm refresh

Follow instructions from svcs -x pointer

Revert to a previous snapshot.

$ svccfg -s system/cron:defaultsvc:/system/cron:default> listsnapinitiallast-import

previousrunningstartsvc:/system/cron:default> revert startsvc:/system/cron:default> exit$ svcadm refresh cron$ svcadm restart cron


18/3118

Delegated Restarters svc.startd's model isn't right for all services (inetd, clustering)

SMF allows a service to be a delegated restarterfor otherservices> Start, stop, and refresh services however they want

> Responsible for managing instance states> svc.startd still handles enabledness & dependencies, though

inetd was reimplemented as a delegated restarter> Methods are called inetd_start, inetd_stop, etc.

> Services come online when inetd starts listening for them

> The repository is used for configuration instead ofinetd.conf

A public delegated restarter API is planned


19/3119

/etc/inetd.conf& inetadm(1M)

inetd.conf is no longer the primary configuration

Most Solaris inet services have been converted

Entries in inetd.conf are automatically convertedduring install & upgrade by inetconv(1M)

If something adds an entry to /etc/inetd.conf,inetd(1M) will detect and issue a warning message

> Run inetconv again to convert the new entry inetadm(1M) can be used to modify inetd-

specific properties


20/3120

Service Development: Benefits

Services appear with SMF FMRIs> Visible using standard Solaris tools; your service appears

in administrative heads-up displays

> Manageable using standard Solaris tools; admin canleverage existing knowledge to use your service

> New generic tools developed will automatically see yourservice

Built-in restart due to administrative error, software,or hardware fault

Participation in future software diagnosis

capabilities


21/3121

Service Development: Tasks

An existing Solaris service may be convertedincrementally, and to different levels

> Get it working: write a manifest using existing init script

as start/stop method> Handle error cases: refine methods

> Full restartability: if service has multiple components,split them into individual services

> Customized error/restart handling: avoid service restart iffault can be handled internally


22/3122

Service manifests

A service is delivered by an XML file called a manifest> Describes dependencies, methods, and properties

Manifests are delivered into /var/svc/manifest

During startup, new manifests in /var/svc/manifestand old manifests which have changed are loaded intothe repository with the svccfg(1M) command

Do not edit manifests in /var/svc/manifest; makecustomizations with svccfg(1M), etc.

> Repository customizations will be preserved acrosspatch & upgrade


23/31

23

Manifest Creation

Name your service

Identify whether your service may have multiple instances

Identify how your service is started/stopped

Determine faults to be ignored, if any

Identify dependencies

Identify dependents

Create at least one instance

Create template information to describe your service


24/31

24

Example Manifest: utmpd(1M)

utmpx monitoring


25/31

25

Method refinement

On failure, explain the problem to stdout orstderr (goes to a log) and exit with a non-0 code> If the failure is not transient, return$SMF_EXIT_ERR_FATAL or$SMF_EXIT_ERR_CONFIG

from /lib/svc/share/smf_include.sh

On success, don't return until service is ready toserve clients> Dependent services may be started immediately


26/31

26

Commands:svcprop(1)

List properties of services and instances

Fetch individual properties for use in scripts

$ svcprop network/http:apache2...physical/entities fmri svc:/network/physical:defaultphysical/grouping astring optional_allphysical/restart_on astring errorphysical/type astring servicestart/exec astring /lib/svc/method/http-apache2\ startstart/timeout_seconds count 60start/type astring methodstop/exec astring /lib/svc/method/http-apache2\ stopstop/timeout_seconds count 60stop/type astring methodrestarter/auxiliary_state astring nonerestarter/next_state astring nonerestarter/state astring disabledrestarter/state_timestamp time 1102030556.737590000$ svcprop -p enabled network/http:apache2false


27/31

27

Development: Other Examples

Manifest DTD is documented; read it at/usr/share/lib/xml/dtd/service_bundle.dtd.1

Explore /var/svc/manifest for similar services>

system/utmp is a simple standalone daemon> system/coreadm is a simple configuration service> network/telnet is an inetd-managed daemon

Explore /lib/svc/method for similar methods


28/31

28

Service Packaging

Use i.manifest and r.manifest from/usr/sadm/install/scripts

> (from S10U2 or OpenSolaris)

Manifests delivered into /var/svc/manifest withtype f and class manifest> Use /var/svc/manifest/site if the service is

specific to your site> Use another directory if you're an ISV, but remember a

uniquifier (e.g. stock ticker)

Methods delivered with your application binaries

(/opt strongly recommended)


29/31

29

Developer References

Manifest development> /usr/share/lib/xml/dtd/service_bundle.dtd.1

> Look in /var/svc/manifest for examples

> inetconv -i file to create an empty inetd manifest

> smf_method(5) information for writing methods

> inetd(1M) inetd-specific method information


30/31

30

Additional Resources

Discussion and further information athttp://opensolaris.org/os/community/smf Additional quickstart and developer documentation

available at

http://www.sun.com/bigadmin/content/selfheal/ Solaris System Administration Guide has SMF

information:http://docs.sun.com/app/docs/doc/817-1985

smf(5) manpage introduces the facility Blogs:

> http://blogs.sun.com/sch>

http://blogs.sun.com/lianep
http://opensolaris.org/os/community/smfhttp://www.sun.com/bigadmin/content/selfheal/http://docs.sun.com/app/docs/doc/817-1985http://blogs.sun.com/schhttp://blogs.sun.com/lianephttp://blogs.sun.com/lianephttp://blogs.sun.com/schhttp://docs.sun.com/app/docs/doc/817-1985http://www.sun.com/bigadmin/content/selfheal/http://opensolaris.org/os/community/smf


31/31

Let SMF Deal With That:

An introduction to theService ManagementFramework

Ellard Roush

Date post:	30-May-2018
Category:	Documents
Upload:	armandochagoya
View:	238 times
Download:	0 times

Td Mxc Smf Roush

Documents