Automated self-testing and health checkof live Sling instances

Bertrand DelacrétazSling committer, ASF Member and (current) DirectorSenior Developer, Adobe CQ R&D team, Basel@bdelacretaz - grep.codeconsult.chadaptTo() Berlin, September 2013slides revision 2013-09-24

Sling health check tools - adaptTo() 2013 - Bertrand Delacretaz

How can you trust your current (fragile?) combination of OSGi bundles and configs?

It needs live TESTING.

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picture: anitapeppers on morgue!le.com

what do we mean by

Health Checks?

Sling health check tools - adaptTo() 2013 - Bertrand Delacretaz

HealthCheck APIs

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public interface HealthCheck { Result execute();}

public class Result { public boolean isOk() ... public Status getStatus() ... public Iterator<ResultLog.Entry> iterator() ...}

HealthCheckOSGi services

Service props:name, MBean, tags

Webconsole, JMX

Sling health check tools - adaptTo() 2013 - Bertrand Delacretaz

Webconsole plugin/system/console/healthcheck

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Sling health check tools - adaptTo() 2013 - Bertrand Delacretaz

Health Check MBeans

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Service propsname, MBean, tags

Sling health check tools - adaptTo() 2013 - Bertrand Delacretaz

Health Checks as JMX processors

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MBean

MBean

MBean

HC

HC

HC

using expressions likejmx.attribute('java.lang:type=ClassLoading', 'LoadedClassCount') > 10 && jmx.attribute('java.lang:type=Runtime', 'ManagementSpecVersion') > 1

Use cases

Sling health check tools - adaptTo() 2013 - Bertrand Delacretaz

Use cases

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System status Configuration

Self-testPerformance

All bundles up?Initial content ready?Disk space ok?External services ok?Load within bounds? (for jobs)

Requests per second ok?Request duration ok?Free memory ok?Replication queues ok?

Security checklist ok?Default accounts disabled?Demo content removed?

Startup smoke tests?Keep history of results?

what do you get

Out of the box?

Sling health check tools - adaptTo() 2013 - Bertrand Delacretaz

Out of the box - core

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JmxAttributeHealthCheck

ScriptableHealthCheck

CompositeHealthCheck

Single JMX attributes

Script(let)s in any languageusing BindingValuesProviders

Run other Health Checksbased on their tags

Sling health check tools - adaptTo() 2013 - Bertrand Delacretaz

Out of the box - support bundle

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SlingRequestStatusHC

DefaultLoginsHealthCheck

Is my resource there?Including its scripts?

admin:admin -> fail?

current HC bundles:org.apache.sling.hc.coreorg.apache.sling.hc.supportorg.apache.sling.hc.webconsoleorg.apache.sling.hc.jmxorg.apache.sling.hc.samples

how do you write

Your own Health Checks?

Sling health check tools - adaptTo() 2013 - Bertrand Delacretaz

Custom Health Checks

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@Component(...policy=ConfigurationPolicy.REQUIRE, metatype=true)@Property(name=HealthCheck.NAME),@Property(name=HealthCheck.TAGS,unbounded=PropertyUnbounded.ARRAY),@Property(name=HealthCheck.MBEAN_NAME)@Service(value=HealthCheck.class)public class MyHealthCheck { public Result execute() { FormattingResultLog f = new FormattingResultLog(); ... if(badThings) f.warn(“Something happened with {}”, foo); return new Result(f); }}

Execute “quickly”, cache...

Sling health check tools - adaptTo() 2013 - Bertrand Delacretaz

That’s it - have fun!

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JmxAttributeHealthCheck

ScriptableHealthCheck

CompositeHealthCheck

SlingRequestStatusHC

DefaultLoginsHealthCheck

@Service(value=HealthCheck.class)public class MyHealthCheck { ....generate a Result quickly}

Docs at sling.apache.org : bundles : health check.Discuss on the Sling dev list.

I’m @bdelacretaz - thanks!

JMX processors

Webconsole

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