Making Tomcat Multi-tenant, Elastic, Billed and Metered

Paul FremantleCTO and Co-Founder, WSO2

VP, Apache SynapseASF Member

@pzfreo http://pzf.fremantle.org

Afhkam AzeezLead Architect, Stratos

Axis2, Synapse PMCASF Member

And also big thanks to Shankar, Amila, Srinath, Isuru, Senaka and the whole team

Paul Fremantle

• Working in Apache since 2002

• Apache Member• CTO and Co-Founder of

WSO2• VP, Apache Synapse

• I play the Tin Whistle (in case you hadn’t noticed yet)

@tedleung

Ok I lied a bit

• This is about “Using Tomcat to run multi-tenanted, metered, elastic webapps”

• We didn’t embed this into Tomcat code• If you want to leave now, I won’t be

offended!

“Cloud Native”

• Self-service• Distributed and Elastic • Multi-tenant• Metered and Billed• Dynamically wired • Versionable, incrementally deployable and

testable

http://www.flickr.com/photos/ladymaggic/

http://www.flickr.com/photos/jurvetson/

Can I run Tomcat on the Cloud?

• Yes of course• There is at least one company selling

supported AMI images of Tomcat• What does that get me?

– Saves me creating an AMI• Can we do better? Yes!

Cloud computing in one page

The Big Picture• Infrastructure as a Service

– Servers, storage & networking– For infrastructure specialists

• Platform as a Service– Middleware and Core Services– For developers, integrators, architects

• Software as a Service– Applications– For end-users

© WSO2 2010

Enterprise IT in 2010

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© WSO2 2010

Enterprise IT in 2015+

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Stratos Application Server

What can I do with Stratos App Server?

• Deploy WAR files • Manage sessions

– Monitor– Expire

• Reload / Stop

A webapp, running in the cloud

Quick demo

Not just webapps – services too

• Supports deploying code as services– JAX-WS– Axis2 services– POJO– Spring-based POJO services

Uses Tomcat

• Running on Tomcat under OSGi• Multi-tenant• Metered• Elastic

How?

• How do we multi-tenant?

• How do we meter?

• How do we scale (elasticity)?

What Multi-tenancy ?

Many Parties shared same set of resources, while giving each an his own space

Challenges of Multi-tenancy

• Security and Data Isolation

• Allocation of resources

• Configuration, Management

• Programming Model

Multi-tenanting Tomcat

• http://appserver.cloud.wso2.com/t/fremantle.org/webapps/sample/

• Uses a valve to direct the request to the right tenant• WAR files already have separate classloaders

– And session isolation• Each tenant can only load code from their tenants deployed

WARs• For services we also restrict classloading using Java Security• We apply security policies to stop webapps opening ports,

modifying local files, calling OSGi Services– We intend to enhance this to support limited access to services

Multi-tenanting Axis2

Every tenant has access to an Identity Service

Identity

• Every domain/tenant has its own single-sign on and identity manager

• Based on LDAP – which is inherently multi-tenant– Each tenant has their own LDAP partition

• Supporting SAML2, OpenId, OAuth, XACML, Infocard, WS-Trust

Simply enabling security

<security-constraint><display-name>Example Security Constraint</display-name><web-resource-collection><!– some stuff deleted for simplicity--><login-config><auth-method>FORM</auth-method><realm-name>Example Form-Based Authentication Area</realm-name><form-login-config><form-login-page>/login.jsp</form-login-page><form-error-page>/login-error.jsp</form-error-page></form-login-config></login-config>

<!-- Security roles referenced by this web application --><security-role><role-name>admin</role-name></security-role>

Single sign-on

• We already support SAML2 based single-sign on for Administration– So if you want, you can use a SAML2 Relying Party in

your webapp, that works– We can recommend one too

• OpenSAML2 • https://spaces.internet2.edu/display/OpenSAML/Home/

• Not yet automatically supported for webapps– We plan to add this

Elasticity

• Elastic Load Balancer– Apache Synapse

• Always done load balancing• Now has full transparent HTTP support• Has “Autoscale” mediators

– Based on Azeez’s Master’s thesis• Priority Execution support and throttling (Business

Class)– Underlying Cloud API

• We have based on Amazon/Eucalyptus/Ubuntu API• Adding support for vmWare underneath

Overall plan

Apache Tribes

Distributed

• Our distribution/clustering model is based on Apache Tribes

• Adjusted Tribes to support WKA model• In a large cloud (e.g. Amazon) you cannot

rely on subnet communications between nodes

• Nominate two Well Known Addresses– Tribes contacts the WKA and uses that the

bootstrap the fabric

Performance Overhead of Multi-tenancy

Metering

Super tenant metering

Billing and Metering

• A generic multi-tenanted metering and billing module

• Written as OSGi• Uses Drools to implement service levels

– E.g. 10 users, 100Mb transfer/month, 15 deployed services for free level of subscription

• Can be used to meter real business events– How many sales transactions / month

Programming Model

• Sub-tenant programming model– “Normal”– Suited to fit within a tenant

• Super-tenant model– How to write one app for all tenants– i.e. how to write multi-tenant apps– Different but similar

• Neither is complete yet

Data

• Is a pain• Most webapps use JDBC-based data sources

– Very hard to “multi-tenant”• We are looking at two options:

– Multi-tenanted JBDC driver– Multi-tenant NoSQL (e.g. Cassandra)

• In Amazon environment you can start up RDS– But you pay for time not usage

Cache

• Uses JSR107• cache =

CarbonContext.getCurrentContext().getCache();• cache.put(key, value);• value = cache.get(key);

• CarbonContext is our general model for building a sub-tenant multi-tenant programming model– A set of standard stuff that works in an MT environment– Isolation and security

What else do you need?

• Multi-tenant enabled:– Log– Cache (done)– Billing– Identity – Authorization– JMS/Queue/Topics– Registry/Repository/Config access– Managed Service Requester (HTTP, SOAP)

• JAXWS/JAXRS/Commons HTTPClient

Summary

• Cloud Native attributes distinguish code that just floats on top of the cloud from applications that live in the cloud

• Stratos is an example of a making Tomcat Cloud Native

• Not complete…. But that would be boring anyway!