High Volume Web API Managementwith WSO2 ESB

Paul FremantleCTO and Co-Founder

Hiranya Jayathilaka Associate Technical Lead

WSO2 Offerings

• WSO2 Carbon• On premise product platform• Consistent products sharing the same OSGi core

• WSO2 Stratos• A “Cloud-Enabled Application Platform” (CEAP)• Multi-tenant, Elastic, Metered/Billed deployment• An extension of the Carbon platform

• Same SVN code tree

• WSO2 StratosLive• http://stratoslive.wso2.com• A running Platform-as-a-Service (PaaS)• An instance of Stratos

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ForresterWave™ ESB Q2 2011 - Leader

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WSO2 ESB 4.0

WSO2 ESB Features

• The WSO2 Enterprise Service Bus offers:• Easy configuration through an intuitive graphical interface • Lean, high-performance design conserves resources

through maximum efficiency.• Built on the WSO2 Carbon OSGi platform: adding new

capabilities as you need them is a snap.• Integrates with your existing systems, with support for

EDI, CSV, Files, FIX, HL7, SAP, JMS, etc• Asynchronous architecture supports very high loads

with fixed resources• Routing, mediation and transformation are

modular, extensible but provide most use-cases simply by sequencing built-in mediators

• Full support for SOAP/WS-* and REST

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API Management Concerns

• Slow clients, IP denial of service, traffic shaping

• Security, authentication, authorization

• Monitoring, analytics and metrics

• Mediation, format translation, micro-orchestration

• Load-balancing, failover, routing

• Unification of multiple stacks

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API Management Concerns

• Slow clients, IP denial of service, traffic shaping• Non-blocking transport, priority execution, throttle/cache,

Message Relay Transport• Security, authentication, authorization

• Authn/Authz, SAML2, OAuth, XACML PEP• Monitoring, analytics and metrics

• Built-in metrics, JMX, WSO2 BAM Event Publisher• Mediation, format translation, micro-orchestration

• JSON support, SOAP<->JSON, Service chaining• Load-balancing, failover, routing

• Built in elastic load balancing, session-aware, failover• Unification of multiple stacks

• Lightweight proxy layer, CSG support

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eBay Case Study – High Volume

• Requirements:• “The solutions we were using no longer met our needs, so we considered

whether to build a new internal system or to adopt third-party technology”, Abhinav Kumar, eBay

• Needed enhanced service mediation and orchestration capabilities • Scalability and performance to sustain increasing loads

• Evaluation:• eBay evaluated several industry leading hardware and software ESB

solutions, looking at open source, commercially licensed ESBs and hardware

• Test production during 2009 holiday season proved that our system was rock solid

• 1m messages/day with zero downtime, zero memory growth• Results

• Shared-nothing architecture on RedHat Linux on x86 hardware• Currently running at more than 1 billion messages / day • Low resource utilization and flat memory usage

• The benefits• “Using the WSO2 ESBs, we've been able to provide customers and

partners with the quality experience they expect on eBay, even as our global customer base has grown,” Abhinav Kumar

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Memory Usage at eBay

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Deployment

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Configuring for High Volume

• Operating System • JVM• ESB• Management

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Tuning the OS

• Optimize core network settings for high throughput network activity• /etc/sysctl.conf

• Increase the number of open file descriptors allowed by the OS• /etc/security/limits.conf

Tuning the JVM

• Allocate sufficient memory for the heap • -Xms256m -Xmx2048m -

XX:MaxPermSize=256m• Consider reducing the new ratio

• -XX:NewRatio=n• Consider using the concurrent mark and

sweep collector• -XX:+UseConcMarkSweepGC

• Read more on JVM and GC tuning• http://wso2.org/library/articles/2010/11/

taming-java-garbage-collector

Tuning the ESB

• Configure transport thread pools• Configured through nhttp.properties file• IO dispatcher threads carry out network IO at

the wire level• Recommended to have one IO dispatcher per

CPU core

• Server workers and client workers mediate the messages• More the merrier (But keep memory usage

and load in mind)

Message Relay Mode

• WSO2 ESB uses Apache AXIOM and the StAX API for processing XML• XML payloads are streamed through the ESB• Pull parsing model

• But for pure routing, load-balancing and header-only mediation we can avoid even this step

• Message relay mode works around this glitch and enables 100% pure streaming of messages• Works regardless of size and format of messages

Enabling Message Relay

• Enable the binary relay builder (axis2.xml)• Instructs the ESB to stream the incoming messages through

without touching their payloads• Enable the expanding message formatter (axis2.xml)

• Allows the ESB to send messages that were received through the binary relay builder

<messageBuilder contentType="application/xml" class="org.wso2.carbon.relay.BinaryRelayBuilder"/>

<messageFormatter contentType="application/xml" class="org.wso2.carbon.relay.ExpandingMessageFormatter"/>

• Above configuration tells the ESB to process all application/xml messages in message relay mode.

HTTP Relay Transport

• Brand new in WSO2 ESB 4.0 release• Non blocking HTTP transport implementation

specially designed for streaming messages• Doesn’t require the binary relay builder and

expanding formatter• To enable, simply uncomment the relevant entries

in the axis2.xml file

Performance

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Error Handling

• In a large scale, high throughput deployment, errors are not unusual – Expect the unexpected

• Configure endpoints to gracefully handle the common errors• Connection timeouts• Connection close/reset• Connection refused• HTTP protocol violations!!!!

More on Error Handling

• Configure sequences to clearly log errors and if needed notify system administrators

• In case the back end server fails to respond, send detailed fault responses to clients – Makes your application more appealing to the customers

• Pay attention to HTTP error codes

Monitoring

• In general keep an eye on:• CPU usage• Memory usage• Thread counts• Fault counts• Latency/Response time• Active connections

Monitoring Tools

• Utilities Provided by OS• top• netstat

• Mediation statistics• JMX Clients

• Jconsole

Connections

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Endpoints

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Latency

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Listeners

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Memory and Garbage Collection

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S2S Latency

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Threads

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Questions?

30

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

Resources

• http://wso2.com/landing/ebay-the-esb-casestudy/• WSO2 ESB 4.0 Download and Library

• http://wso2.org/library/esb• Message Relay Mode

• http://wso2.org/project/esb/java/4.0.0/docs/message_relay.html

• Twitter: @pzfreo • Blogs:

• http://pzf.fremantle.org• http://techfeast-hiranya.blogspot.com/

• Email: paul@wso2.com hiranya@wso2.com

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