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The Enterprise Service Bus
Introduction using Mule
By
Tharun yadav
1
Agenda
 What is Mule?
 How do you use Mule?
 What are the core Mule concepts?
 Learning mule with File endpoints
2
Enterprise Service Backbone
 Mule is an open-source Enterprise Service Backbone (ESB)
3
Mule is Has Advanced
Technologies
 SEDA
 Staged Event-Driven Architecture
 Java NIO
 Java New Input/Output
4
SEDA
 SEDA decomposes a complex, event-driven software application
into a set of stages connected by queues
 This design avoids the high overhead associated with thread-based
concurrency models, and decouples event and thread scheduling
from application logic
 By performing admission control on each event queue, the service
can be well-conditioned to load, preventing resources from being
overcommitted when demand exceeds service capacity
 SEDA employs dynamic control to automatically tune runtime
parameters (such as the scheduling parameters of each stage) as
well as to manage load, for example, by performing adaptive load
shedding
 Decomposing services into a set of stages also enables modularity
and code reuse, as well as the development of debugging tools for
complex event-driven applications
5
Java NIO
 NIO is a collection of Java programming language APIs that
offer advanced features for intensive I/O operations
 NIO facilitates an implementations that can directly use
the most efficient operations of the underlying platform
 NIO includes:
 Buffers for data of primitive types
 Character set encoders and decoders
 A pattern-matching facility based on Perl-style regular expressions
(in package java.util.regex)
 Channels, a new primitive I/O abstraction
 A file interface that supports locks and memory mapping
 A multiplexed, non-blocking I/O facility for writing scalable servers
6
Mule’s “Moves Things
Around”
 Folder to folder
 Queue to queue
 Shared memory to shared memory
 Using different types of transports
 In a flexible way
7
XML Pipeline
 An XML pipeline is a series of operation that are
performed on one or more XML files
 Examples include:
 validate
 transform
 prune (remove nodes)
 split (break a single XML file into many files)
 merge (join two or more files together)
8
CRV Example
 Flow of XML document through approval processes
9
Submit
CRV
Deed
Matched
CRV
SSN
Stripped
CRV
Income
Tax
Audit
County
Audit
County
Approval
State
Audit
State
Approval
Decomposition
 Example of XML Operations used on CRV
10
Validate Split
Remove
SSN
Element
Store
Modify
Value
Add
Element
Modify
Value
Add
Element
Declarative Approach
 Focus on specifying "What" not "How"
 Empower business analysis to write machine-readable
specifications
 Hide the "How" behind services with clear interfaces
(SOA)
11
Core Mule Concepts
 Mule Manager
 Mule Model
 Universal Message Object (UMO)
 Endpoints
 External Applications
12
Universal Message Object
(UMO)
 A UMO is a type of Java object that can
 receive events "from anywhere"
 send events
 UMO Components are usually your
business objects. They are components
that execute business logic on an
incoming event
 UMO are standard JavaBeans (containers)
 There is no Mule-specific code in your
components
 Mule handles all routing and
transformation of events to and from your
objects based on the configuration of your
component
13
Transport
 A transport or "provider", is a set of objects that add
support to Mule to handle a specific kind of transport or
protocol
 Examples
 the "Email Provider" enables Mule to send and receive
messages via the SMTP, POP and IMAP protocols
14
Connector
 A connector is the object that sends and receives
messages on behalf of an endpoint.
 Connectors are bundled as part of specific transports or
providers.
 For example, the FileConnector can read and write
file system files.
15
Router
 A router is the object that do something with messages
once they have been received by a connector, or prior
to being sent out by the connector
16
Filter
 A filter optionally filters incoming or
outgoing messages that are coming
into or going out from a connector.
 For example, the File Provider comes
with a FilenameWildcardFilter
that restricts which files are read by
the connector based on file name
patterns. For example only files with
the .xml extension can be routed.
 Filters are used in conjunction with
Routers.
17
Transformer
 A transformer optionally changes incoming or outgoing
messages in some way
 This is usually done to make the message format
useable by a downstream function
 Examples:
 the ByteArrayToString transformer converts byte arrays
into String objects.
18
Mule Event Flow
 The nine stages of a mule event
 first 2 – inbound
 middle 4 – component
 last 2 – outbound
19
Endpoint
(Message Receiver)
Endpoint
(Message Dispatcher)
Inbound Router
Outbound Router
Inbound Transformer
Outbound Transformer
Interceptor
Service Invocation
Interceptor
Inbound
Component
Outbound
Optional Step
Message Receiver Endpoint
 Some event triggers a message flow
 A file being written into a folder
 A message arriving on a message queue
 A record in a database
 Data written to a socket
20
Endpoint
(Message Dispatcher)
Inbound Router
Outbound Router
Inbound Transformer
Outbound Transformer
Interceptor
Service Invocation
Interceptor
Endpoint
(Message Receiver)
Inbound Router
 The inbound router is the fist step
in a message. Functions typically
performed by an inbound router
 Filtering
 Remove duplicate messages
 Matching messages
 Aggregation (combining)
 Re-sequence data
 Forwarding
 See also
 IdempotentReceiver
 CorrolationAggregator
 CorrelationResequencer
21
Endpoint
(Message Dispatcher)
Inbound Router
Outbound Router
Inbound Transformer
Outbound Transformer
Interceptor
Service Invocation
Interceptor
Endpoint
(Message Receiver)
Interceptor
 Used to intercept message
flow into your service
component
 Used trigger monitor/events
or interrupt the flow of the
message
 Example: an authorization
interceptor could ensure that
the current request has the
correct credentials to invoke
the service.
22
Endpoint
(Message Dispatcher)
Inbound Router
Outbound Router
Inbound Transformer
Outbound Transformer
Service Invocation
Interceptor
Endpoint
(Message Receiver)
Interceptor
Inbound Transformer
 If the inbound data is not in the
correct format for the service it
must be transformed at this point
23
Endpoint
(Message Receiver)
Endpoint
(Message Dispatcher)
Inbound Router
Outbound Router
Outbound Transformer
Interceptor
Service Invocation
Interceptor
Inbound Transformer
Service Invocation
 The actual service is performed
 In mule, this is generally a Java object
 Service invocation can also be a "pass
through"
24
Endpoint
(Message Receiver)
Endpoint
(Message Dispatcher)
Inbound Router
Outbound Router
Outbound Transformer
Interceptor
Interceptor
Inbound Transformer
Service Invocation
Outbound Router
 Dispatching the data to all the
relevant endpoints
25
Endpoint
(Message Receiver)
Endpoint
(Message Dispatcher)
Inbound Router
Outbound Transformer
Interceptor
Interceptor
Inbound Transformer
Service Invocation
Outbound Router
Built-in Router Classes
Inbound Outbound Response
Idempotent Receiver Filtering Outbound Router Response Aggregator
Selective Consumer Recipient List
Aggregator Multicasting Router
Resequencer Chaining Router
Forwarding Consumer Message Splitter
Filtering List Message
Splitter
Filtering Xml Message
Splitter
Exception Based Router
26
Outbound Transformer
 Any transformations that needs
to be done on the message after
a service has been performed on
the message can be executed
before it is put into the endpoint
 See Also
 EnvelopeInterceptor
27
Endpoint
(Message Receiver)
Endpoint
(Message Dispatcher)
Inbound Router
Interceptor
Interceptor
Inbound Transformer
Service Invocation
Outbound Router
Outbound Transformer
Test Environment
28
Omitted From Examples
for Brevity<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE mule-configuration PUBLIC "-//MuleSource
//DTD mule-configuration XML V1.0//EN"
"http://mule.mulesource.org/dtds/mule-
configuration.dtd">
29
Outline of Move All Files
<mule-configuration>
<model>
<mule-descriptor>
<inbound-router>
<endpoint
address="file:///c:/mule-class/in"/>
</inbound-router>
<outbound-router>
<router>
<endpoint
address="file:///c:/mule-class/out"/>
</router>
</outbound-router>
</mule-descriptor>
</model>
</mule-configuration>
30
Move All Files – Procedural
Details
<mule-configuration id="Mule_File_Move" version=" 1.0">
<connector name="SystemStreamConnector"
className="org.mule.providers.stream.SystemStreamConnector"/>
<model name="move-all-files">
<mule-descriptor name="move-file"
implementation="org.mule.components.simple.BridgeComponent">
<inbound-router>
<endpoint address="file:///c:/tmp/in"/>
</inbound-router>
<outbound-router>
<router
className="org.mule.routing.outbound.OutboundPassThroughRouter">
<endpoint address="file:///c:/tmp/out"/>
</router>
</outbound-router>
</mule-descriptor>
</model>
</mule-configuration>
31
Only Moving XML Files
<inbound-router>
<endpoint address="file:///c:/mule-class/in">
<filter pattern="*.xml"
className=
"org.mule.providers.file.filters.FilenameWildcardFilter"/>
</endpoint>
</inbound-router>
32
Add the filter line to only move files with the extension
"*.xml". If you add a file "foobar.txt to the input folder it
will not be moved.
Keeping the Name The Same
<outbound-router>
<router className="org.mule.routing.outbound.OutboundPassThroughRouter">
<endpoint
address=
"file:///c:/mule-class/out?outputPattern=$[ORIGINALNAME]"
/>
</router>
</outbound-router>
33
Add the outputPattern parameter to keep the output
name the same as the input.
Happy Path and Exceptions
 By default, error free documents follow a central path
known as the "happy path"
 Documents that have errors may be handled in different
ways (rejected, warnings etc.)
34
Start StopStep 1 Step 2 Step 3
Stop Stop Stop
Exception Handling
 Mule has a special way of handling non-happy path processing.
This is called an "Exception Strategy" but is it really just and
exception path and there is very little strategy involved.
 There are three places you can associate an exception strategy
 connector
 component
 model (set for all components in a model)
35
Exception Strategy
<exception-strategy
className=org.mule.impl.DefaultComponentExceptionStrategy">
<endpoint address="file:///c:/mule-class/error"/>
</exception-strategy>
36
We want all invalid documents to be moved into the
error folder.
Sample XML
<?xml version="1.0" encoding="UTF-8"?>
<Data>
<Element1>Hello World!</Element1>
<Element2>String</Element2>
<Element3>String</Element3>
<DansInvalidDataElement>This is Dans invalid data element</DansInvalidDataElement>
</Data>
37
XML Schema validation will generate an error message
when it gets to the fourth invalid data element:
Given the following XML Schema file:
Validating against an XML
Schema<outbound-router>
<router className="org.mule.routing.outbound.FilteringXmlMessageSplitter">
<endpoint
address="file:///c:/mule-class/out?outputPattern=$[ORIGINALNAME]"/>
<properties>
<property name="validateSchema" value="true"/>
<property name="externalSchemaLocation"
value="file:///c:/mule-class/labs/07-validate/my-schema.xsd"/>
</properties>
</router>
</outbound-router>
38
To validate the XML Schema, just add two properties:
1) tell it to validate the document
2) tell it what file to use and where to find it
Error Message
document : cvc-complex-type.2.4.d: Invalid content was found
starting with element 'DansInvalidDataElement'. No child
element is expected at this point.
39
This error message is generated on the Mule console
when an invalid data element is found. But what should
we do with it? How do we redirect it to the appropriate
user?
Thank You!
40

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Mulesoftppt

  • 1. The Enterprise Service Bus Introduction using Mule By Tharun yadav 1
  • 2. Agenda  What is Mule?  How do you use Mule?  What are the core Mule concepts?  Learning mule with File endpoints 2
  • 3. Enterprise Service Backbone  Mule is an open-source Enterprise Service Backbone (ESB) 3
  • 4. Mule is Has Advanced Technologies  SEDA  Staged Event-Driven Architecture  Java NIO  Java New Input/Output 4
  • 5. SEDA  SEDA decomposes a complex, event-driven software application into a set of stages connected by queues  This design avoids the high overhead associated with thread-based concurrency models, and decouples event and thread scheduling from application logic  By performing admission control on each event queue, the service can be well-conditioned to load, preventing resources from being overcommitted when demand exceeds service capacity  SEDA employs dynamic control to automatically tune runtime parameters (such as the scheduling parameters of each stage) as well as to manage load, for example, by performing adaptive load shedding  Decomposing services into a set of stages also enables modularity and code reuse, as well as the development of debugging tools for complex event-driven applications 5
  • 6. Java NIO  NIO is a collection of Java programming language APIs that offer advanced features for intensive I/O operations  NIO facilitates an implementations that can directly use the most efficient operations of the underlying platform  NIO includes:  Buffers for data of primitive types  Character set encoders and decoders  A pattern-matching facility based on Perl-style regular expressions (in package java.util.regex)  Channels, a new primitive I/O abstraction  A file interface that supports locks and memory mapping  A multiplexed, non-blocking I/O facility for writing scalable servers 6
  • 7. Mule’s “Moves Things Around”  Folder to folder  Queue to queue  Shared memory to shared memory  Using different types of transports  In a flexible way 7
  • 8. XML Pipeline  An XML pipeline is a series of operation that are performed on one or more XML files  Examples include:  validate  transform  prune (remove nodes)  split (break a single XML file into many files)  merge (join two or more files together) 8
  • 9. CRV Example  Flow of XML document through approval processes 9 Submit CRV Deed Matched CRV SSN Stripped CRV Income Tax Audit County Audit County Approval State Audit State Approval
  • 10. Decomposition  Example of XML Operations used on CRV 10 Validate Split Remove SSN Element Store Modify Value Add Element Modify Value Add Element
  • 11. Declarative Approach  Focus on specifying "What" not "How"  Empower business analysis to write machine-readable specifications  Hide the "How" behind services with clear interfaces (SOA) 11
  • 12. Core Mule Concepts  Mule Manager  Mule Model  Universal Message Object (UMO)  Endpoints  External Applications 12
  • 13. Universal Message Object (UMO)  A UMO is a type of Java object that can  receive events "from anywhere"  send events  UMO Components are usually your business objects. They are components that execute business logic on an incoming event  UMO are standard JavaBeans (containers)  There is no Mule-specific code in your components  Mule handles all routing and transformation of events to and from your objects based on the configuration of your component 13
  • 14. Transport  A transport or "provider", is a set of objects that add support to Mule to handle a specific kind of transport or protocol  Examples  the "Email Provider" enables Mule to send and receive messages via the SMTP, POP and IMAP protocols 14
  • 15. Connector  A connector is the object that sends and receives messages on behalf of an endpoint.  Connectors are bundled as part of specific transports or providers.  For example, the FileConnector can read and write file system files. 15
  • 16. Router  A router is the object that do something with messages once they have been received by a connector, or prior to being sent out by the connector 16
  • 17. Filter  A filter optionally filters incoming or outgoing messages that are coming into or going out from a connector.  For example, the File Provider comes with a FilenameWildcardFilter that restricts which files are read by the connector based on file name patterns. For example only files with the .xml extension can be routed.  Filters are used in conjunction with Routers. 17
  • 18. Transformer  A transformer optionally changes incoming or outgoing messages in some way  This is usually done to make the message format useable by a downstream function  Examples:  the ByteArrayToString transformer converts byte arrays into String objects. 18
  • 19. Mule Event Flow  The nine stages of a mule event  first 2 – inbound  middle 4 – component  last 2 – outbound 19 Endpoint (Message Receiver) Endpoint (Message Dispatcher) Inbound Router Outbound Router Inbound Transformer Outbound Transformer Interceptor Service Invocation Interceptor Inbound Component Outbound Optional Step
  • 20. Message Receiver Endpoint  Some event triggers a message flow  A file being written into a folder  A message arriving on a message queue  A record in a database  Data written to a socket 20 Endpoint (Message Dispatcher) Inbound Router Outbound Router Inbound Transformer Outbound Transformer Interceptor Service Invocation Interceptor Endpoint (Message Receiver)
  • 21. Inbound Router  The inbound router is the fist step in a message. Functions typically performed by an inbound router  Filtering  Remove duplicate messages  Matching messages  Aggregation (combining)  Re-sequence data  Forwarding  See also  IdempotentReceiver  CorrolationAggregator  CorrelationResequencer 21 Endpoint (Message Dispatcher) Inbound Router Outbound Router Inbound Transformer Outbound Transformer Interceptor Service Invocation Interceptor Endpoint (Message Receiver)
  • 22. Interceptor  Used to intercept message flow into your service component  Used trigger monitor/events or interrupt the flow of the message  Example: an authorization interceptor could ensure that the current request has the correct credentials to invoke the service. 22 Endpoint (Message Dispatcher) Inbound Router Outbound Router Inbound Transformer Outbound Transformer Service Invocation Interceptor Endpoint (Message Receiver) Interceptor
  • 23. Inbound Transformer  If the inbound data is not in the correct format for the service it must be transformed at this point 23 Endpoint (Message Receiver) Endpoint (Message Dispatcher) Inbound Router Outbound Router Outbound Transformer Interceptor Service Invocation Interceptor Inbound Transformer
  • 24. Service Invocation  The actual service is performed  In mule, this is generally a Java object  Service invocation can also be a "pass through" 24 Endpoint (Message Receiver) Endpoint (Message Dispatcher) Inbound Router Outbound Router Outbound Transformer Interceptor Interceptor Inbound Transformer Service Invocation
  • 25. Outbound Router  Dispatching the data to all the relevant endpoints 25 Endpoint (Message Receiver) Endpoint (Message Dispatcher) Inbound Router Outbound Transformer Interceptor Interceptor Inbound Transformer Service Invocation Outbound Router
  • 26. Built-in Router Classes Inbound Outbound Response Idempotent Receiver Filtering Outbound Router Response Aggregator Selective Consumer Recipient List Aggregator Multicasting Router Resequencer Chaining Router Forwarding Consumer Message Splitter Filtering List Message Splitter Filtering Xml Message Splitter Exception Based Router 26
  • 27. Outbound Transformer  Any transformations that needs to be done on the message after a service has been performed on the message can be executed before it is put into the endpoint  See Also  EnvelopeInterceptor 27 Endpoint (Message Receiver) Endpoint (Message Dispatcher) Inbound Router Interceptor Interceptor Inbound Transformer Service Invocation Outbound Router Outbound Transformer
  • 29. Omitted From Examples for Brevity<?xml version="1.0" encoding="UTF-8"?> <!DOCTYPE mule-configuration PUBLIC "-//MuleSource //DTD mule-configuration XML V1.0//EN" "http://mule.mulesource.org/dtds/mule- configuration.dtd"> 29
  • 30. Outline of Move All Files <mule-configuration> <model> <mule-descriptor> <inbound-router> <endpoint address="file:///c:/mule-class/in"/> </inbound-router> <outbound-router> <router> <endpoint address="file:///c:/mule-class/out"/> </router> </outbound-router> </mule-descriptor> </model> </mule-configuration> 30
  • 31. Move All Files – Procedural Details <mule-configuration id="Mule_File_Move" version=" 1.0"> <connector name="SystemStreamConnector" className="org.mule.providers.stream.SystemStreamConnector"/> <model name="move-all-files"> <mule-descriptor name="move-file" implementation="org.mule.components.simple.BridgeComponent"> <inbound-router> <endpoint address="file:///c:/tmp/in"/> </inbound-router> <outbound-router> <router className="org.mule.routing.outbound.OutboundPassThroughRouter"> <endpoint address="file:///c:/tmp/out"/> </router> </outbound-router> </mule-descriptor> </model> </mule-configuration> 31
  • 32. Only Moving XML Files <inbound-router> <endpoint address="file:///c:/mule-class/in"> <filter pattern="*.xml" className= "org.mule.providers.file.filters.FilenameWildcardFilter"/> </endpoint> </inbound-router> 32 Add the filter line to only move files with the extension "*.xml". If you add a file "foobar.txt to the input folder it will not be moved.
  • 33. Keeping the Name The Same <outbound-router> <router className="org.mule.routing.outbound.OutboundPassThroughRouter"> <endpoint address= "file:///c:/mule-class/out?outputPattern=$[ORIGINALNAME]" /> </router> </outbound-router> 33 Add the outputPattern parameter to keep the output name the same as the input.
  • 34. Happy Path and Exceptions  By default, error free documents follow a central path known as the "happy path"  Documents that have errors may be handled in different ways (rejected, warnings etc.) 34 Start StopStep 1 Step 2 Step 3 Stop Stop Stop
  • 35. Exception Handling  Mule has a special way of handling non-happy path processing. This is called an "Exception Strategy" but is it really just and exception path and there is very little strategy involved.  There are three places you can associate an exception strategy  connector  component  model (set for all components in a model) 35
  • 37. Sample XML <?xml version="1.0" encoding="UTF-8"?> <Data> <Element1>Hello World!</Element1> <Element2>String</Element2> <Element3>String</Element3> <DansInvalidDataElement>This is Dans invalid data element</DansInvalidDataElement> </Data> 37 XML Schema validation will generate an error message when it gets to the fourth invalid data element: Given the following XML Schema file:
  • 38. Validating against an XML Schema<outbound-router> <router className="org.mule.routing.outbound.FilteringXmlMessageSplitter"> <endpoint address="file:///c:/mule-class/out?outputPattern=$[ORIGINALNAME]"/> <properties> <property name="validateSchema" value="true"/> <property name="externalSchemaLocation" value="file:///c:/mule-class/labs/07-validate/my-schema.xsd"/> </properties> </router> </outbound-router> 38 To validate the XML Schema, just add two properties: 1) tell it to validate the document 2) tell it what file to use and where to find it
  • 39. Error Message document : cvc-complex-type.2.4.d: Invalid content was found starting with element 'DansInvalidDataElement'. No child element is expected at this point. 39 This error message is generated on the Mule console when an invalid data element is found. But what should we do with it? How do we redirect it to the appropriate user?