Apache Synapse ESB - Running the Samples
This guide will walk you through the built-in samples shipped with the product,
which will cover most of the basic functional sceanrios and capabilities of Apache Synapse
as an ESB. If you are unable to solve your problem by reading through and
running these samples, feel free to raise your problem on the
mailing lists.
<definitions xmlns="http://ws.apache.org/ns/synapse">
<!-- log all attributes of messages passing through -->
<log level="full"/>
<!-- Send the messageto implicit destination -->
<send/>
</definitions>Objective: Introduction to Synapse. Shows how a message could
be made to pass through Synapse and logged
before it is delivered to its ultimate receiver.
The Stock quote client can operate in the following modes for this
example.
-
Smart Client mode
ant stockquote -Daddurl=http://localhost:9000/soap/SimpleStockQuoteService -Dtrpurl=http://localhost:8280/
-
Using Synapse as a HTTP Proxy
ant stockquote -Daddurl=http://localhost:9000/soap/SimpleStockQuoteService -Dprxurl=http://localhost:8280/
-
Gateway Mode / Dumb Client
See sample # 1
Prerequisites:
Start the Synapse
configuration numbered 0: e.g. synapse -sample 0
Start the Axis2
server and deploy the SimpleStockQuoteService if not already deployed
Execute the Smart Client
By tracing the execution of Synapse with the log output level set to
DEBUG, you will see the client request arriving at Synapse with a
WS-Addressing 'To' set to EPR
http://localhost:9000/soap/SimpleStockQuoteService. The Synapse engine
logs the message at the "full" log level (i.e. all the message headers and
the body) then sends the message to its implicit 'To' address which is
http://localhost:9000/soap/SimpleStockQuoteService. You will see a message
in the Axis2 server console confirming that the message got routed to the
sample server and the sample service hosted at the sample server
generating a stock quote for the requested symbol.
Sat Nov 18 21:01:23 IST 2006 SimpleStockQuoteService :: Generating quote for : IBM
The response message generated by the service is again received by
Synapse, and flows through the same mediation rules, which logs the
response message and then sends it back. This time to the client. On the
client console you should see an output similar to the following based on
the message received by the client.
Standard :: Stock price = $95.26454380258552
Execute the Proxy Client
You will see the exact same behaviour as per the previous example when you
run this scenario. However this time the difference is at the client, as
it sends the message to the WS-Addressing 'To' address
http://localhost:9000/soap/SimpleStockQuoteService, but the transport
specifies Synapse as the HTTP proxy.
<definitions xmlns="http://ws.apache.org/ns/synapse">
<!-- filtering of messages with XPath and regex matches -->
<filter source="get-property('To')" regex=".*/StockQuote.*">
<send>
<endpoint>
<address uri="http://localhost:9000/soap/SimpleStockQuoteService"/>
</endpoint>
</send>
<drop/>
</filter>
<send/>
</definitions> Objective: Introduction to simple content based routing. Shows
how a message could be made to pass through Synapse using the Dumb Client
mode, where Synapse acts as a gateway to accept all messages and then
perform mediation and routing based on message properties or content.
Prerequisites:
Start the Synapse
configuration numbered 1: i.e. synapse -sample 1
Start the Axis2
server and deploy the SimpleStockQuoteService if not already deployed
Execute the Dumb Client as:
ant stockquote -Dtrpurl=http://localhost:8280/soap/StockQuote
This time you will see Synapse receiving a message for which Synapse was
set as the ultimate receiver of the message. Based on the 'To' EPR of
http://localhost:8280/soap/StockQuote, Synapse performs a match to the
path '/StockQuote' and as the request matches the XPath expression of the
filter mediator, the filter mediator's child mediators execute. This sends
the message to a different endpoint as specified by the endpoint
definition. The 'drop' mediator terminates further processing of the
current message in a configuration. During response processing, the filter
condition fails, and thus the implicit 'send' mediator forwards the
response back to the client.
<definitions xmlns="http://ws.apache.org/ns/synapse">
<switch source="//m0:getQuote/m0:request/m0:symbol" xmlns:m0="http://services.samples/xsd">
<case regex="IBM">
<!-- the property mediator sets a local property on the *current* message -->
<property name="symbol" value="Great stock - IBM"/>
</case>
<case regex="MSFT">
<property name="symbol" value="Are you sure? - MSFT"/>
</case>
<default>
<!-- it is possible to assign the result of an XPath expression as well -->
<property name="symbol"
expression="fn:concat('Normal Stock - ', //m0:getQuote/m0:request/m0:symbol)"
xmlns:m0="http://services.samples/xsd"/>
</default>
</switch>
<log level="custom">
<!-- the get-property() XPath extension function allows the lookup of local message properties
as well as properties from the Axis2 or Transport contexts (i.e. transport headers) -->
<property name="symbol" expression="get-property('symbol')"/>
<!-- the get-property() function supports the implicit message headers To/From/Action/FaultTo/ReplyTo -->
<property name="epr" expression="get-property('To')"/>
</log>
<!-- Send the messages where they are destined to (i.e. the 'To' EPR of the message) -->
<send/>
</definitions>Objective: Introduce switch-case mediator and writing and
reading of local properties set on a message instance
Prerequisites:
Start the Synapse
configuration numbered 2: i.e. synapse -sample 2
Start the Axis2
server and deploy the SimpleStockQuoteService if not already done.
Execute the 'ant stockquote ..' request again in the smart client mode,
specifying 'IBM', 'MSFT' and 'SUN' as the stock symbols. When the symbol
IBM is requested, viewing the mediation logs you will see that the case
statements' first case for 'IBM' is executed and a local property named
'symbol' was set to 'Great stock - IBM'. Subsequently this local property
value is looked up by the log mediator and logged using the
'get-property()' XPath extension function.
ant stockquote -Daddurl=http://localhost:9000/soap/SimpleStockQuoteService -Dtrpurl=http://localhost:8280/ -Dsymbol=IBM
INFO LogMediator - symbol = Great stock - IBM, epr = http://localhost:9000/axis2/services/SimpleStockQuoteService
ant stockquote -Daddurl=http://localhost:9000/soap/SimpleStockQuoteService -Dtrpurl=http://localhost:8280/ -Dsymbol=MSFT
INFO LogMediator - symbol = Are you sure? - MSFT, epr = http://localhost:9000/axis2/services/SimpleStockQuoteService
<definitions xmlns="http://ws.apache.org/ns/synapse">
<!-- define a string resource entry to the local registry -->
<localEntry key="version">0.1</localEntry>
<!-- define a reuseable endpoint definition -->
<endpoint name="simple">
<address uri="http://localhost:9000/soap/SimpleStockQuoteService"/>
</endpoint>
<!-- define a reusable sequence -->
<sequence name="stockquote">
<!-- log the message using the custom log level. illustrates custom properties for log -->
<log level="custom">
<property name="Text" value="Sending quote request"/>
<property name="version" expression="get-property('version')"/>
<property name="direction" expression="get-property('direction')"/>
</log>
<!-- send message to real endpoint referenced by key "simple" endpoint definition -->
<send>
<endpoint key="simple"/>
</send>
</sequence>
<sequence name="main">
<in>
<property name="direction" value="incoming"/>
<sequence key="stockquote"/>
</in>
<out>
<send/>
</out>
</sequence>
</definitions>Objective: Illustrates local registry entry definitions,
reusable endpoints and sequences
Prerequisites:
Start the Synapse
configuration numbered 3: i.e. synapse -sample 3
Start the Axis2
server and deploy the SimpleStockQuoteService if not already done
This example uses a sequence named as "main" that specifies the main
mediation rules to be executed. This is equivalent to directly specifying
the mediators of the main sequence within the <definitions> tags.
This is the recommended and also a better approach for non-trivial
configurations. Execute the 'ant stockquote ..' request again, and
following through the mediation logs you will now notice that the sequence
named "main" is executed. Then for the incoming message flow the <in>
mediator executes, and it calls the sequence named "stockquote".
ant stockquote -Daddurl=http://localhost:9000/soap/SimpleStockQuoteService -Dtrpurl=http://localhost:8280/
DEBUG SequenceMediator - Sequence mediator <main> :: mediate()
DEBUG InMediator - In mediator mediate()
DEBUG SequenceMediator - Sequence mediator <stockquote> :: mediate()
As the "stockquote" sequence executes, the log mediator dumps a simple
text/string property, result of an XPath evaluation, that picks up the key
named "version", and a second result of an XPath evaluation that picks up
a local message property set previously by the <property> mediator.
The get-property() XPath extension function is able to read message
properties local to the current message, local or remote registry entries,
Axis2 message context properties as well as transport headers. The local
entry definition for "version" defines a simple text/string registry entry
for that which is visible to all messages that pass through Synapse.
[HttpServerWorker-1] INFO LogMediator - Text = Sending quote request, version = 0.1, direction = incoming
[HttpServerWorker-1] DEBUG SendMediator - Send mediator :: mediate()
[HttpServerWorker-1] DEBUG AddressEndpoint - Sending To: http://localhost:9000/soap/SimpleStockQuoteService
<definitions xmlns="http://ws.apache.org/ns/synapse">
<!-- the default fault handling sequence used by Synapse - named 'fault' -->
<sequence name="fault">
<log level="custom">
<property name="text" value="An unexpected error occured"/>
<property name="message" expression="get-property('ERROR_MESSAGE')"/>
</log>
<drop/>
</sequence>
<sequence name="sunErrorHandler">
<log level="custom">
<property name="text" value="An unexpected error occured for stock SUN"/>
<property name="message" expression="get-property('ERROR_MESSAGE')"/>
</log>
<drop/>
</sequence>
<!-- default message handling sequence used by Synapse - named 'main' -->
<sequence name="main">
<in>
<switch source="//m0:getQuote/m0:request/m0:symbol" xmlns:m0="http://services.samples/xsd">
<case regex="IBM">
<send>
<endpoint><address uri="http://localhost:9000/soap/SimpleStockQuoteService"/></endpoint>
</send>
</case>
<case regex="MSFT">
<send>
<endpoint key="bogus"/>
</send>
</case>
<case regex="SUN">
<sequence key="sunSequence"/>
</case>
</switch>
<drop/>
</in>
<out>
<send/>
</out>
</sequence>
<sequence name="sunSequence" onError="sunErrorHandler">
<send>
<endpoint key="sunPort"/>
</send>
</sequence>
</definitions> Objective: Introduction to error handling with the 'fault'
sequence
Prerequisites:
Start the Synapse
configuration numbered 4: i.e. synapse -sample 4
Start the Axis2
server and deploy the SimpleStockQuoteService if not already done
When the IBM stock quote is requested, the configuration routes it to the
defined in-line endpoint, which routes the message to the
SimpleStockQuoteService on the local Axis2 instance. Hence a valid
response message is shown at the client.
If you lookup a stock quote for 'MSFT', Synapse is instructed to route the
message to the endpoint defined as the 'bogus' endpoint, which does not
exist. Synapse executes the specified error handler sequence closest to
the point where the error was encountered. In this case, the currently
executing sequence is 'main' and it does not specify an 'onError'
attribute. Whenever Synapse cannot find an error handler, it looks for a
sequence named 'fault'. Thus the 'fault' sequence can be seen executing,
and writing the generic error message to the logs.
ant stockquote -Daddurl=http://localhost:9000/soap/SimpleStockQuoteService -Dtrpurl=http://localhost:8280/ -Dsymbol=MSFT
[HttpServerWorker-1] DEBUG SendMediator - Send mediator :: mediate()
[HttpServerWorker-1] ERROR IndirectEndpoint - Reference to non-existent endpoint for key : bogus
[HttpServerWorker-1] DEBUG MediatorFaultHandler - MediatorFaultHandler :: handleFault
[HttpServerWorker-1] DEBUG SequenceMediator - Sequence mediator <fault> :: mediate()
[HttpServerWorker-1] DEBUG LogMediator - Log mediator :: mediate()
[HttpServerWorker-1] INFO LogMediator - text = An unexpected error occured, message = Reference to non-existent endpoint for key : bogus
When the 'SUN' quote is requested, a custom sequence 'sunSequence' is
invoked, and it specifies 'sunErrorHandler' as its error handler. Hence
when the send fails, you could see the proper error handler invocation and
the custom error message printed as follows.
ant stockquote -Daddurl=http://localhost:9000/soap/SimpleStockQuoteService -Dtrpurl=http://localhost:8280/ -Dsymbol=SUN
[HttpServerWorker-1] DEBUG SequenceMediator - Sequence mediator <sunSequence> :: mediate()
[HttpServerWorker-1] DEBUG SequenceMediator - Setting the onError handler for the sequence
[HttpServerWorker-1] DEBUG AbstractListMediator - Implicit Sequence <SequenceMediator> :: mediate()
[HttpServerWorker-1] DEBUG SendMediator - Send mediator :: mediate()
[HttpServerWorker-1] ERROR IndirectEndpoint - Reference to non-existent endpoint for key : sunPort
[HttpServerWorker-1] DEBUG MediatorFaultHandler - MediatorFaultHandler :: handleFault
[HttpServerWorker-1] DEBUG SequenceMediator - Sequence mediator <sunErrorHandler> :: mediate()
[HttpServerWorker-1] DEBUG AbstractListMediator - Implicit Sequence <SequenceMediator> :: mediate()
[HttpServerWorker-1] DEBUG LogMediator - Log mediator :: mediate()
[HttpServerWorker-1] INFO LogMediator - text = An unexpected error occured for stock SUN, message = Reference to non-existent endpoint for key : sunPort
<definitions xmlns="http://ws.apache.org/ns/synapse">
<sequence name="myFaultHandler">
<makefault>
<code value="tns:Receiver" xmlns:tns="http://www.w3.org/2003/05/soap-envelope"/>
<reason expression="get-property('ERROR_MESSAGE')"/>
</makefault>
<property name="RESPONSE" value="true"/>
<header name="To" expression="get-property('ReplyTo')"/>
<send/>
</sequence>
<sequence name="main" onError="myFaultHandler">
<in>
<switch source="//m0:getQuote/m0:request/m0:symbol"
xmlns:m0="http://services.samples/xsd">
<case regex="MSFT">
<send>
<endpoint><address uri="http://bogus:9000/soap/NonExistentStockQuoteService"/></endpoint>
</send>
</case>
<case regex="SUN">
<send>
<endpoint><address uri="http://localhost:9009/soap/NonExistentStockQuoteService"/></endpoint>
</send>
</case>
</switch>
<drop/>
</in>
<out>
<send/>
</out>
</sequence>
</definitions>Objective: Makefault mediator and sending back error responses
Prerequisites:
Start the Synapse
configuration numbered 5: i.e. synapse -sample 5
Start the Axis2
server and deploy the SimpleStockQuoteService if not already done
When the MSFT stock quote is requested, an unknown host exception would be
generated. A connection refused exception would be generated for the SUN
stock request. This error message is captured and returned to the original
client as a SOAP fault in this example.
ant stockquote -Daddurl=http://localhost:9000/soap/SimpleStockQuoteService -Dtrpurl=http://localhost:8280/ -Dsymbol=MSFT
returns,
<soapenv:Fault xmlns:soapenv="http://schemas.xmlsoap.org/soap/envelope/"><faultcode>soapenv:Client</faultcode>
<faultstring>java.net.UnknownHostException: bogus</faultstring><detail /></soapenv:Fault>
And
ant stockquote -Daddurl=http://localhost:9000/soap/SimpleStockQuoteService -Dtrpurl=http://localhost:8280/ -Dsymbol=SUN
returns,
<soapenv:Fault xmlns:soapenv="http://schemas.xmlsoap.org/soap/envelope/"><faultcode>soapenv:Client</faultcode>
<faultstring>java.net.ConnectException: Connection refused</faultstring><detail /></soapenv:Fault><definitions xmlns="http://ws.apache.org/ns/synapse">
<in>
<header name="To" value="http://localhost:9000/soap/SimpleStockQuoteService"/>
</in>
<send/>
</definitions>Objective: Introduction to header, in (out) mediators
Prerequisites:
Start the Synapse
configuration numbered 6: i.e. synapse -sample 6
Start the Axis2
server and deploy the SimpleStockQuoteService if not already done
In this example we use the stockquote client in the dumb client mode,
setting the 'To' EPR of the message to Synapse. Then the 'in' mediator
processes the incoming messages, and manipulates the 'To' header to refer
to the stock quote service on the sample Axis2 server. Thus it is now
possible to request for a stock quote as follows.
ant stockquote -Dtrpurl=http://localhost:8280/
<definitions xmlns="http://ws.apache.org/ns/synapse">
<localEntry key="validate_schema">
<xs:schema xmlns:xs="http://www.w3.org/2001/XMLSchema"
xmlns="http://www.apache-synapse.org/test" elementFormDefault="qualified"
attributeFormDefault="unqualified"
targetNamespace="http://services.samples/xsd">
<xs:element name="getQuote">
<xs:complexType>
<xs:sequence>
<xs:element name="request">
<xs:complexType>
<xs:sequence>
<xs:element name="stocksymbol" type="xs:string"/>
</xs:sequence>
</xs:complexType>
</xs:element>
</xs:sequence>
</xs:complexType>
</xs:element>
</xs:schema>
</localEntry>
<in>
<validate>
<schema key="validate_schema"/>
<on-fail>
<!-- if the request does not validate againt schema throw a fault -->
<makefault>
<code value="tns:Receiver"
xmlns:tns="http://www.w3.org/2003/05/soap-envelope"/>
<reason value="Invalid custom quote request"/>
</makefault>
<property name="RESPONSE" value="true"/>
<header name="To" expression="get-property('ReplyTo')"/>
</on-fail>
</validate>
</in>
<send/>
</definitions> Objective: Introduction to local (static) registry entries and
the validate mediator
Prerequisites:
Start the Synapse
configuration numbered 7: i.e. synapse -sample 7
Start the Axis2
server and deploy the SimpleStockQuoteService if not already done
This example shows how a static XML fragment could be made available to
the Synapse local registry. Resources defined in the local registry are
static (i.e. never changes over the lifetime of the configuration) and may
be specified as a source URL, in-line text or in-line xml. In this example
the schema is made available under the key 'validate_schema'.
The validate mediator by default operates on the first child element of
the SOAP body. You may specify an XPath expression using the 'source'
attribute to override this behaviour. The validate mediator now uses the
'validate_schema' resource to validate the incoming message, and if the
message validation fails it invokes the 'on-fail' sequence of mediators.
If you send a stockquote request using 'ant stockquote ...' you will get a
fault back with the message 'Invalid custom quote request' as the schema
validation failed. This is because the schema used in the example expects
a slightly different message than what is created by the stock quote
client. (i.e. expects a 'stocksymbol' element instead of 'symbol' to
specify the stock symbol)
ant stockquote -Daddurl=http://localhost:9000/soap/SimpleStockQuoteService -Dtrpurl=http://localhost:8280/
<definitions xmlns="http://ws.apache.org/ns/synapse">
<!-- the SimpleURLRegistry allows access to a URL based registry (e.g. file:/// or http://) -->
<registry provider="org.apache.synapse.registry.url.SimpleURLRegistry">
<!-- the root property of the simple URL registry helps resolve a resource URL as root + key -->
<parameter name="root">file:./repository/conf/sample/resources/</parameter>
<!-- all resources loaded from the URL registry would be cached for this number of milli seconds -->
<parameter name="cachableDuration">15000</parameter>
</registry>
<!-- define the request processing XSLT resource as a static URL source -->
<localEntry key="xslt-key-req" src="file:repository/conf/sample/resources/transform/transform.xslt"/>
<in>
<!-- transform the custom quote request into a standard quote requst expected by the service -->
<xslt key="xslt-key-req"/>
</in>
<out>
<!-- transform the standard response back into the custom format the client expects -->
<!-- the key is looked up in the remote registry and loaded as a 'dynamic' registry resource -->
<xslt key="transform/transform_back.xslt"/>
</out>
<send/>
</definitions>Objective: Introduction to static and dynamic registry
resources and the XSLT mediator
Prerequisites:
Start the Synapse
configuration numbered 8: i.e. synapse -sample 8
Start the Axis2
server and deploy the SimpleStockQuoteService if not already done
This example uses the XSLT mediator to perform transformations, and the
xslt transformations are specified as registry resources. The first
resource 'xslt-key-req' is specified as a 'local' registry entry. Local
entries do not place the resource on the registry, but simply make it
available to the local configuration. If a local entry is defined with a
key that already exists in the remote registry, the local entry will get
higher preference and override the remote resource.
In this example you will notice the new 'registry' definition. Synapse
comes with a simple URL based registry implementation SimpleURLRegistry.
During initialization of the registry, the SimpleURLRegistry expects to
find a property named 'root', which specifies a prefix for the registry
keys used later. When the SimpleURLRegistry is used, this root is prefixed
to the entry keys to form the complete URL for the resource being looked
up. The registry caches a resource once requested, and caches it
internally for a specified duration. Once this period expires, it will
reload the meta information about the resource and reload its cached copy
if necessary, the next time the resource is requested.
Hence the second XSLT resource key 'transform/transform_back.xslt'
concatenated with the 'root' of the SimpleURLRegistry
'file:repository/conf/sample/resources/' forms the complete URL of the
resource as
'file:repository/conf/sample/resources/transform/transform_back.xslt' and
caches its value for a period of 15000 ms.
Execute the custom quote client as 'ant stockquote -Dmode=customquote ...'
and analyze the the Synapse debug log output
ant stockquote -Daddurl=http://localhost:9000/soap/SimpleStockQuoteService -Dtrpurl=http://localhost:8280/ -Dmode=customquote
The incoming message is now transformed into a standard stock quote
request as expected by the SimpleStockQuoteService deployed on the local
Axis2 instance, by the XSLT mediator. The XSLT mediator uses Xalan-J to
perform the transformations. It is possible to configure the underlying
transformation engine using properties where necessary. The response from
the SimpleStockQuoteService is converted back into the custom format as
expected by the client during the out message processing.
During the response processing you could see the SimpleURLRegistry
fetching the resource as shown by the log message below
[HttpClientWorker-1] DEBUG SimpleURLRegistry ==> Repository fetch of resource with key : transform/transform_back.xslt
If you run the client again immediately (i.e within 15 seconds of the
first request) you will not see the resource being reloaded by the
registry as the cached value would be still valid.
However if you leave the system idle for 15 seconds or more and then retry
the same request, you will now notice that the registry noticed the cached
resource has expired and will check the meta information about the
resource to check if the resource itself has changed and will require a
fresh fetch from the source URL. If the meta data / version number
indicates that a reload of the cached resource is not necessary (i.e.
unless the resource itself actually changed) the updated meta information
is used and the cache lease extended as appropriate.
[HttpClientWorker-1] DEBUG AbstractRegistry - Cached object has expired for key : transform/transform_back.xslt
[HttpClientWorker-1] DEBUG SimpleURLRegistry - Perform RegistryEntry lookup for key : transform/transform_back.xslt
[HttpClientWorker-1] DEBUG AbstractRegistry - Expired version number is same as current version in registry
[HttpClientWorker-1] DEBUG AbstractRegistry - Renew cache lease for another 15s
Now edit the
repository/conf/sample/resources/transform/transform_back.xslt file and
add a blank line at the end. Now when you run the client again, and if the
cache is expired, the resource would be re-fetched from its URL by the
registry and this can be seen by the following debug log messages
[HttpClientWorker-1] DEBUG AbstractRegistry - Cached object has expired for key : transform/transform_back.xslt
[HttpClientWorker-1] DEBUG SimpleURLRegistry - Perform RegistryEntry lookup for key : transform/transform_back.xslt
[HttpClientWorker-1] INFO SimpleURLRegistry - ==> Repository fetch of resource with key : transform/transform_back.xslt
Thus the SimpleURLRegistry allows resource to be cached, and updates
detected so that the changes could be reloaded without restarting the
Synapse instance.
<definitions xmlns="http://ws.apache.org/ns/synapse">
<registry provider="org.apache.synapse.registry.url.SimpleURLRegistry">
<parameter name="root">file:./repository/conf/sample/resources/</parameter>
<parameter name="cachableDuration">15000</parameter>
</registry>
<sequence key="sequence/dynamic_seq_1.xml"/>
</definitions> Objective: Introduction to dynamic sequences with a registry
Prerequisites:
Start the Synapse
configuration numbered 9: i.e. synapse -sample 9
Start the Axis2
server and deploy the SimpleStockQuoteService if not already done
This example introduces the dynamic behaviour of Synapse through the use
of a registry. Synapse supports dynamic definitions for sequences and
endpoints, and as seen before, for resources. In this example we define a
Synapse configuration which references a sequence definition specified as
a registry key. The registry key resolves to the actual content of the
sequence which would be loaded dynamically by Synapse at runtime, and
cached appropriately as per its definition in the registry. Once the cache
expires, Synapse would re-check the meta information for the definition and
re-load the sequence definition if necessary and re-cache it again.
Once Synapse is started, execute the stock quote client as 'ant
stockquote..'. You will notice that that Synapse fetches the definition of
the sequence from the registry and executes its rules as follows:
ant stockquote -Daddurl=http://localhost:9000/soap/SimpleStockQuoteService -Dtrpurl=http://localhost:8280/
[HttpServerWorker-1] DEBUG SimpleURLRegistry - ==> Repository fetch of resource with key : sequence/dynamic_seq_1.xml
...
[HttpServerWorker-1] DEBUG SequenceMediator - Sequence mediator <dynamic_sequence> :: mediate()
...
[HttpServerWorker-1] INFO LogMediator - message = *** Test Message 1 ***
Now if you execute the client immediately (i.e. within 15 seconds of the
last execution) you will notice that the sequence was not reloaded. If you
edit the sequence definition in
repository/conf/sample/resources/sequence/dynamic_seq_1.xml (i.e. edit the
log message to read as "*** Test Message 2 ***") and execute the client
again, you will notice that the new message is not yet visible (i.e. if
you execute this within 15 seconds of loading the resource for the first
time) However, after 15 seconds elapsed since the original caching of the
sequence, you will notice that the new sequence is loaded and executed by
Synapse from the following log messages.
[HttpServerWorker-1] DEBUG SimpleURLRegistry - ==> Repository fetch of resource with key : sequence/dynamic_seq_1.xml
...
[HttpServerWorker-1] DEBUG SequenceMediator - Sequence mediator <dynamic_sequence> :: mediate()
...
[HttpServerWorker-1] INFO LogMediator - message = *** Test Message 2 ***
The cache timeout could be tuned appropriately by configuring the URL
registry to suit the environment and the needs.
<definitions xmlns="http://ws.apache.org/ns/synapse">
<registry provider="org.apache.synapse.registry.url.SimpleURLRegistry">
<parameter name="root">file:repository/conf/sample/resources/</parameter>
<parameter name="cachableDuration">15000</parameter>
</registry>
<in>
<send>
<endpoint key="endpoint/dynamic_endpt_1.xml"/>
</send>
</in>
<out>
<send/>
</out>
</definitions> Objective: Introduction to dynamic endpoints with the Registry
Prerequisites:
Start the Synapse
configuration numbered 10: i.e. synapse -sample 10
Start the Axis2
server and deploy the SimpleStockQuoteService if not already done
Start a second Axis2 server on HTTP port 9001 and HTTPS port 9003 as
follows:
./axis2server.sh -http 9001 -https 9003
This example introduces dynamic endpoints, where the definition of an
endpoint is stored in the registry. To follow this example execute the
stock quote client as 'ant stockquote..' and see that the message is
routed to the SimpleStockQuoteService on the default Axis2 instance on
HTTP port 9000. Repeat the above example immediately again, and notice
that the endpoint is cached and reused by Synapse - similarly to example #
8.
ant stockquote -Dtrpurl=http://localhost:8280/
Now edit the repository/conf/sample/resources/endpoint/dynamic_endpt_1.xml
definition and update the address to
"http://localhost:9001/soap/SimpleStockQuoteService". After the cached value
expires, the Registry loads the new definition of the endpoint, and then
the messages can be seen being routed to the second sample Axis2 server on
HTTP port 9001.
<definitions xmlns="http://ws.apache.org/ns/synapse">
<registry provider="org.apache.synapse.registry.url.SimpleURLRegistry">
<parameter name="root">file:./repository/conf/sample/resources/</parameter>
<parameter name="cachableDuration">15000</parameter>
</registry>
</definitions> Objective: A full registry based configuration
Prerequisites:
Start the Synapse
configuration numbered 11: i.e. synapse -sample 11
Start the Axis2
server and deploy the SimpleStockQuoteService if not already done
This example shows a full registry based Synapse configuration. Thus it is
possible to start a remote configuration from multiple instances of
Synapse in a clustered environment easily. The Synapse configuration held
on a node hosting Synapse simply points to the registry and looks up the
actual configuration by requesting the key 'synapse.xml'.
(Note: Full registry based configuration is not dynamic atleast for the
moment. i.e. it is not reloading itself)
ant stockquote -Daddurl=http://localhost:9000/soap/SimpleStockQuoteService -Dtrpurl=http://localhost:8280/
[HttpServerWorker-1] INFO LogMediator - message = This is a dynamic Synapse configuration
The actual synapse.xml loaded is:
<!-- a registry based Synapse configuration -->
<definitions xmlns="http://ws.apache.org/ns/synapse">
<log level="custom">
<property name="message" value="This is a dynamic Synapse configuration $$$"/>
</log>
<send/>
</definitions>Objective: Demonstrate one-way messaging / fireAndForget
through Synapse
Prerequisites:
Start the Axis2 server
and deploy the SimpleStockQuoteService (Refer steps above)
Start
the Synapse configuration numbered 1: i.e. synapse -sample 1
This example invokes the one-way 'placeOrder' operation on the
SimpleStockQuoteService using the custom client which uses the Axis2
ServiceClient.fireAndForget() API. To test this, use 'ant
-Dmode=placeorder...' and you will notice the one-way message flowing
through Synapse into the sample Axis2 server instance, which reports the
acceptance of the order as follows:
ant stockquote -Daddurl=http://localhost:9000/soap/SimpleStockQuoteService -Dtrpurl=http://localhost:8280/ -Dmode=placeorder
SimpleStockQuoteService :: Accepted order for : 7482 stocks of IBM at $ 169.27205579038733
If you send your client request through TCPmon, you will notice that the
SimpleStockQuoteService replies to Synapse with a HTTP 202 reply, and that
Synapse in turns replies to the client with a HTTP 202 acknowledgment
Objective: Demonstrate dual channel messaging
through Synapse
Prerequisites:
Start the Axis2 server
and deploy the SimpleStockQuoteService (Refer steps above)
Start
the Synapse configuration numbered 0: i.e. synapse -sample 0
This example invokes the same 'getQuote' operation on the
SimpleStockQuoteService using the custom client which uses the Axis2
ServiceClient API with useSeparateListener set to true so that the response is
coming through a different channel than the one which is used to send the request
to a callback defined in the client.
To test this, use 'ant
-Dmode=dualquote...' and you will notice the dual channel invocation
through Synapse into the sample Axis2 server instance, which reports the response
back to the client over a different channel:
ant stockquote -Daddurl=http://localhost:9000/soap/SimpleStockQuoteService -Dtrpurl=http://localhost:8280/ -Dmode=dualquote
Response received to the callback
Standard dual channel :: Stock price = $57.16686934968289
If you send your client request through TCPmon, you will notice that
Synapse replies to the client with a HTTP 202 acknowledgment when you send the request and
the communication between Synapse and the server happens on a single channel and then you
get the response back from Synapse to the clients callback in a different channel (which
cannot be observed through TCPmon)
Also you could see the wsa:Reply-To header being something like
http://localhost:8200/axis2/soap/anonService2 which implies that the reply
is being on a different channel listening on the port 8200. Please note that it is
required to engage addressing when using the dual channel invocation because it
requires the wsa:Reply-To header.
<definitions xmlns="http://ws.apache.org/ns/synapse">
<!-- filtering of messages with XPath and regex matches -->
<filter source="get-property('To')" regex=".*/StockQuote.*">
<send>
<endpoint>
<address uri="http://localhost:9000/soap/SimpleStockQuoteService" format="soap11"/>
</endpoint>
</send>
<drop/>
</filter>
<send/>
</definitions> Objective: POX to SOAP conversion
Prerequisites:
Start the Synapse
configuration numbered 50: i.e. synapse -sample 50
Start the Axis2 server and deploy the SimpleStockQuoteService if not
already done
Execute the 'ant stockquote' specifying that the request should be a REST
request as follows:
ant stockquote -Dtrpurl=http://localhost:8280/soap/StockQuote -Drest=true
This example shows a HTTP REST request (as shown below) being transformed
into a SOAP request and forwarded to the stock quote service.
POST /soap/StockQuote HTTP/1.1
Content-Type: application/xml; charset=UTF-8;action="urn:getQuote";
SOAPAction: urn:getQuote
User-Agent: Axis2
Host: 127.0.0.1
Transfer-Encoding: chunked
75
<m0:getQuote xmlns:m0="http://services.samples/xsd">
<m0:request>
<m0:symbol>IBM</m0:symbol>
</m0:request>
</m0:getQuote>0<definitions xmlns="http://ws.apache.org/ns/synapse">
<in>
<filter source="get-property('Action')" regex="urn:uploadFileUsingMTOM">
<property name="example" value="mtom"/>
<send>
<endpoint>
<address uri="http://localhost:9000/soap/MTOMSwASampleService" optimize="mtom"/>
</endpoint>
</send>
</filter>
<filter source="get-property('Action')" regex="urn:uploadFileUsingSwA">
<property name="example" value="swa"/>
<send>
<endpoint>
<address uri="http://localhost:9000/soap/MTOMSwASampleService" optimize="swa"/>
</endpoint>
</send>
</filter>
</in>
<out>
<filter source="get-property('example')" regex="mtom">
<property name="enableMTOM" value="true" scope="axis2"/>
</filter>
<filter source="get-property('example')" regex="swa">
<property name="enableSwA" value="true" scope="axis2"/>
</filter>
<send/>
</out>
</definitions>Objective: MTOM and SwA optimizations and request/response
correlation
Prerequisites:
Start the Synapse
configuration numbered 51: i.e. synapse -sample 51
Start the Axis2
server and deploy the MTOMSwASampleService if not already done
Execute the 'ant optimizeclient' specifying MTOM optimization as follows:
ant optimizeclient -Dopt_mode=mtom
The configuration now sets a local message context property, and forwards
the message to 'http://localhost:9000/soap/MTOMSwASampleService'
optimizing binary content as MTOM. By sending this message through TCPMon
you would be able to see the actual message sent over the HTTP transport
if required. Thus during response processing, by checking the local
message property Synapse could identify the past information about the
current message context, and uses this knowledge to transform the response
back to the client in the same format as the original request.
When the client executes successfully, it will upload a file containing
the ASF logo and receive its response back again and saves it into a
temporary file.
[java] Sending file : ./../../repository/conf/sample/resources/mtom/asf-logo.gif as MTOM
[java] Saved response to file : ./../../work/temp/sampleClient/mtom-4417.gif
Next try SwA as:
ant optimizeclient -Dopt_mode=swa
[java] Sending file : ./../../repository/conf/sample/resources/mtom/asf-logo.gif as SwA
[java] Saved response to file : ./../../work/temp/sampleClient/swa-30391.gif
By using TCPMon and sending the message through it, one can inspect that
the requests and responses sent are indeed MTOM optimized or sent as HTTP
attachments as follows:
POST http://localhost:9000/soap/MTOMSwASampleService HTTP/1.1
Host: 127.0.0.1
SOAPAction: urn:uploadFileUsingMTOM
Content-Type: multipart/related; boundary=MIMEBoundaryurn_uuid_B94996494E1DD5F9B51177413845353; type="application/xop+xml";
start="<0.urn:uuid:B94996494E1DD5F9B51177413845354@apache.org>"; start-info="text/xml"; charset=UTF-8
Transfer-Encoding: chunked
Connection: Keep-Alive
User-Agent: Synapse-HttpComponents-NIO
--MIMEBoundaryurn_uuid_B94996494E1DD5F9B51177413845353241
Content-Type: application/xop+xml; charset=UTF-8; type="text/xml"
Content-Transfer-Encoding: binary
Content-ID:
<0.urn:uuid:B94996494E1DD5F9B51177413845354@apache.org>221b1
<?xml version='1.0' encoding='UTF-8'?>
<soapenv:Envelope xmlns:soapenv="http://schemas.xmlsoap.org/soap/envelope/">
<soapenv:Body>
<m0:uploadFileUsingMTOM xmlns:m0="http://www.apache-synapse.org/test">
<m0:request>
<m0:image>
<xop:Include href="cid:1.urn:uuid:78F94BC50B68D76FB41177413845003@apache.org" xmlns:xop="http://www.w3.org/2004/08/xop/include" />
</m0:image>
</m0:request>
</m0:uploadFileUsingMTOM>
</soapenv:Body>
</soapenv:Envelope>
--MIMEBoundaryurn_uuid_B94996494E1DD5F9B51177413845353217
Content-Type: image/gif
Content-Transfer-Encoding: binary
Content-ID:
<1.urn:uuid:78F94BC50B68D76FB41177413845003@apache.org>22800GIF89a... << binary content >>POST http://localhost:9000/soap/MTOMSwASampleService HTTP/1.1
Host: 127.0.0.1
SOAPAction: urn:uploadFileUsingSwA
Content-Type: multipart/related; boundary=MIMEBoundaryurn_uuid_B94996494E1DD5F9B51177414170491; type="text/xml";
start="<0.urn:uuid:B94996494E1DD5F9B51177414170492@apache.org>"; charset=UTF-8
Transfer-Encoding: chunked
Connection: Keep-Alive
User-Agent: Synapse-HttpComponents-NIO
--MIMEBoundaryurn_uuid_B94996494E1DD5F9B51177414170491225
Content-Type: text/xml; charset=UTF-8
Content-Transfer-Encoding: 8bit
Content-ID:
<0.urn:uuid:B94996494E1DD5F9B51177414170492@apache.org>22159
<?xml version='1.0' encoding='UTF-8'?>
<soapenv:Envelope xmlns:soapenv="http://schemas.xmlsoap.org/soap/envelope/">
<soapenv:Body>
<m0:uploadFileUsingSwA xmlns:m0="http://www.apache-synapse.org/test">
<m0:request>
<m0:imageId>urn:uuid:15FD2DA2584A32BF7C1177414169826</m0:imageId>
</m0:request>
</m0:uploadFileUsingSwA>
</soapenv:Body>
</soapenv:Envelope>22--34MIMEBoundaryurn_uuid_B94996494E1DD5F9B511774141704912
17
Content-Type: image/gif
Content-Transfer-Encoding: binary
Content-ID:
<urn:uuid:15FD2DA2584A32BF7C1177414169826>22800GIF89a... << binary content >><definitions xmlns="http://ws.apache.org/ns/synapse">
<sequence name="main" onError="errorHandler">
<in>
<send>
<endpoint>
<loadbalance>
<endpoint>
<address uri="http://localhost:9001/soap/LBService1">
<enableAddressing/>
<suspendDurationOnFailure>60</suspendDurationOnFailure>
</address>
</endpoint>
<endpoint>
<address uri="http://localhost:9002/soap/LBService1">
<enableAddressing/>
<suspendDurationOnFailure>60</suspendDurationOnFailure>
</address>
</endpoint>
<endpoint>
<address uri="http://localhost:9003/soap/LBService1">
<enableAddressing/>
<suspendDurationOnFailure>60</suspendDurationOnFailure>
</address>
</endpoint>
</loadbalance>
</endpoint>
</send>
<drop/>
</in>
<out>
<!-- Send the messages where they have been sent (i.e. implicit To EPR) -->
<send/>
</out>
</sequence>
<sequence name="errorHandler">
<makefault>
<code value="tns:Receiver" xmlns:tns="http://www.w3.org/2003/05/soap-envelope"/>
<reason value="COULDN'T SEND THE MESSAGE TO THE SERVER."/>
</makefault>
<header name="To" action="remove"/>
<property name="RESPONSE" value="true"/>
<send/>
</sequence>
</definitions>Objective: Demonstrate the simple load balancing among a set of
endpoints
Prerequisites:
Start Synapse with sample configuration 52. (i.e. synapse -sample 52)
Deploy the LoadbalanceFailoverService by switching to <Synapse
installation directory>/samples/axis2Server/src/LoadbalanceFailoverService
directory and running ant.
Start three instances of sample Axis2 server on HTTP ports 9001, 9002 and
9003 and give some unique names to each server.
Example commands to run sample Axis2 servers from the <Synapse
installation directory>/samples/axis2Server directory in Linux are
listed below:
./axis2server.sh -http 9001 -https 9005 -name MyServer1
./axis2server.sh -http 9002 -https 9006 -name MyServer2
./axis2server.sh -http 9003 -https 9007 -name MyServer3
Now we are done with setting up the environment for load balance sample.
Start the load balance and failover client using the following command:
ant loadbalancefailover -Di=100
This client sends 100 requests to the LoadbalanceFailoverService through
Synapse. Synapse will distribute the load among the three endpoints
mentioned in the configuration in round-robin manner.
LoadbalanceFailoverService appends the name of the server to the response,
so that client can determine which server has processed the message. If
you examine the console output of the client, you can see that requests
are processed by three servers as follows:
[java] Request: 1 ==> Response from server: MyServer1
[java] Request: 2 ==> Response from server: MyServer2
[java] Request: 3 ==> Response from server: MyServer3
[java] Request: 4 ==> Response from server: MyServer1
[java] Request: 5 ==> Response from server: MyServer2
[java] Request: 6 ==> Response from server: MyServer3
[java] Request: 7 ==> Response from server: MyServer1
...
Now run the client without the -Di=100 parameter to send infinite
requests. While running the client shutdown the server named MyServer1.
You can observe that requests are only distributed among MyServer2 and
MyServer3 after shutting down MyServer1. Console output before and after
shutting down MyServer1 is listed below (MyServer1 was shutdown after
request 63):
...
[java] Request: 61 ==> Response from server: MyServer1
[java] Request: 62 ==> Response from server: MyServer2
[java] Request: 63 ==> Response from server: MyServer3
[java] Request: 64 ==> Response from server: MyServer2
[java] Request: 65 ==> Response from server: MyServer3
[java] Request: 66 ==> Response from server: MyServer2
[java] Request: 67 ==> Response from server: MyServer3
...
Now restart MyServer1. You can observe that requests will be again sent to
all three servers roughly after 60 seconds. This is because we have
specified <suspendDurationOnFailure> as 60 seconds in the
configuration. Therefore, load balance endpoint will suspend any failed
child endpoint only for 60 seconds after detecting the failure.
<definitions xmlns="http://ws.apache.org/ns/synapse">
<sequence name="main" onError="errorHandler">
<in>
<send>
<endpoint>
<failover>
<endpoint>
<address uri="http://localhost:9001/soap/LBService1">
<enableAddressing/>
<suspendDurationOnFailure>60</suspendDurationOnFailure>
</address>
</endpoint>
<endpoint>
<address uri="http://localhost:9002/soap/LBService1">
<enableAddressing/>
<suspendDurationOnFailure>60</suspendDurationOnFailure>
</address>
</endpoint>
<endpoint>
<address uri="http://localhost:9003/soap/LBService1">
<enableAddressing/>
<suspendDurationOnFailure>60</suspendDurationOnFailure>
</address>
</endpoint>
</failover>
</endpoint>
</send>
<drop/>
</in>
<out>
<!-- Send the messages where they have been sent (i.e. implicit To EPR) -->
<send/>
</out>
</sequence>
<sequence name="errorHandler">
<makefault>
<code value="tns:Receiver" xmlns:tns="http://www.w3.org/2003/05/soap-envelope"/>
<reason value="COULDN'T SEND THE MESSAGE TO THE SERVER."/>
</makefault>
<header name="To" action="remove"/>
<property name="RESPONSE" value="true"/>
<send/>
</sequence>
</definitions>Objective: Demonstrate the failover sending
Prerequisites:
Start Synapse with sample configuration 53 (i.e. synapse -sample 53)
Deploy the LoadbalanceFailoverService and start three instances of sample
Axis2 server as mentioned in sample 52.
Above configuration sends messages with the failover behavior. Initially
the server at port 9001 is treated as primary and other two are treated as
backups. Messages are always directed only to the primary server. If the
primary server has failed, next listed server is selected as the primary.
Thus, messages are sent successfully as long as there is at least one
active server. To test this, run the loadbalancefailover client to send
infinite requests as follows:
ant loadbalancefailover
You can see that all requests are processed by MyServer1. Now shutdown
MyServer1 and inspect the console output of the client. You will observe
that all subsequent requests are processed by MyServer2.
The console output with MyServer1 shutdown after request 127 is listed
below:
...
[java] Request: 125 ==> Response from server: MyServer1
[java] Request: 126 ==> Response from server: MyServer1
[java] Request: 127 ==> Response from server: MyServer1
[java] Request: 128 ==> Response from server: MyServer2
[java] Request: 129 ==> Response from server: MyServer2
[java] Request: 130 ==> Response from server: MyServer2
...
You can keep on shutting down servers like this. Client will get a
response till you shutdown all listed servers. Once all servers are
shutdown, the error sequence is activated and a fault message is sent to
the client as follows.
[java] COULDN'T SEND THE MESSAGE TO THE SERVER.
Once a server is detected as failed, it will be added to the active
servers list again after 60 seconds (specified in <suspendDurationOnFailure>
in the configuration). Therefore, if you have restarted any of the stopped
servers and have shutdown all other servers, messages will be directed to
the newly started server.
<definitions xmlns="http://ws.apache.org/ns/synapse">
<sequence name="main" onError="errorHandler">
<in>
<send>
<endpoint>
<!-- specify the session as the simple client session provided by Synapse for
testing purpose -->
<session type="simpleClientSession"/>
<loadbalance>
<endpoint>
<address uri="http://localhost:9001/soap/LBService1">
<enableAddressing/>
</address>
</endpoint>
<endpoint>
<address uri="http://localhost:9002/soap/LBService1">
<enableAddressing/>
</address>
</endpoint>
<endpoint>
<address uri="http://localhost:9003/soap/LBService1">
<enableAddressing/>
</address>
</endpoint>
</loadbalance>
</endpoint>
</send>
<drop/>
</in>
<out>
<!-- Send the messages where they have been sent (i.e. implicit To EPR) -->
<send/>
</out>
</sequence>
<sequence name="errorHandler">
<makefault>
<code value="tns:Receiver" xmlns:tns="http://www.w3.org/2003/05/soap-envelope"/>
<reason value="COULDN'T SEND THE MESSAGE TO THE SERVER."/>
</makefault>
<header name="To" action="remove"/>
<property name="RESPONSE" value="true"/>
<send/>
</sequence>
</definitions>Objective: Demonstrate the loadbalancing with session affinity
using client initiated sessions
Prerequisites:
Start Synapse with sample configuration 54 (i.e. synapse -sample 54).
Deploy the LoadbalanceFailoverService and start three instances of the
sample Axis2 server as in sample 52.
Above configuration is same as the load balancing configuration in sample
52, except that the session type is specified as "simpleClientSession".
This is a client initiated session, which means that the client generates
the session identifier and sends it with each request. In this sample
session type, client adds a SOAP header named ClientID containing the
identifier of the client. Synapse binds this ID with a server on the first
request and sends all successive requests containing that ID to the same
server. Now switch to samples/axis2Client directory and run the client
using the following command to check this in action.
ant loadbalancefailover -Dmode=session
In the session mode, client continuously sends requests with three different
client (session) IDs. One ID is selected among these three IDs for each
request randomly. Then client prints the session ID with the responded
server for each request. Client output for the first 10 requests are shown
below.
[java] Request: 1 Session number: 1 Response from server: MyServer3
[java] Request: 2 Session number: 2 Response from server: MyServer2
[java] Request: 3 Session number: 0 Response from server: MyServer1
[java] Request: 4 Session number: 2 Response from server: MyServer2
[java] Request: 5 Session number: 1 Response from server: MyServer3
[java] Request: 6 Session number: 2 Response from server: MyServer2
[java] Request: 7 Session number: 2 Response from server: MyServer2
[java] Request: 8 Session number: 1 Response from server: MyServer3
[java] Request: 9 Session number: 0 Response from server: MyServer1
[java] Request: 10 Session number: 0 Response from server: MyServer1
...
You can see that session number 0 is always directed to the server named
MyServer1. That means session number 0 is bound to MyServer1. Similarly
session 1 and 2 are bound to MyServer3 and MyServer2 respectively.
<definitions xmlns="http://ws.apache.org/ns/synapse">
<sequence name="main" onError="errorHandler">
<in>
<send>
<endpoint>
<!-- specify the session as the simple client session provided by Synapse for
testing purpose -->
<session type="simpleClientSession"/>
<loadbalance>
<endpoint>
<failover>
<endpoint>
<address uri="http://localhost:9001/soap/LBService1">
<enableAddressing/>
</address>
</endpoint>
<endpoint>
<address uri="http://localhost:9002/soap/LBService1">
<enableAddressing/>
</address>
</endpoint>
</failover>
</endpoint>
<endpoint>
<failover>
<endpoint>
<address uri="http://localhost:9003/soap/LBService1">
<enableAddressing/>
</address>
</endpoint>
<endpoint>
<address uri="http://localhost:9004/soap/LBService1">
<enableAddressing/>
</address>
</endpoint>
</failover>
</endpoint>
</loadbalance>
</endpoint>
</send>
<drop/>
</in>
<out>
<!-- Send the messages where they have been sent (i.e. implicit To EPR) -->
<send/>
</out>
</sequence>
<sequence name="errorHandler">
<makefault>
<code value="tns:Receiver" xmlns:tns="http://www.w3.org/2003/05/soap-envelope"/>
<reason value="COULDN'T SEND THE MESSAGE TO THE SERVER."/>
</makefault>
<header name="To" action="remove"/>
<property name="RESPONSE" value="true"/>
<send/>
</sequence>
</definitions>Objective: Demonstrate the session affinity based load
balancing with failover capability
Prerequisites:
Start Synapse with sample configuration 55 (i.e. synapse -sample 55).
Deploy the LoadbalanceFailoverService and start four sample Axis2 servers
on HTTP ports 9001, 9002, 9003 and 9004 respectively (make sure to specify
non-conflicting HTTPS ports).
This configuration also uses "simpleClientSession" to bind sessions as in
the previous sample. But failover endpoints are specified as the child
endpoints of the load balance endpoint. Therefore sessions are bound to
the failover endpoints. Session information has to be replicated among the
servers listed under each failover endpoint using some clustering
mechanism. Therefore, if one endpoint bound to a session failed,
successive requets for that session will be directed to the next endpoint
in that failover group. Run the client using the following command to
observe this behaviour.
ant loadbalancefailover -Dmode=session
You can see a client output as shown below.
...
[java] Request: 222 Session number: 0 Response from server: MyServer1
[java] Request: 223 Session number: 0 Response from server: MyServer1
[java] Request: 224 Session number: 1 Response from server: MyServer1
[java] Request: 225 Session number: 2 Response from server: MyServer3
[java] Request: 226 Session number: 0 Response from server: MyServer1
[java] Request: 227 Session number: 1 Response from server: MyServer1
[java] Request: 228 Session number: 2 Response from server: MyServer3
[java] Request: 229 Session number: 1 Response from server: MyServer1
[java] Request: 230 Session number: 1 Response from server: MyServer1
[java] Request: 231 Session number: 2 Response from server: MyServer3
...
Note that session 0 is always directed to MyServer1 and session 1 is
directed to MyServer3. No requests are directed to MyServer2 and MyServer4
as they are kept as backups by failover endpoints. Now shutdown the server
named MyServer1 while running the sample. You will observe that all
successive requests for session 0 is now directed to MyServer2, which is
the backup server for MyServer1's group. This is shown below, where
MyServer1 was shutdown after the request 534.
...
[java] Request: 529 Session number: 2 Response from server: MyServer3
[java] Request: 530 Session number: 1 Response from server: MyServer1
[java] Request: 531 Session number: 0 Response from server: MyServer1
[java] Request: 532 Session number: 1 Response from server: MyServer1
[java] Request: 533 Session number: 1 Response from server: MyServer1
[java] Request: 534 Session number: 1 Response from server: MyServer1
[java] Request: 535 Session number: 0 Response from server: MyServer2
[java] Request: 536 Session number: 0 Response from server: MyServer2
[java] Request: 537 Session number: 0 Response from server: MyServer2
[java] Request: 538 Session number: 2 Response from server: MyServer3
[java] Request: 539 Session number: 0 Response from server: MyServer2
...
<definitions xmlns="http://ws.apache.org/ns/synapse">
<sequence name="main">
<in>
<send>
<!-- get epr from the given wsdl -->
<endpoint>
<wsdl uri="file:repository/conf/sample/resources/proxy/sample_proxy_1.wsdl" service="SimpleStockQuoteService" port="SimpleStockQuoteServiceSOAP11port_http"/>
</endpoint>
</send>
</in>
<out>
<send/>
</out>
</sequence>
</definitions>Objective: Demonstrate the use of WSDL endpoints
Prerequisites:
Start the Synapse configuration numbered 56 (i.e. synapse -sample 56).
Deploy the SimpleStockQuoteService and start the sample Axis2 server.
This sample uses a WSDL endpoint inside the send mediator. WSDL endpoints
can extract endpoint's address from the given WSDL. As WSDL documents can
have many services and many ports inside each service, the service and
port of the required endpoint has to be specified. As with address
endpoints, QoS parameters for the endpoint can be specified in-line in the
configuration. An excerpt taken from the sample_proxy_1.wsdl containing
the specified service and port is listed below.
<wsdl:service name="SimpleStockQuoteService">
<wsdl:port name="SimpleStockQuoteServiceSOAP11port_http"
binding="axis2:SimpleStockQuoteServiceSOAP11Binding">
<soap:address location="http://localhost:9000/soap/SimpleStockQuoteService"/>
</wsdl:port>
<wsdl:port name="SimpleStockQuoteServiceSOAP12port_http"
binding="axis2:SimpleStockQuoteServiceSOAP12Binding">
<soap12:address location="http://localhost:9000/soap/SimpleStockQuoteService"/>
</wsdl:port>
</wsdl:service>
Specified service and port refers to the endpoint address
"http://localhost:9000/soap/SimpleStockQuoteService" according to the
above WSDL. Now run the client using the following command.
ant stockquote -Dsymbol=IBM -Dmode=quote -Daddurl=http://localhost:8280
Client will print the quote price for IBM received from the server running
on port 9000. Observe the Axis2 console and the Synapse console to verify
this behavior.
<definitions xmlns="http://ws.apache.org/ns/synapse">
<localEntry key="sec_policy" src="file:repository/conf/sample/resources/policy/policy_3.xml"/>
<in>
<send>
<endpoint name="secure">
<address uri="http://localhost:9000/soap/SecureStockQuoteService">
<enableSec policy="sec_policy"/>
<enableAddressing/>
</address>
</endpoint>
</send>
</in>
<out>
<header name="wsse:Security" action="remove"
xmlns:wsse="http://docs.oasis-open.org/wss/2004/01/oasis-200401-wss-wssecurity-secext-1.0.xsd"/>
<send/>
</out>
</definitions>Objective: Connecting to endpoints with WS-Security for
outgoing messages
Prerequisites:
You may also need to download and install the unlimited strength policy
files for your JDK before using Apache Rampart (e.g. see
http://java.sun.com/javase/downloads/index_jdk5.jsp)
Start the Synapse configuration numbered 100: i.e. synapse -sample 100
Start the Axis2 server and deploy the SecureStockQuoteService if not
already done
Use the stock quote client to send a request without WS-Security. Synapse
is configured to enable WS-Security as per the policy specified by
'policy_3.xml' for the outgoing messages to the SecureStockQuoteService
endpoint hosted on the Axis2 instance. The debug log messages on Synapse
shows the encrypted message flowing to the service and the encrypted
response being received by Synapse. The wsse:Security header is then
removed from the decrypted message and the response is delivered back to
the client, as expected. You may execute the client as follows:
ant stockquote -Dtrpurl=http://localhost:8280/
The message sent by Synapse to the secure service can be seen as follows,
when TCPMon is used.
POST http://localhost:9001/soap/SecureStockQuoteService HTTP/1.1
Host: 127.0.0.1
SOAPAction: urn:getQuote
Content-Type: text/xml; charset=UTF-8
Transfer-Encoding: chunked
Connection: Keep-Alive
User-Agent: Synapse-HttpComponents-NIO
800
<?xml version='1.0' encoding='UTF-8'?>
<soapenv:Envelope xmlns:xenc="http://www.w3.org/2001/04/xmlenc#" xmlns:wsa="http://www.w3.org/2005/08/addressing" ..>
<soapenv:Header>
<wsse:Security ..>
<wsu:Timestamp ..>
...
</wsu:Timestamp>
<xenc:EncryptedKey..>
...
</xenc:EncryptedKey>
<wsse:BinarySecurityToken ...>
<ds:SignedInfo>
...
</ds:SignedInfo>
<ds:SignatureValue>
...
</ds:SignatureValue>
<ds:KeyInfo Id="KeyId-29551621">
...
</ds:KeyInfo>
</ds:Signature>
</wsse:Security>
<wsa:To>http://localhost:9001/soap/SecureStockQuoteService</wsa:To>
<wsa:MessageID>urn:uuid:1C4CE88B8A1A9C09D91177500753443</wsa:MessageID>
<wsa:Action>urn:getQuote</wsa:Action>
</soapenv:Header>
<soapenv:Body xmlns:wsu="http://docs.oasis-open.org/wss/2004/01/oasis-200401-wss-wssecurity-utility-1.0.xsd" wsu:Id="Id-3789605">
<xenc:EncryptedData Id="EncDataId-3789605" Type="http://www.w3.org/2001/04/xmlenc#Content">
<xenc:EncryptionMethod Algorithm="http://www.w3.org/2001/04/xmlenc#aes256-cbc" />
<xenc:CipherData>
<xenc:CipherValue>Layg0xQcnH....6UKm5nKU6Qqr</xenc:CipherValue>
</xenc:CipherData>
</xenc:EncryptedData>
</soapenv:Body>
</soapenv:Envelope>0<definitions xmlns="http://ws.apache.org/ns/synapse">
<in>
<RMSequence single="true" version="1.0"/>
<send>
<endpoint name="reliable">
<address uri="http://localhost:9000/soap/ReliableStockQuoteService">
<enableRM/>
<enableAddressing/>
</address>
</endpoint>
</send>
</in>
<out>
<header name="wsrm:SequenceAcknowledgement" action="remove"
xmlns:wsrm="http://schemas.xmlsoap.org/ws/2005/02/rm"/>
<header name="wsrm:Sequence" action="remove"
xmlns:wsrm="http://schemas.xmlsoap.org/ws/2005/02/rm"/>
<send/>
</out>
</definitions>Objective: Demonstrate the message exchange between Synapse and
the server using WS-ReliableMessaging (WS-RM)Prerequisites:
Deploy the ReliableStockQuoteService in the sample Axis2 server by
switching to the samples/axis2Server/src/ReliableStockQuoteService
directory and running the command 'ant'.
Start the sample Axis2 server on port 9000.
Start Synapse with the sample configuration 101 (i.e. synapse -sample
101).
In the above configuration, WS-RM is engaged to the endpoint using the
<enableRM/> tag. It is possible to engage WS-RM to both Address and
WSDL endpoints using this tag. In addition to the RM enabled endpoint,
RMSequence mediator is specified before the send mediator. This mediator
is used to specify the set of messages to be sent using a single RM
sequence. In this sample it is specified as single message per sequence.
It also specifies the version of the WS-RM to be used. Refer to the
Synapse configuration language documentation for more information about
the RMSequence mediator. RM related SOAP headers are removed form the
message in the out mediator as WS-RM message exchange takes place only between
the Synapse and the server. Now run the sample client using the following
command.
ant stockquote -Dsymbol=IBM -Dmode=quote -Daddurl=http://localhost:8280
You can observe the client output displaying the quote price for IBM as
follows:
[java] Standard :: Stock price = $189.2521262517493
There is no difference to be observed between the normal message exchange
and WS-RM enabled message exchange as far as client and server outputs are
considered. But if you look at the wire level messages, you would observe
additional WS-RM messages and WS-RM elements. Synapse, the initiator of
the RM sequence, first try to create a sequence by sending a message with
CreateSequence element.
...
<soapenv:Body>
<wsrm:CreateSequence xmlns:wsrm="http://schemas.xmlsoap.org/ws/2005/02/rm">
<wsrm:AcksTo>
<wsa:Address>http://www.w3.org/2005/08/addressing/anonymous</wsa:Address>
</wsrm:AcksTo>
<wsrm:Offer>
<wsrm:Identifier>urn:uuid:546F6F33FB7D8BBE351179807372769</wsrm:Identifier>
</wsrm:Offer>
</wsrm:CreateSequence>
</soapenv:Body>
...
Sample Axis2 server responds to CreateSequence request with the following
message:
...
<soapenv:Body>
<wsrm:CreateSequenceResponse xmlns:wsrm="http://schemas.xmlsoap.org/ws/2005/02/rm">
<wsrm:Identifier>urn:uuid:879853A6871A66641C1179807373270</wsrm:Identifier>
<wsrm:Accept>
<wsrm:AcksTo>
<wsa:Address>http://localhost:9000/soap/ReliableStockQuoteService</wsa:Address>
</wsrm:AcksTo>
</wsrm:Accept>
</wsrm:CreateSequenceResponse>
</soapenv:Body>
...
Once the sequence is established, Synapse sends the request to the server
with the pre-negotiated sequence ID.
<soapenv:Envelope xmlns:wsa="http://www.w3.org/2005/08/addressing"
xmlns:soapenv="http://schemas.xmlsoap.org/soap/envelope/">
<soapenv:Header>
<wsa:To>http://localhost:9000/soap/ReliableStockQuoteService</wsa:To>
<wsa:MessageID>urn:uuid:DB9A5257B637DDA38B1179807372560712002-1515891720</wsa:MessageID>
<wsa:Action>urn:getQuote</wsa:Action>
<wsrm:Sequence xmlns:wsrm="http://schemas.xmlsoap.org/ws/2005/02/rm"
soapenv:mustUnderstand="1">
<wsrm:Identifier>urn:uuid:879853A6871A66641C1179807373270</wsrm:Identifier>
<wsrm:MessageNumber>1</wsrm:MessageNumber>
<wsrm:LastMessage/>
</wsrm:Sequence>
</soapenv:Header>
<soapenv:Body>
<m0:getQuote xmlns:m0="http://services.samples/xsd">
<m0:request>
<m0:symbol>IBM</m0:symbol>
</m0:request>
</m0:getQuote>
</soapenv:Body>
</soapenv:Envelope>
Synapse keeps on sending above message till the server responds with a
valid response message with 200 OK HTTP header. If the server is not ready
with a response, it will respond with 202 Accepted HTTP header for all
requests. Once the server is ready with a response it will send the
response message with sequence ID as follows.
<soapenv:Envelope xmlns:wsa="http://www.w3.org/2005/08/addressing"
xmlns:soapenv="http://schemas.xmlsoap.org/soap/envelope/">
<soapenv:Header>
<wsa:MessageID>urn:uuid:879853A6871A66641C1179807373804</wsa:MessageID>
<wsa:Action>http://services.samples/ReliableStockQuoteServicePortType/getQuoteResponse
</wsa:Action>
<wsa:RelatesTo>urn:uuid:DB9A5257B637DDA38B1179807372560712002-1515891720</wsa:RelatesTo>
<wsrm:Sequence xmlns:wsrm="http://schemas.xmlsoap.org/ws/2005/02/rm"
soapenv:mustUnderstand="1">
<wsrm:Identifier>urn:uuid:546F6F33FB7D8BBE351179807372769</wsrm:Identifier>
<wsrm:MessageNumber>1</wsrm:MessageNumber>
<wsrm:LastMessage/>
</wsrm:Sequence>
<wsrm:SequenceAcknowledgement xmlns:wsrm="http://schemas.xmlsoap.org/ws/2005/02/rm"
soapenv:mustUnderstand="1">
<wsrm:Identifier>urn:uuid:879853A6871A66641C1179807373270</wsrm:Identifier>
<wsrm:AcknowledgementRange Lower="1" Upper="1"/>
</wsrm:SequenceAcknowledgement>
</soapenv:Header>
<soapenv:Body>
<ns:getQuoteResponse xmlns:ns="http://services.samples/xsd">
...
Now both Synapse and the server are done with the actual message exchange.
Then Synapse sends a request to terminate the sequence as follows:
<soapenv:Envelope xmlns:wsa="http://www.w3.org/2005/08/addressing"
xmlns:soapenv="http://schemas.xmlsoap.org/soap/envelope/">
<soapenv:Header>
<wsa:To>http://localhost:9000/soap/ReliableStockQuoteService</wsa:To>
<wsa:MessageID>urn:uuid:546F6F33FB7D8BBE351179807379591</wsa:MessageID>
<wsa:Action>http://schemas.xmlsoap.org/ws/2005/02/rm/TerminateSequence</wsa:Action>
<wsrm:SequenceAcknowledgement xmlns:wsrm="http://schemas.xmlsoap.org/ws/2005/02/rm"
soapenv:mustUnderstand="1">
<wsrm:Identifier>urn:uuid:546F6F33FB7D8BBE351179807372769</wsrm:Identifier>
<wsrm:AcknowledgementRange Lower="1" Upper="1"/>
</wsrm:SequenceAcknowledgement>
</soapenv:Header>
<soapenv:Body>
<wsrm:TerminateSequence xmlns:wsrm="http://schemas.xmlsoap.org/ws/2005/02/rm">
<wsrm:Identifier>urn:uuid:879853A6871A66641C1179807373270</wsrm:Identifier>
</wsrm:TerminateSequence>
</soapenv:Body>
</soapenv:Envelope>
Server responds to the sequence termination message, accepting to
terminate the sequence as follows.
<soapenv:Envelope xmlns:wsa="http://www.w3.org/2005/08/addressing"
xmlns:soapenv="http://schemas.xmlsoap.org/soap/envelope/">
<soapenv:Header>
<wsa:ReplyTo>
<wsa:Address>http://localhost:9000/soap/ReliableStockQuoteService</wsa:Address>
</wsa:ReplyTo>
<wsa:MessageID>urn:uuid:879853A6871A66641C1179807380190</wsa:MessageID>
<wsa:Action>http://schemas.xmlsoap.org/ws/2005/02/rm/TerminateSequence</wsa:Action>
</soapenv:Header>
<soapenv:Body>
<wsrm:TerminateSequence xmlns:wsrm="http://schemas.xmlsoap.org/ws/2005/02/rm">
<wsrm:Identifier>urn:uuid:546F6F33FB7D8BBE351179807372769</wsrm:Identifier>
</wsrm:TerminateSequence>
</soapenv:Body>
</soapenv:Envelope>
Note that although each of above messages are separate SOAP messages, in
most cases they will be exchanged in a single socket connection as HTTP
Keep-Alive header is used.
<definitions xmlns="http://ws.apache.org/ns/synapse">
<proxy name="StockQuoteProxy">
<target>
<endpoint>
<address uri="http://localhost:9000/soap/SimpleStockQuoteService"/>
</endpoint>
<outSequence>
<send/>
</outSequence>
</target>
<publishWSDL uri="file:repository/conf/sample/resources/proxy/sample_proxy_1.wsdl"/>
</proxy>
</definitions>Objective: Introduction to Synapse proxy services
Prerequisites:
Start the Synapse
configuration numbered 150: i.e. synapse -sample 150
Start the
Axis2 server and deploy the SimpleStockQuoteService if not already done
Once Synapse starts, you could go to
http://localhost:8280/soap/StockQuoteProxy?wsdl and view the WSDL
generated for the proxy service defined in the configuration. This WSDL is
based on the source WSDL supplied in the proxy service definition, and is
updated to reflect the proxy service EPR.
Execute the stock quote client by requesting for a stock quote on the
proxy service as follows:
ant stockquote -Daddurl=http://localhost:8280/soap/StockQuoteProxy
An 'inSequence' or 'endpoint' or both of these would decide how the
message would be handled after the proxy service receives the message. In
the above example, the request received is forwarded to the sample service
hosted on Axis2. The 'outSequence' defines how the response is handled
before it is sent back to the client. By default, a proxy service is
exposed over all transports configured for Synapse, unless these are
specifically mentioned through the 'transports' attribute.
<definitions xmlns="http://ws.apache.org/ns/synapse">
<sequence name="proxy_1">
<send>
<endpoint><address uri="http://localhost:9000/soap/SimpleStockQuoteService"/></endpoint>
</send>
</sequence>
<sequence name="out">
<send/>
</sequence>
<endpoint name="proxy_2_endpoint">
<address uri="http://localhost:9000/soap/SimpleStockQuoteService"/>
</endpoint>
<localEntry key="proxy_wsdl" src="file:repository/conf/sample/resources/proxy/sample_proxy_1.wsdl"/>
<proxy name="StockQuoteProxy1">
<publishWSDL key="proxy_wsdl"/>
<target inSequence="proxy_1" outSequence="out"/>
</proxy>
<proxy name="StockQuoteProxy2">
<publishWSDL key="proxy_wsdl"/>
<target endpoint="proxy_2_endpoint" outSequence="out"/>
</proxy>
</definitions>Objective: Using custom sequences and endpoints for message
mediation with proxy services
Prerequisites:
Start the Synapse
configuration numbered 151: i.e. synapse -sample 151
Start the
Axis2 server and deploy the SimpleStockQuoteService if not already done
This configuration creates two proxy services. The first proxy service
'StockQuoteProxy1' uses the sequence named 'proxy_1' to process incoming
messages and the sequence named "out" to process outgoing responses. The
second proxy service 'StockQuoteProxy2' is set to directly forward
messages that are received to the endpoint named 'proxy_2_endpoint'
without any mediation.
You could send a stock quote request to each of these proxy services and
receive the reply generated by the actual service hosted on the Axis2
server instance.
ant stockquote -Daddurl=http://localhost:8280/soap/StockQuoteProxy1
ant stockquote -Daddurl=http://localhost:8280/soap/StockQuoteProxy2
<definitions xmlns="http://ws.apache.org/ns/synapse">
<proxy name="StockQuoteProxy" transports="https">
<target>
<endpoint>
<address uri="http://localhost:9000/soap/SimpleStockQuoteService" format="pox"/>
</endpoint>
<outSequence>
<send/>
</outSequence>
</target>
<publishWSDL uri="file:repository/conf/sample/resources/proxy/sample_proxy_1.wsdl"/>
</proxy>
</definitions>Objective: Switching transports and message format from SOAP to REST/POX
Prerequisites:
Start the Synapse
configuration numbered 152: i.e. synapse -sample 152
Start the Axis2 server and deploy the SimpleStockQuoteService if not
already done
This configuration demonstrates how a proxy service could be exposed on a
subset of available transports, and how it could switch from one transport
to another. This example exposes the created proxy service only on HTTPS,
and thus if the user tries to access it over HTTP, would result in a
fault.
ant stockquote -Dtrpurl=http://localhost:8280/soap/StockQuoteProxy
...
[java] org.apache.axis2.AxisFault: The service cannot be found for the endpoint reference (EPR) /soap/StockQuoteProxy
Accessing this over HTTPS (ant stockquote
-Dtrpurl=https://localhost:8243/soap/StockQuoteProxy) causes the proxy
service to access the SimpleStockQuoteService on the sample Axis2 server
using REST/POX. This could be seen if the message exchange was captured
using TCPMon as follows. The REST/POX response is now transformed back
into a SOAP message and returned to the client.
POST http://localhost:9000/soap/SimpleStockQuoteService HTTP/1.1
Host: 127.0.0.1
SOAPAction: urn:getQuote
Content-Type: application/xml; charset=UTF-8;action="urn:getQuote";
Transfer-Encoding: chunked
Connection: Keep-Alive
User-Agent: Synapse-HttpComponents-NIO
75
<m0:getQuote xmlns:m0="http://services.samples/xsd">
<m0:request>
<m0:symbol>IBM</m0:symbol>
</m0:request>
</m0:getQuote>HTTP/1.1 200 OK
Content-Type: application/xml; charset=UTF-8;action="http://services.samples/SimpleStockQuoteServicePortType/getQuoteResponse";
Date: Tue, 24 Apr 2007 14:42:11 GMT
Server: Synapse-HttpComponents-NIO
Transfer-Encoding: chunked
Connection: Keep-Alive
2b3
<ns:getQuoteResponse xmlns:ns="http://services.samples/xsd">
<ns:return>
<ns:change>3.7730036841862384</ns:change>
<ns:earnings>-9.950236235550818</ns:earnings>
<ns:high>-80.23868444613285</ns:high>
<ns:last>80.50750970812187</ns:last>
<ns:lastTradeTimestamp>Tue Apr 24 20:42:11 LKT 2007</ns:lastTradeTimestamp>
<ns:low>-79.67368355714606</ns:low>
<ns:marketCap>4.502043663670823E7</ns:marketCap>
<ns:name>IBM Company</ns:name>
<ns:open>-80.02229531286982</ns:open>
<ns:peRatio>25.089295161182022</ns:peRatio>
<ns:percentageChange>4.28842665653824</ns:percentageChange>
<ns:prevClose>87.98107059692451</ns:prevClose>
<ns:symbol>IBM</ns:symbol>
<ns:volume>19941</ns:volume>
</ns:return></ns:getQuoteResponse>
<definitions xmlns="http://ws.apache.org/ns/synapse">
<proxy name="StockQuoteProxy">
<target>
<inSequence>
<send>
<endpoint>
<address uri="http://localhost:9000/soap/SecureStockQuoteService"/>
</endpoint>
</send>
</inSequence>
<outSequence>
<send/>
</outSequence>
</target>
<publishWSDL uri="file:repository/conf/sample/resources/proxy/sample_proxy_1.wsdl"/>
</proxy>
</definitions>Objective: Routing the messages arrived to a proxy service
without processing the MustUnderstand headers (Security header)
Prerequisites:
You may also need to
download and install the unlimited strength policy files for your JDK
before using Apache Rampart (e.g. see
http://java.sun.com/javase/downloads/index_jdk5.jsp)
Start the Synapse configuration numbered 153: i.e. synapse -sample 153
Start the Axis2 server and deploy the SecureStockQuoteService if not
already done
The proxy service will receive secure messages with security headers which
are MustUnderstand. But hence element 'engageSec' is not present in the
proxy configuration Synapse will not engage that Apache Rampart on this
proxy service. It is expected that an MustUnderstand failure exception on
the AxisEngine would occur before the message arrives Synapse. But Synapse
handles this message and gets it in by setting all the headers which are
MustUnderstand and not processed to processed state. This will enable
Synapse to route the messages without reading the Security headers (just
routing the messages from client to service, both of which are secure). To
execute the client, send a stock quote request to the proxy service, and
sign and encrypt the request by specifying the client side security policy
as follows:
ant stockquote -Dtrpurl=http://localhost:8280/soap/StockQuoteProxy -Dpolicy=./../../repository/conf/sample/resources/policy/client_policy_3.xml
By following through the debug logs or TCPMon output, you could see that
the request received by the proxy service was signed and encrypted. Also,
looking up the WSDL of the proxy service by requesting the URL
http://localhost:8280/soap/StockQuoteProxy?wsdl reveals the security
policy attachments are not there and security is not engaged. When sending
the message to the backend service, you could verify that the security
headers were there as in the original message to Synapse from client, and
that the response received does use WS-Security, and forwarded back to the
client without any modification. You should note that this wont be a
security hole because the message inside Synapse is signed and encrypted
and can only be forwarded to a secure service to be useful.
<!-- A proxy service with a loadbalace endpoint -->
<definitions xmlns="http://ws.apache.org/ns/synapse">
<proxy name="LBProxy" transports="https http" startOnLoad="true">
<target faultSequence="errorHandler">
<inSequence>
<send>
<endpoint>
<session type="simpleClientSession"/>
<loadbalance algorithm="roundRobin">
<endpoint>
<address uri="http://localhost:9001/soap/LBService1">
<enableAddressing/>
<suspendDurationOnFailure>20</suspendDurationOnFailure>
</address>
</endpoint>
<endpoint>
<address uri="http://localhost:9002/soap/LBService1">
<enableAddressing/>
<suspendDurationOnFailure>20</suspendDurationOnFailure>
</address>
</endpoint>
<endpoint>
<address uri="http://localhost:9003/soap/LBService1">
<enableAddressing/>
<suspendDurationOnFailure>20</suspendDurationOnFailure>
</address>
</endpoint>
</loadbalance>
</endpoint>
</send>
<drop/>
</inSequence>
<outSequence>
<send/>
</outSequence>
</target>
<publishWSDL uri="file:repository/conf/sample/resources/proxy/sample_proxy_2.wsdl"/>
</proxy>
<sequence name="errorHandler">
<makefault>
<code value="tns:Receiver" xmlns:tns="http://www.w3.org/2003/05/soap-envelope"/>
<reason value="COULDN'T SEND THE MESSAGE TO THE SERVER."/>
</makefault>
<header name="To" action="remove"/>
<property name="RESPONSE" value="true"/>
<send/>
</sequence>
</definitions> Objective: Load Balancing with Proxy Services
Prerequisites: Sample setup is same as
LoadBalance endpoints (#53 to #54).
Start the Synapse configuration numbered 154: i.e. synapse -sample 154
Start the Axis2 server and deploy the SecureStockQuoteService if not
already done
Run the client with
ant loadbalancefailover -Dmode=session -Dtrpurl=http://localhost:8280/soap/LBProxy
Functionality is similar to the sample #54.
<definitions xmlns="http://ws.apache.org/ns/synapse">
<proxy name="StockQuoteProxy">
<target>
<endpoint>
<address uri="http://localhost:9000/soap/SimpleStockQuoteService">
<enableAddressing separateListener="true"/>
</address>
</endpoint>
<outSequence>
<send/>
</outSequence>
</target>
<publishWSDL uri="file:repository/conf/sample/resources/proxy/sample_proxy_1.wsdl"/>
</proxy>
</definitions>Objective: Demonstrate the dual channel invocation with Synapse proxy services
Prerequisites:
Start the Synapse
configuration numbered 150: i.e. synapse -sample 155
Start the
Axis2 server and deploy the SimpleStockQuoteService if not already done
This sample will show the action of the dual channel invocation within client and Synapse
as well as within Synapse and the actual server. Note that if you want to enable dual
channel invocation you need to set the separateListener attribute to true of the
enableAddressing element of the endpoint.
Execute the stock quote client by requesting for a stock quote on a dual channel from the
proxy service as follows:
ant stockquote -Daddurl=http://localhost:8280/soap/StockQuoteProxy -Dmode=dualquote
In the above example, the request received is forwarded to the sample service
hosted on Axis2 and the endpoint specifies to enable addressing and do the invocation
over a dual channel. If you observe this message flow by using a TCPmon, you could see that
on the channel you send the request to Synapse the response has been written as an
HTTP 202 Accepted, where as the real response from Synapse will come over a different channel
which cannot be obsesrved unless you use tcpdump to dump all the TCP level messages.
At the same time you can observe the behaviour of the invocation between Synapse and
the actual Axis2 service, where you can see a 202 Accepted message being delivered to Synapse
as the response to the request. The actual response will be delivered to Synapse over a
different channel.
<definitions xmlns="http://ws.apache.org/ns/synapse">
<localEntry key="sec_policy" src="file:repository/conf/sample/resources/policy/policy_3.xml"/>
<proxy name="StockQuoteProxy">
<target>
<inSequence>
<header name="wsse:Security" action="remove"
xmlns:wsse="http://docs.oasis-open.org/wss/2004/01/oasis-200401-wss-wssecurity-secext-1.0.xsd"/>
<send>
<endpoint>
<address uri="http://localhost:9000/soap/SimpleStockQuoteService"/>
</endpoint>
</send>
</inSequence>
<outSequence>
<send/>
</outSequence>
</target>
<publishWSDL uri="file:repository/conf/sample/resources/proxy/sample_proxy_1.wsdl"/>
<policy key="sec_policy"/>
<enableSec/>
</proxy>
</definitions>Objective: Using WS-Security signing and encryption with proxy
services through WS-Policy
Prerequisites:
You may also need to
download and install the unlimited strength policy files for your JDK
before using Apache Rampart (e.g. see
http://java.sun.com/javase/downloads/index_jdk5.jsp)
Start the Synapse configuration numbered 200: i.e. synapse -sample 200
Start the Axis2 server and deploy the SimpleStockQuoteService if not
already done
The proxy service expects to receive a signed and encrypted message as
specified by the security policy. Please see Apache Rampart and Axis2
documentation on the format of the policy file. The element 'engageSec'
specifies that Apache Rampart should be engaged on this proxy service.
Hence if Rampart rejects any request messages that does not conform to the
specified policy, those messages will never reach the 'inSequence' to be
processed. Since the proxy service is forwarding the received request to
the simple stock quote service that does not use WS-Security, we are
instructing Synapse to remove the wsse:Security header from the outgoing
message. To execute the client, send a stock quote request to the proxy
service, and sign and encrypt the request by specifying the client side
security policy as follows:
ant stockquote -Dtrpurl=http://localhost:8280/soap/StockQuoteProxy -Dpolicy=./../../repository/conf/sample/res
