Sajith Ravindra's Blog: May 2014

Thursday, May 29, 2014

Increasing Timeout period of the Callout Mediator/Message Forwarding Processor of WSO2 ESB

When you use Callout mediator and Message Forwarding Processor in WSO2 ESB it makes a blocking call to the back end service using org.apache.axis2.client.ServiceClient. If the service takes too much time to respond it will cause a timeout at ESB and will produce the following error in ESB,

java.net.SocketTimeoutException: Read timed out
        at java.net.SocketInputStream.socketRead0(Native Method)
        at java.net.SocketInputStream.read(SocketInputStream.java:129)
        at java.io.BufferedInputStream.fill(BufferedInputStream.java:218)
        at java.io.BufferedInputStream.read(BufferedInputStream.java:237)
        at org.apache.commons.httpclient.HttpParser.readRawLine(HttpParser.java:78)
        at org.apache.commons.httpclient.HttpParser.readLine(HttpParser.java:106)
        at org.apache.commons.httpclient.HttpConnection.readLine(HttpConnection.java:1116)
        at org.apache.commons.httpclient.MultiThreadedHttpConnectionManager$HttpConnectionAdapter.readLine(MultiThreadedHttpConnectionManager.java:1413)
        at org.apache.commons.httpclient.HttpMethodBase.readStatusLine(HttpMethodBase.java:1973)
        at org.apache.commons.httpclient.HttpMethodBase.readResponse(HttpMethodBase.java:1735)
        at org.apache.commons.httpclient.HttpMethodBase.execute(HttpMethodBase.java:1098)
        at org.apache.commons.httpclient.HttpMethodDirector.executeWithRetry(HttpMethodDirector.java:398)
        at org.apache.commons.httpclient.HttpMethodDirector.executeMethod(HttpMethodDirector.java:171)
        at org.apache.commons.httpclient.HttpClient.executeMethod(HttpClient.java:397)
        at org.apache.axis2.transport.http.AbstractHTTPSender.executeMethod(AbstractHTTPSender.java:622)
        at org.apache.axis2.transport.http.HTTPSender.sendViaPost(HTTPSender.java:193)
        at org.apache.axis2.transport.http.HTTPSender.send(HTTPSender.java:75)
        at org.apache.axis2.transport.http.CommonsHTTPTransportSender.writeMessageWithCommons(CommonsHTTPTransportSender.java:451)
        at org.apache.axis2.transport.http.CommonsHTTPTransportSender.invoke(CommonsHTTPTransportSender.java:278)
        at org.apache.axis2.engine.AxisEngine.send(AxisEngine.java:442)
        at org.apache.axis2.description.OutInAxisOperationClient.send(OutInAxisOperation.java:398)
        at org.apache.axis2.description.OutInAxisOperationClient.executeImpl(OutInAxisOperation.java:224)
        at org.apache.axis2.client.OperationClient.execute(OperationClient.java:149)
        at org.apache.axis2.client.ServiceClient.sendReceive(ServiceClient.java:554)
        at org.apache.axis2.client.ServiceClient.sendReceive(ServiceClient.java:530)
        at org.apache.synapse.mediators.builtin.CalloutMediator.mediate(CalloutMediator.java:221)
        at org.apache.synapse.mediators.AbstractListMediator.mediate(AbstractListMediator.java:71)
        at org.apache.synapse.mediators.base.SequenceMediator.mediate(SequenceMediator.java:114)
        at org.apache.synapse.mediators.eip.Target.mediate(Target.java:121)
        at org.apache.synapse.mediators.eip.splitter.IterateMediator.mediate(IterateMediator.java:132)
        at org.apache.synapse.mediators.AbstractListMediator.mediate(AbstractListMediator.java:71)
        at org.apache.synapse.config.xml.AnonymousListMediator.mediate(AnonymousListMediator.java:30)
        at org.apache.synapse.mediators.filters.FilterMediator.mediate(FilterMediator.java:143)
        at org.apache.synapse.mediators.AbstractListMediator.mediate(AbstractListMediator.java:71)
        at org.apache.synapse.mediators.base.SequenceMediator.mediate(SequenceMediator.java:114)
        at org.apache.synapse.mediators.eip.Target.mediate(Target.java:121)
        at org.apache.synapse.mediators.eip.splitter.IterateMediator.mediate(IterateMediator.java:132)
        at org.apache.synapse.mediators.AbstractListMediator.mediate(AbstractListMediator.java:71)
        at org.apache.synapse.mediators.base.SequenceMediator.mediate(SequenceMediator.java:114)
        at org.apache.synapse.mediators.eip.Target.mediate(Target.java:121)
        at org.apache.synapse.mediators.eip.splitter.IterateMediator.mediate(IterateMediator.java:132)
        at org.apache.synapse.mediators.AbstractListMediator.mediate(AbstractListMediator.java:71)
        at org.apache.synapse.mediators.base.SequenceMediator.mediate(SequenceMediator.java:114)
        at org.apache.synapse.mediators.eip.Target.mediate(Target.java:121)
        at org.apache.synapse.mediators.eip.splitter.IterateMediator.mediate(IterateMediator.java:132)
        at org.apache.synapse.mediators.AbstractListMediator.mediate(AbstractListMediator.java:71)
        at org.apache.synapse.mediators.base.SequenceMediator.mediate(SequenceMediator.java:114)
        at org.apache.synapse.core.axis2.ProxyServiceMessageReceiver.receive(ProxyServiceMessageReceiver.java:162)
        at org.apache.axis2.engine.AxisEngine.receive(AxisEngine.java:180)
        at org.apache.axis2.transport.http.HTTPTransportUtils.processHTTPPostRequest(HTTPTransportUtils.java:172)
        at org.apache.synapse.transport.nhttp.ServerWorker.processEntityEnclosingMethod(ServerWorker.java:455)
        at org.apache.synapse.transport.nhttp.ServerWorker.run(ServerWorker.java:275)
        at org.apache.axis2.transport.base.threads.NativeWorkerPool$1.run(NativeWorkerPool.java:172)
        at java.util.concurrent.ThreadPoolExecutor$Worker.runTask(ThreadPoolExecutor.java:886)
        at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:908)
        at java.lang.Thread.run(Thread.java:662)

To avoid this error you must increase the timeout period of org.apache.axis2.client.ServiceClient used by ESB. By default it has a timeout period of 30000ms (30s).

In order to increase the timeout period you have to set values(in milliseconds) of ,

SO_TIMEOUT
CONNECTION_TIMEOUT

parameters of the transport sender.

Your transport sender must look like this after you setting the parameters,

<transportSender name="http">
...
...
  <parameter name="SO_TIMEOUT">45000</parameter>
  <parameter name="CONNECTION_TIMEOUT">45000</parameter>
  ...
  ...
</transportSender>

If you are using HTTPS same parameters have to be set in the https transport sender as well.

For WSO2 ESB 4.8.0 or higher you must set these values in <ESB_HOME>/repository/conf/axis2/axis2_blocking_client.xml. For other versions you have to change <ESB_HOME>/samples/axis2Client/client_repo/conf/axis2.xml

Monday, May 19, 2014

Avoiding "Provider net.sf.saxon.TransformerFactoryImpl not found" error in Axis2

Scenario

When I'm trying to access the WSDL's of web services deployed in a Axis2 SOAP engine the following error is occurring,

javax.xml.transform.TransformerFactoryConfigurationError: Provider net.sf.saxon.TransformerFactoryImpl not found
    at javax.xml.transform.TransformerFactory.newInstance(Unknown Source)
    at org.apache.ws.commons.schema.XmlSchema.serialize_internal(XmlSchema.java:505)
    at org.apache.ws.commons.schema.XmlSchema.write(XmlSchema.java:478)
    at org.apache.axis2.description.AxisService2WSDL11.generateOM(AxisService2WSDL11.java:215)
    at org.apache.axis2.dataretrieval.WSDLDataLocator.outputInlineForm(WSDLDataLocator.java:131)
    at org.apache.axis2.dataretrieval.WSDLDataLocator.getData(WSDLDataLocator.java:73)
    at org.apache.axis2.dataretrieval.AxisDataLocatorImpl.getData(AxisDataLocatorImpl.java:81)
    at org.apache.axis2.description.AxisService.getData(AxisService.java:2980)
    at org.apache.axis2.description.AxisService.getWSDL(AxisService.java:1653)
    at org.apache.axis2.description.AxisService.printWSDL(AxisService.java:1421)
    at org.wso2.carbon.core.transports.util.Wsdl11Processor$1.printWSDL(Wsdl11Processor.java:43)
    at org.wso2.carbon.core.transports.util.AbstractWsdlProcessor.printWSDL(AbstractWsdlProcessor.java:86)
    at org.wso2.carbon.core.transports.util.Wsdl11Processor.process(Wsdl11Processor.java:57)
    at org.wso2.carbon.transport.nhttp.api.NHttpGetProcessor.processWithGetProcessor(NHttpGetProcessor.java:137)
    at org.wso2.carbon.transport.nhttp.api.NHttpGetProcessor.process(NHttpGetProcessor.java:277)
    at org.apache.synapse.transport.nhttp.ServerWorker.run(ServerWorker.java:256)
    at org.apache.axis2.transport.base.threads.NativeWorkerPool$1.run(NativeWorkerPool.java:173)
    at java.util.concurrent.ThreadPoolExecutor$Worker.runTask(ThreadPoolExecutor.java:895)
    at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:918)
    at java.lang.Thread.run(Thread.java:662)
[2014-05-19 17:56:10,980] ERROR - DefaultHttpGetProcessor Error processing request
org.apache.axis2.dataretrieval.DataRetrievalException: Provider net.sf.saxon.TransformerFactoryImpl not found
    at org.apache.axis2.dataretrieval.AxisDataLocatorImpl.getData(AxisDataLocatorImpl.java:85)
    at org.apache.axis2.description.AxisService.getData(AxisService.java:2980)
    at org.apache.axis2.description.AxisService.getWSDL(AxisService.java:1653)
    at org.apache.axis2.description.AxisService.printWSDL(AxisService.java:1421)
    at org.wso2.carbon.core.transports.util.Wsdl11Processor$1.printWSDL(Wsdl11Processor.java:43)
    at org.wso2.carbon.core.transports.util.AbstractWsdlProcessor.printWSDL(AbstractWsdlProcessor.java:86)
    at org.wso2.carbon.core.transports.util.Wsdl11Processor.process(Wsdl11Processor.java:57)
    at org.wso2.carbon.transport.nhttp.api.NHttpGetProcessor.processWithGetProcessor(NHttpGetProcessor.java:137)
    at org.wso2.carbon.transport.nhttp.api.NHttpGetProcessor.process(NHttpGetProcessor.java:277)
    at org.apache.synapse.transport.nhttp.ServerWorker.run(ServerWorker.java:256)
    at org.apache.axis2.transport.base.threads.NativeWorkerPool$1.run(NativeWorkerPool.java:173)
    at java.util.concurrent.ThreadPoolExecutor$Worker.runTask(ThreadPoolExecutor.java:895)
    at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:918)
    at java.lang.Thread.run(Thread.java:662)
Caused by: javax.xml.transform.TransformerFactoryConfigurationError: Provider net.sf.saxon.TransformerFactoryImpl not found
    at javax.xml.transform.TransformerFactory.newInstance(Unknown Source)
    at org.apache.ws.commons.schema.XmlSchema.serialize_internal(XmlSchema.java:505)
    at org.apache.ws.commons.schema.XmlSchema.write(XmlSchema.java:478)
    at org.apache.axis2.description.AxisService2WSDL11.generateOM(AxisService2WSDL11.java:215)
    at org.apache.axis2.dataretrieval.WSDLDataLocator.outputInlineForm(WSDLDataLocator.java:131)
    at org.apache.axis2.dataretrieval.WSDLDataLocator.getData(WSDLDataLocator.java:73)
    at org.apache.axis2.dataretrieval.AxisDataLocatorImpl.getData(AxisDataLocatorImpl.java:81)
    ... 13 more

Reason

In one of the web service deployed in my server, it has used Saxon XML transformer implementation instead of default java XML transformer implementation. Therefore, in it's code it has added the following static initialization block

1
2
3

static{
    System.setProperty("javax.xml.transform."net.sf.saxon.TransformerFactoryImpl");
}

The setting of this system property is the reason for this error. Also some can set this system property from command line using -Djavax.xml.transform.TransformerFactory=cnet.sf.saxon.TransformerFactoryImpl

Workaround

Remove the above static initialization block which sets the javax.xml.transfrom system property. Then, when instantiating TransfromFactory in the code, explicitly instantiate the saxon trasform factory with the full qualified class name as follows,

1	TransformerFactory fact = new net.sf.saxon.TransformerFactoryImpl()

In this way still you can use the Saxon transform implementaion without casuing any complications. When the system property is set, all the instantiations of transform factories which not uses the full qualified name of the transform factory class will be initialized with net.sf.saxon.TransfromerFactoryImpl and then it might lead to errors if they assume the default java xml transform implementation.

After recompiling and deployed the service the exception was not thrown