This slide deck discusses how to troubleshoot an issue in WSO2 Enterprise Integrator and follow best practices in order to optimize output and avoid failure. Watch webinar here: https://wso2.com/library/webinars/2018/10/troubleshooting-and-best-practices-with-wso2-enterprise-integrator

1. Troubleshooting and Best Practices
with WSO2 Enterprise Integrator
Hasitha Abeykoon - Associate Technical Lead
1
Shakila Sivagnanarajah - Software Engineer

2. Agenda
• Overview
• Monitoring Logs
• Monitoring Messages
• Timeout Configurations
• Best Practices
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3. Overview

4. What is Enterprise Integrator?
•
4

5. Integration Flow
Short-running Integration Flows
5

6. Monitoring Logs

7. Debug Logs
Enable Debug Logs
• Only few simple steps
- Shutdown the EI server
- open log4j.properties file from a text editor. The log4j.properties file is
located at <EI_HOME>/conf directory.
- Set log level to debug for log4j.category.org.apache.synapse as follows
log4j.category.org.apache.synapse=DEBUG
- Start EI server
• This will print useful information related to the mediation flow inside EI.
We can use this log for troubleshooting
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8. Debug Logs
Sample Debug Logs
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9. Trace Logs
• Trace logs trace the entire path when a message travels along a mediation
sequence.
• Tracing can be enabled for a proxy or for a sequence. This can be done by
adding the following attribute for the proxy/sequence configuration;
trace="enable"
• When tracing is enabled, trace logs can be seen from the
wso2-ei-trace.log file.
• This will provide more fine grained information than the debug logs
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10. Trace Logs
Sample Trace Logs
•
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11. Monitoring Messages

12. Monitoring Messages
Why message monitoring ?
• While developing integration scenarios with the EI, sometimes we might
get into situations where the expected results are not received for the
service invocations.
– Message payload sent by the EI is not in the format that is expected
by the backend service
– The content type of the sent message is not supported by the
backend service
– Some of the required headers like ‘Authorization Header’ is missing in
the request sent from the EI.
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13. Monitoring Messages
How to monitor messages ?
• To inspect messages passed in the connections, we can
use three mechanisms.
– TCPMon
– WireLogs
– Wireshark
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14. Monitoring with TCPMon
• Users can view and monitor the messages passed along a
TCP-based conversation using the TCPMon utility.
• We can use TCPMon tool to monitor messages going
through http transport towards EI and from EI.
• TCPMon is an Apache project distributed under Apache 2.0
License.
• TCPMon is not dependent on any third party libraries.
• Its user interface is based on a swing UI and works on
almost all platforms that support Java.
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15. Monitoring with TCPMon
Starting TCPMon
• To run the TCPMon available with your WSO2 Carbon product pack:
1. Go to <PRODUCT_HOME>/bin directory of your product pack.
2. Execute the following command to run the tool.
For Windows
tcpmon.bat
For Linux
./tcpmon.sh
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16. Monitoring with TCPMon
A sample:
• There are two connections
– Client-to-Proxy Service connection
– Proxy-to-Backend Server connection
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Proxy Service
8280 9000
Backend ServerClient

17. Monitoring with TCPMon
Monitoring Client to EI Connection
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Proxy Service
8280 9000
Backend ServerClient
TCPMon
8281

18. Monitoring with TCPMon
Monitoring Client
to EI Connection
18
Proxy
service

19. Monitoring with TCPMon
Monitoring EI to Backend Connection
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Proxy Service
8280
9000
Backend ServerClient
TCPMon
9001

20. Monitoring with TCPMon
Monitoring EI to
Backend Connection
20
Proxy
service

21. Monitoring with TCPMon
Limitations
• Can monitor only HTTP (no HTTPS)
• Hard to use in a production system
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22. Wirelogs
• WireLogs functionality is also used to monitor the
messages flowing through WSO2 EI over http
transport.
• It has the following advantages over TCPMon tool
– Can monitor messages going through https transport
– Do not need to change the synapse configuration
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23. Wirelogs
Enable WireLogs
• You can enable wire logs by following these steps
– Shutdown the EI server
– Open log4j.properties file from a text editor. This file is located at the
<EI_HOME>/conf directory.
– Uncomment the following entry;
– Start the EI server
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log4j.logger.org.apache.synapse.transport.http.wire=DEBUG

24. Wirelogs

25. Wirelogs
Reading a WireLog
• To read a wire log, first we have to identify the message direction.
DEBUG - wire >> - Represent the message coming into the EI from the wire
DEBUG - wire << - Represent the message going into the wire from the EI
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Proxy Service
8280 9000
Backend ServerClient
1 2
34

26. Wirelogs
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Proxy Service
8280 9000
Backend ServerClient
1 2
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27. Wireshark
• Wireshark is a network protocol analyzer captures packets in
real time and display them in human-readable format.
• Packet capture can provide information about individual
packets such as transmit time, source, destination, protocol
type and header data.
• Can monitor both HTTP and HTTPS requests
• No configuration changes needed
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28. Wireshark
Data captured
for a sample
request
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29. Timeout
Configurations

30. Troubleshooting Timeout Issues
Having a good understanding in different timeout configurations will certainly
help with troubleshoot issues.
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Proxy Service
8280 9000
Backend ServerClient
HTTP Listener
(http.socket.timeout)
Timeout Handler
(synapse.global_timeout_interval)
Endpoint
(timeout)
HTTP Listener
(http.socket.timeout)

31. Troubleshooting timeout issues
Client-to-Proxy Connection Timeout Parameters
http.socket.timeout
● In the client-to-proxy connection we have to consider only one
configuration parameter. That is http.socket.timeout
● This represents the socket timeout value of the passthrough http/https
transport listener.
● This can be configured from the passthru-http.properties file.
● The default value is 180000.
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32. Troubleshooting timeout issues
Proxy-to-Backend Connection Timeout Parameters
http.socket.timeout:
● This represents the socket timeout value of the passthrough http/https
transport sender. This is the same parameter used in transport listener.
Endpoint timeout:
● This is the timeout configuration parameter which can be configured at the
endpoint level.
● It allows us to configure different timeout values for different endpoints.
● For endpoints that doesn’t have a timeout configuration, the global
parameter value is considered as the timeout duration.
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33. Troubleshooting timeout issues
Proxy-to-Backend Connection Timeout Parameters
synapse.global_timeout_interval:
● Synapse registers a callback for each backend service invocation.
● When the response is received, the registered callback is used to correlate
it with the request.
● If the backend server does not respond back, the TimeoutHandler will
clear the corresponding registered callback from the callback store.
● The ‘synapse.global_timeout_interval’ parameter represents the time
duration that a callback should be kept in the callback store.
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34. Troubleshooting timeout issues
Proxy-to-Backend Connection Timeout Parameters
● Follow the formula
● Set the http.socket.timeout to a value higher than all other endpoint
timeout values.
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Socket Timeout > max(Global endpoint timeout, Timeout of individual endpoints)

35. Best Practices

36. Designing the Solution
• Use the proper naming convention from the start.
• To create and manage artifacts, use WSO2 Enterprise Integrator Tooling
• Create specific ESB projects for specific use cases.
• If an ESB project contains many artifacts related to multiple use cases,
name the artifacts by prefixing or post fixing the use case name.
• Highly cohesive (strength of relationship among features in a module)
• Loosely coupled (interdependencies among modules)
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<ProjectName>_<FileName>_<FileType>.<Extension>
Ex: Student_Student_Sequence.xml, Stocks_StockQuote_FileInbound.xml

37. Reusability of Configurations
• Improves readability and reusability
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Sequence templatesEndpoint templates
<endpoint template="name" ...>
<parameter name="name"
value="value"/>
.....
</endpoint>
<call-template target="template" >
<parameter name="name"
value="value"/>
.....
</call-template>

38. Use of Mediators - Log Mediator
• When server runs smoothly -> shouldn’t print any logs
• But on an error -> should be enough logs to fix the
issue
• Use log mediators in fault sequences;
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<log level="custom">
<property name="text" value="An unexpected error occurred"/>
<property name="message" expression="$ctx:ERROR_MESSAGE"/>
<property name="code" expression="$ctx:ERROR_CODE"/>
<property name="detail" expression="$ctx:ERROR_DETAIL"/>
<property name="exception" expression="$ctx:ERROR_EXCEPTION"/>
</log>

39. Use of Mediators - Service Invocation
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proxy/REST API
invocation with a Send
mediator
proxy/REST API
invocation with a
Call/Callout mediator

40. Use of Mediators - No Mediators after
Send/Respond
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41. Use of Mediators - Loopback Mediator
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42. Use of Mediators - Sequence Mediator
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43. Behaviour of Fault Sequence - onError
sequence
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44. Behaviour of Fault Sequence - default
fault sequence
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45. Test Environment
• Identical to production
• Load/performance tests (replicate production
use-cases)
• Endurance tests (long running tests)
• UAT (User Acceptance Tests)
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46. THANK YOU
wso2.com
THANK YOU
wso2.com