Mule meetup Hyderabad

[21st Dec 2019]
[Exception Handling in Mule 4 & IoT with MuleSoft Demo]
[Hyderabad - India]

All contents © MuleSoft Inc.
Sensitivity: General
Agenda
2
 Introductions
 What is Exception handling
 How to do Exception Handling in Mule 4
 Error Handler
 On Error Continue , On Error Propagate
Try scope
 Raise Error
 Error handling generate by API-Kit Router
IoT with MuleSoft Demo
 Networking time

Introductions
3
• About the organizers:
A SHOW OF HANDS:
Who is new to this MeetUp?

Introductions
4
• About the sponsor & Introducing Guests :

Surprises!
5
• Thanks for your
enthusiasm …You earned
it .. off course FCFS 
• Be geared up for the
quiz sessions at the end
of each module! 

Speaker
6

What is Exception Handling
8
• An exception occurs when an unexpected event happens while
processing.
• Exception handling is the process of responding to exceptions when a
computer program runs.
• Exception handling attempts to gracefully handle these situations so
that a program (or worse, an entire system) does not crash.
• Exception handling can be performed at both the software (as part of
the program itself) and hardware levels (using mechanisms built into
the design of the CPU).

Different type of Errors/Exceptions
9
• In General Errors/Exceptions are categorized in 2 groups
– Message Exception
• Thrown with in a flow when mule event is involved
– System Exception
• Thrown with in a flow when no mule event is involved
• Error that occur
– During Mule Start up
– When connection to External system fails

[Exception Handling in Mule 4]

Message Exception Handling in Mule 4
11
• Like any programming language Mule also provide ways to handle
exception.
• In Mule we can handle the message exception at different level.
– At Project level using Default error handler
– At Project level using Custom Global error handler
– At Flow level in exception handling using On Error Continue and On Error
Propagate, Raise Error
– With in Flow or at processor level using try scope

Message Exception Handling in Mule 4
12
• When an event is being processed through a Mule flow that throws
an error
– Normal flow execution stops
– The event is passed to the first processor in the error handler

Information about error
13
• When a error is thrown, an error object is created
• Two of error object properties are
– error.description – a string
– error.errorType – an object
• Error type is identified by namespace and indentifier
– HTTP:UNATHORIZED

Error Type hierarchy
14
• Like in Java class/object follow hierarchy in mule error types also
follow hierarchy
• Each Error type has a parent
• The error type ANY is the most general parent like Object class is
the parent class of all the classes in java by default.

Error Type hierarchy reference
15

Error Handler in Java
17
Try {
//Processing
//...
//...
} Catch (err) {
//Catch exception and do processing
//...
//...
}

Default Global Error Handler
18
• If there is no error handling written at any of the levels, the Mule
Default Error Handler is used, which stops the execution of the
flow and logs the exception.
• The Mule Default Error Handler is not configurable but, can be
replaced by our Custom Global error handler by creating a
Configuration global element.

Custom Global Error Handler
19
• To handle errors at the application level, we can add an error handler
in the global.xml (or simply outside a flow).
• Then, create a Configuration element in the global elements, which
sets the Global Error Handler as the Default Error Handler.

On Error Propagate
21
• All processors within error handling scope are executed
• At the end of the flow
– Rest of the flow that threw error does not executed
– The error is rethrown up to the next level and handled there
• An HTTP listener return error response with default status code 500

Visualize On Error Propagate like Java
22
Try {
//Processing
//...
//...
} Catch (err) {
//...
//Re-Thorough error
}

On Error Continue
24
• All processor within error handling scope executed
• At the end of the flow
– Rest of the flow that threw error does not executed
– The event is passed up to the next level as if flow execution had completed
successfully
• An HTTP listener return success response with default status code
200

Visualize On Error Continue like Java
25
Try {
//Processing
//...
//...
} Catch (err) {
//...
//Success and continue normal path
}

Error handling scenario 0
27

Error handling scenario 0 - Execution
28

29

30

31

32

33

34

35

36

Let’s Play the Game of Errors!
15- scenarios

How Can we Make a For loop
keep Running even if a record
fails during looping ?

Handling errors with flow – Try Scope
40
• Using try scope we can handle error within a
flow
• Try scope give us more control to handle
error at processor level
• One and more processors can be added in
try scope
• Try scope have its own error handling
section

Handling errors with flow - Execution
41

Custom error types
42
• When you have same processor which can throw exception in a flow
at multiple places we can use custom error types to
distinguish/differentiate which component/processor have raised the
exception
• You assign custom namespace and identifier to differentiate them
from other existing types
• Do not use existing module namespaces

Raising custom errors
44
• Apart from mapping existing error to custom
error mule also provide to raise custom
exceptions
• Raise error give us freedom to raise custom
exception

Raising custom errors - Execution
45

[Error handling generate by
API-Kit Router]

Error handling generate by API-Kit Router
47
• By default, interfaces created with APIkit have error handlers with
multiple On Error Propagate scopes that handle API-kit errors
– The error scopes set HTTP status codes and response messages
• The main routing flow has six error scopes
– APIKIT: BAD_REQUEST > 400
– APIKIT:NOT_FOUND > 404
– APIKIT:METHOD_NOT_ALLOWED > 405
– APIKIT:NOT_ACCEPTABLE > 406
– APIKIT:UNSUPPORTED_MEDIA_TPYE > 415
– APIKIT: NOT_IMPLEMENTED > 501

Error handling generate by API-Kit Router
48
• In most cases the default
generated error scopes are
sufficient
• You can modify default
generated error scopes and
even can add new error scopes
as per your requirement

System Exception Handling in Mule 4
49
• System exceptions can be handled in mule using retry/reconnection
and Until Successful

Difference between Error Handling in Mule 3 & 4
50
Mule 4 Mule 3
On Error Continue, On Error Propagate, Try
Scope are new options available
Catch, Choice and Reference exception
strategy are the few option available
Error handling can be done at processor level
using try scope
It was not possible in Mule 3
Error Handling at sub-flow is possible using
try scope
Transaction are possible using try scope Rollback strategy need to use to undo
transaction in case of errors
Custom Errors can be raised using Raise
Error
Custom Error mapping of existing exception
is possible
Easier and more granular error handling is
possible
It was little bit difficult to implement error
handling

What is IoT
• The Internet of Things (IoT) is the network of physical devices,
vehicles, and other items embedded with electronics, software,
sensors, actuators, and network connectivity which enable these
objects to collect and exchange data.
• The Scope of IoT is not limited to just connecting things (device,
appliances,machines) to the Internet.
• IoT allows these things to communicate and exchange data
(control&information)

What is IoT + MuleSoft
• Mule engine can be embedded directly into IoT devices, which
enables data exchange for the devices by connecting to IoT cloud
services and backend apps in the cloud.
• The Mule Runtime engine can be used to expose APIs on any IoT
device. Mule APIs can be deployed on IoT devices and turn them
on and off.
• In this presentation we will discuss about IOT and how it can be
used with Mulesoft and how Mule APIs can be deployed on IoT
devices

54
IoT – MuleSoft – Use Case

55
IoT – MuleSoft – Use Case
RESTful Call by passing
receiver’s phoneNumber
Store The Details
Send SMS via Twilio
Sense The Temperature

Things Required :
IoT – MuleSoft Use Case
57
• Software Requirements:
– Rasbian OS - https://www.raspberrypi.org/downloads/raspbian/
– SD formatter - https://www.sdcard.org/downloads/formatter/
– Xming Display Server -https://xming.en.softonic.com/
– PuTTY - https://www.putty.org/
– WinSCP - https://winscp.net/eng/download.php
– Mule Standalone Server (4.2.2)

Things Required :
IoT – MuleSoft Use Case
58
• Hardware Requirements:

Procedure
Raspberry Pi Setup
60
Installation of Rasbian OS :
 Download Rasbian OS from https://www.raspberrypi.org/downloads/raspbian/
 Raspbian Buster with desktop and recommended software.
 Used 16gb SD card and format it using SD formatter.
 Unzip the downloaded OS and paste it in SD card

Procedure
Network & Sharing
62
Connecting to UI interface:
 2 ways to connect:
Via HDMI Cable
Via Ethernet
 We are going with Ethernet for this Demo!
 Connect Lan from your Raspberry Pi LAN port to Laptop LAN port. Power up your PI
 Open Network and Sharing and do necessary configurations.
 Use putty to connect to Rasbian PI
 Use Xming for UI
 Enable SSH

Network & Sharing
63

Network & Sharing
64

Network & Sharing
65

Network & Sharing
66
Xming Screen

Mule Standalone
Installation
67

Mule Standalone Installation
68
• Install Java 8 if not present (By default your Rasbian OS has latest version of Java )
• Create a user & a directory with necessary permissions.

69
• Download latest Mule Standalone (4.2.2 in this case)
• 2 ways we can :
– Download using Linux command :
Use mule@raspberrypi:/opt/mule $ tar zxf mule-standalone-4.2.2.tar.gz to unzip
– Go to Browser and Download zip directly from :
• https://www.mulesoft.com/lp/dl/mule-esb-enterprise
• Extract it using below command :
• mule@raspberrypi:/opt/mule $ unzip zxf mule-standalone-4.2.2.zip to unzip
mule@raspberrypi:~ $ cd /opt/mule
mule@raspberrypi:/opt/mule $ wget https://repository-
master.mulesoft.org/nexus/content/repositories/releases/org
/mule/distributions/mule-standalone/4.1.1/mule-standalone-
4.2.2.tar.gz

70
• Download latest Mule Standalone (4.2.2 in this case)
• 2 ways we can :
– Download using Linux command :
Use mule@raspberrypi:/opt/mule $ tar zxf mule-standalone-4.2.2.tar.gz to unzip
– Go to Browser and Download zip directly from :
• https://www.mulesoft.com/lp/dl/mule-esb-enterprise
• Extract it using below command :
• mule@raspberrypi:/opt/mule $ unzip zxf mule-standalone-4.2.2.zip to unzip
mule@raspberrypi:~ $ cd /opt/mule
mule@raspberrypi:/opt/mule $ wget https://repository-
master.mulesoft.org/nexus/content/repositories/releases/org
/mule/distributions/mule-standalone/4.1.1/mule-standalone-
4.2.2.tar.gz

71
• Additional Config Files Needed
mule@raspberrypi:/opt/mule $ wget https://download.tanukisoftware.c
om/wrapper/3.5.34/wrapper-linux-armhf-32-3.5.34.tar.gz
tar zxf wrapper-linux-armhf-32-3.5.34.tar.gz
mule@raspberrypi:/opt/mule $ cp ./wrapper-linux-armhf-32-3.5.34/lib/l
ibwrapper.so ./mule-standalone-4.2.2/lib/boot/libwrapper-linux-armhf-
32.so
mule@raspberrypi:/opt/mule $ cp ./wrapper-linux-armhf-32-3.5.34/lib/
wrapper.jar ./mule-standalone-4.2.2/lib/boot/wrapper-3.2.3.jar
mule@raspberrypi:/opt/mule $ cp ./wrapper-linux-armhf-32-3.5.34/bin/
wrapper ./mule-standalone-4.2.2/lib/boot/exec/wrapper-linux-armhf-3
2

72
• Edit the files:
mule@raspberrypi:/opt/mule $ cd ./mule-standalone-4.2.2/bin
mule@raspberrypi:/opt/mule/mule-standalone-4.2.2/bin $ vi mule
mule@raspberrypi:/opt/mule/mule-standalone-4.2.2/bin $ cd ../conf
mule@raspberrypi:/opt/mule/mule-standalone-4.2.2/conf $ vi wrapper.conf
# Initial Java Heap Size (in MB)
wrapper.java.initmemory=256
# Maximum Java Heap Size (in MB)
wrapper.java.maxmemory=512

73
Deploy :
mule@raspberrypi:/opt/mule/mule-standalone-4.2.2/conf $ cd ../bin
mule@raspberrypi:/opt/mule/mule-standalone-4.2.2/bin $ ./mule

Develop and Deploy
Mule Application
74

Develop Mule App
75

Required Python Scripts
Develop Mule App
76

PIN Configuration
Develop Mule App
77

PIN Configuration
Develop Mule App
78

Deploy app:
• As the Mule server is up and running, place the snapshot of your
application in apps folder.
Application is deployed!
Deploy Mule App
79
Let’s do a Live Demo

Pain Points!
Points to be remembered!
80
• Make sure you are working on Linux OS and you will need necessary permissions
on file to execute them.
• Java Installation
• Make sure you use Resistors and sensors properly
• Network Connectivity
• Be familiar with Linux commands

We are Good!
81

Take a stand !
83
• Nominate yourself for
the next meetup speaker
and suggest a topic as
well.

What’s next
84
• Share:
– Tweet/share in LinkedIn , facebook, Instagram with your pictures with the hashtag
#HyderabadMuleMeetup #MuleSoftMeetup
– Also use #BringMuleSoftConnectToHyderabad to reach our wish to MuleSoft 
– Invite your network to join: https://meetups.mulesoft.com/hyderabad/
• Feedback:
– Please fill out the slips with details like are you new to Mule? If so what technology you are
currently working , What makes you to think of adopting MuleSoft and what topic you are
expecting in future Meetups
– Contact MuleSoft at meetup@mulesoft.com for ways to improve the program
– Instagram Page for Hyderabad to be created
– Your Feedback is Food for us
• Our next meetup:
– Date: TBD
– Location: Hyderabad
– Topic: TBD

Networking time
Introduce yourself to your neighbors!

See you next time
Please send topic suggestions to the organizer

Mule meetup Hyderabad

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