The document discusses a rapid prototyping approach using Azure Functions for building an SMS-based survey system, highlighting the advantages of a serverless architecture with event-driven compute resources. It details the folder structure of a function app, configuration options, and the use of bindings for services like Service Bus. The document also addresses scaling options, function chaining, and the success of the prototype with a client.

1. Presented
By
WELCOME
MKEDOTNET

3. Rapid prototyping using Azure Functions -
A Walk on the Wild Side
Samrat Saha
08.29.2016

4. SMS Based Survey System
Users can text responses to a question
Users can opt in/out along with preferences
Topics that are time based
Automatic detection of topic
Start with a POC
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5. Traditional Approach
Way too many ways to skin this cat - prime concern is infrastructure
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6. Cloud Approach
● On-Demand
● Horizontal Scaling
● Paradigms (Paxos, Consistent Hashing, Redundancies, SLA’S!)
● Azure
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7. 7

8. Azure Functions
● Event driven on demand compute resources
● Serverless Architecture
● WebJobs SDK as a Service
● A function runs in the context of a Function App
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9. Bindings
● Triggers: HTTP, Events, Queues
● Input: Blob Storage, Table Storage, DocumentDB
● Output
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10. Function App Folder Structure
● WWWRoot
○ host.json
○ function1
• run.csx
• function.json
• bin
○ function 2
• run.csx
• function.json
• Bin
○ sharedAssemblies
• usefulAssembly.dll
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11. host.json
● Runtime specific config: Impacts entire function app
● Can set function timeouts, overall behaviors like service bus settings
{
"functionTimeout": "00:10:00"
}
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12. function.json
{
"bindings": [
{
"name": "queueItem",
"type": "serviceBusTrigger",
"direction": "in",
"queueName": "lc_incoming_sms_queue",
"connection": "lc_incoming_sms_read_connection",
"accessRights": "Listen"
},
{
"type": "serviceBus",
"name": "outputSbMsg",
"queueName": "lc_bluemix_results_queue",
"connection": "lc_bluemix_results_manage_connection",
"accessRights": "Manage",
"direction": "out"
}
],
"disabled": false
}
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13. run.csx
#r "../sharedAssemblies/LC-SMS-Quote-DomainModel.dll"
using System;
using System.Threading.Tasks;
using LC_SMS_DomainModel;
using LC_SMS_DomainModel.AzureLogging;
private static TraceWriter _logger;
public static void Run(string queueItem, out string outputSbMsg, TraceWriter log)
{
_logger = log;
log.Info($"C# ServiceBus queue trigger function processed message: {queueItem}");
AzureLogger.InfoCallback = new AzureLogger.InfoDelegate(InfoDelegate);
LCSMSDomainModel domainModel = new LCSMSDomainModel();
domainModel.Init();
String response = domainModel.HandleIncomingSMS(queueItem);
outputSbMsg = response;
}
public static void VerboseDelegate(String message, String source){
_logger.Verbose(message);
}
public static void InfoDelegate(String message, String source=null){
_logger.Info(message);
}
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14. Leveraging External Assemblies
● Some namespaces like System automatically imported
● Framework assemblies (automatically available through Azure Functions
Hosting Environment)
#r “System.Web.Http"
● bin folder relative to function
#r “functionSpecificUsefuldll.dll"
● Shared assemblies in under webroot, accessible by relative path
#r "../sharedAssemblies/LC-SMS-Quote-DomainModel.dll"
● Inside assembly to access config:
String storageAccountId = Environment.GetEnvironmentVariable(CONFIG_STORAGE_ACCOUNT,EnvironmentVariableTarget.Process);
● Use Project.Json for NuGet
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15. Scaling
● App Service Plan: Dedicated VM, leverage under utilized resources, good for
long running
● Dynamic Service Plan: Function app instance...more instances can be added
dynamically. Best use for intermittent/ short running
● Parallel Execution: Single threaded function runtime-> Scale to multiple
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16. Function Chaining
● Call a function from another
● Message Queue allows for decoupling
● Allows for semi-pure functional programming
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17. Where does this leave us?
● Prototype being worked on (for this example)
● People loved it...got sold to a client
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18. 1

19. Thanks
Centare
LC
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