SALESFORCE INTEGRATION ARCHITECTURE DESIGNER : Things to consider before appearing for this exam

I have completed "Salesforce Certified Integration Architecture Designer" exam last week and with this I have started my journey for "System Architect".

I have successfully completed "Application Architect" credentials and if you would like to prepare for that then refer below blogs:

Data Architecture and Management Designer : Exam preparation guide and tips
Sharing and Visibility Designer : Exam preparation guide and tips

I have started preparing for this exam 2 months back and started with Resource guide. It contains all the required links for salesforce documentation and videos related to this exam.

After completing the resource guide, i started with Architect Journey: Integration Architecture trailmix. Lots of content in trailmix are already covered in resource guide. Best thing about trailmix is thing you can mark what all topics you have covered.

Now I will specify different points you need to know before appearing for exams.

STREAMING API

• It is based on Publish/Scribe modal.
• Whenever you have to notify user in Salesforce UI or external system about any changes to records, then use this API. 
• By Using Streaming API, there is no need for external system to continuously pooling into salesforce to find any data updates.
• In Streaming API, you create a channel by creating "Push Topic" and external system subscribe to this channel.
• In "Push topic", you specify the query which identifies whether event will be generated for data change. Once event is generated , then it is evaluated based on conditions defined on "Push Topic" to identify whether notification needs to be send to channel or not.
• SOQL queries with relationship are not supported in "Push Topic".
• SOQL queries without Id in select statement are also not supported in "Push Topic". So you always need to add Id in select query.
• Connection between salesforce and external system is maintained through long pooling concept.
• Streaming API does not guarantee reliable delivery of notifications. Streaming servers do not maintain client state and do not keep track what is being delivered. 
• Streaming API maintains sharing and visibility of data for user. External system will only receive information based on User access in Salesforce.
• Streaming API sends information in JSON format.
• If salesforce server is stopped due to some reasons, then client has to create connection again. Also if messages are processed but not yet delivered, will be lost if salesforce server restarts or stopped working.
• Avoid sending multiple message in single request as there is limit of 23,768 bytes for HTTP request POST body.

BULK API

• Bulk API is used to either export or import large volume of data. 
• Bulk API is asynchronous process and data upload happen in parallel on servers.
• Parallel mode is default for Bulk API. 
• You may face "Record lock Errors" if using Bulk API in parallel mode. Try to group records based on parentIds to avoid record locking errors.
• If you still face "Record Lock Error" then use BULK API in serial mode.
• Currently base64 fields are not supported in queries with the Bulk API.
• You can monitor BULK API jobs via API or Admin setup (Web UI).
• A batch can have a Completed state even if some or all of the records have failed. If a subset of records failed, the successful records aren't rolled back. Likewise, even if the batch has a Failed state or if a job is aborted, some records could have been completed successfully.
• When you get the batch results, it's important to look at the Success field for each result row to ensure that all rows were processed successfully. If a record was not processed successfully, the Error column includes more information about the failure.

OUTBOUND MESSAGES

Refer below link for complete information about outbound message

Outbound Messages : Implementation Tips and Considerations

INTEGRATION PATTERNS

There are lot of question on identifying correct integration patterns. Different scenarios will be given and being integration architect, you need to specify correct pattern.

For example, if there is need to send information to external system which is reliable even if external system is down while sending information, then implement inbound integration.

For complete details on different integration patterns and their use case, please refer below URL:
Integration Patterns and Best Practices for Salesforce - Part 1
Integration Patterns and Best Practices for Salesforce - Part 2

DATA BACKUP PROCESS

• Use Bulk API, if you need to take salesforce data backup (large volume) in your data warehouse.
• SOAP API provides 2 methods (getUpdated() and getDeleted()) which can be used to backup data which is changed.
• The Replication API is the most reliable method for data replication. It includes two functions, getUpdated and getDeleted, the former describes newly created and updated records, while the latter indicates records that have been deleted.
• The API returns the ID of every changed object that is visible to you, regardless of what change occurred in the object, based on SystemModstamp field information if available.
• The replication API has a specific advantage that it is designed to make sure you can't miss records and won't retrieve duplicates, both of which are possible when directly querying based on CreatedDate or LastModifiedDate fields (because of in-flight transactions that won't appear in queries until they are fully committed).

NAMED CREDENTIALS Vs REMOTE SITE SETTINGS

• Whenever callout is performed from salesforce, then you need to specify the endpoint in remote site settings.
• System will give "Unauthorized endpoint URL" error if endpoint is not specified in remote site settings.
• A named credential specifies the URL of a callout endpoint and its required authentication parameters in one definition. To simplify the setup of authenticated callouts, specify a named credential as the callout endpoint.   
• If you specify the endpoint URLs in named credentials then no need to specify it in remote site settings.
• Named credentials simplify utilizing oAuth for apex callout and store credentials in maintainable way.
• If you have multiple orgs, you can create a named credential with the same name but with a different endpoint URL in each org.
• Named credentials support basic password authentication and OAuth 2.0.
• To reference a named credential from a callout definition, use the named credential URL. A named credential URL contains the scheme callout:, the name of the named credential, and an optional path. For example: callout:My_Named_Credential/some_path.
• Named Credential access is provided through profile or permission sets.

MIDDLEWARE (ETL TOOLS)

• Always prefer utilizing middleware if you want to integrate salesforce with multiple system.
• If there is need to extract and transform data from salesforce and then to send it to external system, then middleware is best option.
• Middleware helps in Orchestration, Error handling and logging. 

REST API

• REST API is synchronous in nature and follows Remote Process Invocation—Request and Reply pattern.
• This is general integration API. It supports XML and JSON. It is light weight. It is state less API.It works with access_token(using OAuth2.0) or session Id in HTTP header.
• HEAD method is used to retrieve resource metadata. GET method is used to fetch data, POST to create records, DELETE to delete record and PATCH to update record.
• PATCH method is not supported in HTTP request in apex so in endpoint URL specify parameter "_HttpMethod=PATCH"
• REST API can be used for small set of data.
• REST API support XML and JSON format.
• Workbench is bet tool to test Salesforce REST API resources.

CANVAS APPLICATION

• Canvas app is used to integrate external web applications inside salesforce UI.
• Canvas app can be used within VF page, chatter tab, publisher action, salesforce console, as a feed item and salesforce 1 navigation item.
• Force.com canvas provide ajax based javascript SDK that allow embed application to easily access salesforce data layer and provide UI integration capabilities.
• Canvas app is defined within connected app framework.
• Canvas allows use of  HTTP POST and HTTP GET.
• It use signed request as default authentication method (use HTTP POST).

CONNECTED APPS

• A connected app integrates an application with Salesforce using APIs. Connected apps use standard SAML and OAuth protocols to authenticate, provide single sign-on, and provide tokens for use with Salesforce APIs. In addition to standard OAuth capabilities, connected apps allow Salesforce admins to set various security policies and have explicit control over who can use the corresponding apps.
• Connected Apps are not available in all org but can be installed in all orgs.
• “Customize Application AND either Modify All Data OR Manage Connected Apps” permission is needed to read, create, update, or delete connected apps.
• Write a custom connected app handler in Apex to customize the behavior of the connected app. Create a class that extends the ConnectedAppPlugin Apex class, and associate it with the connected app. The class can support new authentication protocols or respond to user attributes in a way that benefits a business process.
• If you enter multiple callback URLs, at run time Salesforce matches the callback URL value specified by the app with one of the values in Callback URL. It must match one of the values to pass validation. Separate multiple callback URLs with line breaks.
• The callback URL field has a limit of 2000 characters, cumulatively. If you enter several URLs and they exceed this limit, create another connected app to manage more callback URLs.
• Connected app can be configured to receive push notifications.A push-enabled connected app can support only one mobile platform. To support push notifications on Android and iOS versions of your mobile app, create a connected app for each platform.

SALESFORCE TO SALESFORCE INTEGRATION

• Salesforce to Salesforce can be used to create this data sharing relationship. Salesforce to Salesforce is a natively supported feature of the Force.com platform, and easily enables two trading partners to share relevant data records between orgs.
• Enable the “Manage Connections” permission on the profile of the users in order to configure salesforce to salesforce.
• Salesforce to salesforce can not be used to connect sandbox with production.

CONCURRENT APEX ERRORS

If you are getting error saying "Unable to process request. Concurrent requests limit exceeded." then it means concurrent Apex requests exceed governor limitations for your Salesforce organization.

Cause:

• Poorly coded Apex
• Synchronous callouts from Visualforce pages
• Inefficient SOQL queries

Resolution

• Perform synchronous callout from VF pages (use continuation framework to avoid excessive concurrent Apex errors and decreased performance).
• Use efficient SOQL queries. Use the Query Plan Tool to validate and optimize SOQL performance.

LOGIN RATE EXCEEDED

Refer below URL to know more about this error
Sign in Error: 'Login Rate Exceeded'

CHATTER REST API

• Enables integration with Salesforce Chatter
• Give access to chatter feed and social data(users, groups, followers and files).
• Use this API if you want to integrate mobile apps with Chatter.
• Chatter REST API provide built in pagination(provides nextpageurl, previouspageurl and currentpageurl in response) and pre-aggregation of data from different objects.
• Chatter REST API provide structured data which can be used for rendering on website.
• Returned information is localized to the user's time zone and language.
• Rate limiting for Chatter REST API is per user, per application, per hour. The rate limiting for SOAP API and REST API is by organization.

SOAP API

• Just go through differences between Enterprise and partner WSDL.
• SOAP API also provide getUpdated() and getDeleted() methods which can be used for incremental data backup.
• SOAP API integrate at Application layer.
• SOAP queries return 500 records per batch and can return max of 2000 records.
• This API has concurrent API request limit.
• SOAP API provides CRM specific methods (like convertLead()), Utility methods (like getUserInfo(), setPassword() etc) and describe methods (like describeGlobal(), describeSobject() etc).

Security Considerations

• Use TLS protocol to create a secure channel between Salesforce and other system.
• Always base64 encode the data before performing the callout in apex to securely transport sensitive data from Salesforce over an unsecure network connection.
• Custom webservices do not enforce record sharing and visibility. Make sure you are not sending any sensitive data in custom webservices.

Custom Webservices/REST services

• If you want to built API through which external application can update multiple objects in salesforce, then create custom webservices or apex REST services.
• Make sure you are not passing sensitive data to external system while create custom webservices or Apex REST services as these run in system mode.
• If you need to send information combining from multiple object to external system then use custom webservices or apex REST services.

Hope this will help!!