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A telephone number is a specific number that telecommunication firms assign to their customers, thus permitting them to communicate via an upgraded method of routing destination codes. Telecom companies give whole numbers within the limits of regional or national telephone numbering plans. With more than five billion users of mobile phones around the world, phone number information is now a gold mine for government and business operations.

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Having the number of current and potential customers and marketing professionals opens up a wealth of opportunities for lead generation and CRM. The presence of customer numbers is an excellent way to boost marketing campaigns as it allows marketers to interact with their target audience via rich multimedia and mobile messaging. Therefore, gathering phone number information is vital to any modern-day marketing strategy. The strategies consumers can use to collect data from phone numbers include:

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* Acquiring phone numbers that are already available information from third-party service companies with the information.

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One of the critical advantages of phone number data is that it is created to reveal the geographic location of mobile users because phone numbers contain particular strings specific to a region or country that show the user’s precise position. This is useful in targeted campaigns, mainly where marketers target a specific area that can target their marketing efforts.

To prevent duplicates and improve accessibility, the phone number information is typically stored in the E164 international format, which defines the essential characteristics of a recorded phone number. The specifications that are followed in this format are the number code for the country (CC) and an NDC, a country code (CC), a national destination code (NDC), and the subscriber number (SN).

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The possibilities that can be made possible by the phone number information are endless. The availability of a phone number database means that companies worldwide can market their products directly to prospective customers without using third-party companies.

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What are data types similar that are similar to Phone Number Data?

Telephone Number Data is comparable with Address Data; Email Address Data, MAID Hashed Email Data, Identification Linkage Data, and Household-Level Identity Data. These categories of data are typically employed to aid in Identity Resolution and Data Onboarding.

Which are your most popular uses for Phone Number Data?

The top uses that involve Phone Number Data are Identity Resolution, Data Onboarding, and Direct Marketing.

Let’s say you’re running a business selling strategy that demands you to connect with the maximum number of people you can. If your job is laid off for you, it can often be challenging to determine what to do. First, you should create your list of prospective customers and then save your call data in an electronic database.

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Though you might believe that working with lists of telephone numbers and storing them in databases is all you need to launch a cold calling campaign, it’s not the case. Since a telephone number database could contain thousands or millions of leads, along with important data points about each potential customer, It is essential to adhere to the best practices for a Database of telephone numbers. Methods to avoid becoming overwhelmed or losing important data.

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After you’ve established the basis for success by acquiring high-quality lead lists and implementing dialers that can boost how many calls your team receives by up to 400 percent, you’re ready to become familiar with best practices for your industry. By adhering to a list of phones and best database practices, you’ll dramatically improve the odds that your team will succeed in the short and long term.

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Here are the best techniques for telemarketing databases that you should consider a priority to observe.

Get Organized
A well-organized UAE mobile phone directory includes contacts organized according to phone country, postal, area, city, and province. By narrowing your calls to only one of the criteria, it is possible to incorporate new business information into your list, then sort and retarget top leads.

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Create a strategy to manage your phone lists. Naturally, your organizational plan must be based on the purpose of your cold-calling campaign. Your business’s goals will affect the traits your most promising prospects have. Make a profile of the most appealing candidate based on the plans for your marketing campaign. Make sure you make your leads list to ensure that the candidates who best meet your ideal profile of a prospect are first on your list of leads. List.

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Determine Who Has Access to and edit your database
Your phone number list doesn’t only represent an investment in money but also a resource that your team can use to increase sales. Although your phone number list is essential because you bought it, it’s also advantageous due to the possibility that it can improve your bottom line. In this regard, you should think carefully about who has access to and control your database.

It is generally recommended to restrict the number of users who have access to your database to only those who use it to communicate with potential customers to achieve your campaign’s goals. If an individual is not active with your marketing campaign, then there’s no reason for them to gain access to your telephone number database.

It’s also advisable to restrict access to the database you have created; it’s best to allow editing privileges to people who require them. This generally means that you only give editing rights to agents that will be conducting cold calls. It will be necessary to modify the database to make changes to records and notes that could aid in subsequent calls.

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Create Your Database
Databases are knowledge centers that store information for sales personnel. They are vital to gain knowledge and share it with your sales staff. Even if it’s just to keep call notes, callback databases can help your sales team to achieve maximum value and benefit from lists of telemarketing calls.

As time passes, your phone number list will likely expand and include more contact numbers and information on your customers. When you get recommendations from your current prospects or purchase leads lists, or either, it’s essential to grow the size of your database to include as much data as you can to assist you in achieving your goals for the business in the near and far future and at every step in between.

4. Keep Your Database
Although you want your database to expand with time, you do not want it to contain obsolete or ineffective details. To keep your database from overloading with useless information, it’s essential to maintain it regularly, including removing old records and updating your prospective customers with their contact details.

One of the most effective ways to ensure your database is to ensure that it doesn’t contain numbers listed on the Do Not Call list. If you make a call to an address that is listed on a Do Not List, you could result in your business spending lots of money, perhaps even millions. With the free tools available online, think about scrubbing all your data against the Do Not Call registry at least twice yearly.

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Definition of an index for the FINDORDERHISTORY A QUERY

This table definition allows primary key-based reads as well as writes of Orders. It doesn’t however allow a query like findOrderHistory() which results multiple matches of orders sortable by age. This is due to the fact that as you’ll see later in this article this query makes use of it’s DynamoDB query() operation that requires a table to be equipped with an uncomposed primary key composed of two attributes that are scalar. The primary attribute is a parti-tion key. The partition key is known because DynamoDB’s Z axis scale (described in Chapter 1) utilizes it to choose the storage partition of an item. The other attribute is the sort key. An query() operation returns items with the partition key specified and an associated sort key within the range specified and also match the optional filter expression. The query() operation returns the items according to order indicated through the key to sort. bUAE Phone number address lists

FindOrderHistory() query function will return the consumer’s order history ordered by age. This means that it requires an initial key that contains the consumerID as the par-tition key and the orderCreationDate being the key to sort. It’s not logical to have (consumerId and the orderCreationDate) as the key in the ftgo-order-history tablesince it’s not unique. buy UAE Phone number database online

The answer is to use findOrderHistory() to access the database DynamoDB refers to as an additional index of the ftgo order-history table. This index contains (consumerId or orderCreationDate) as its key that is not unique. As with an RDBMS index it is also the DynamoDB index is automatically updated every time its table is changed. However, unlike an RDBMS index however, an DynamoDB index could contain non-key attributes. Non-key attributes boost performance because they are returned by the query which means that the application does not have to pull these attributes from the database. Additionally, as you’ll discover, they can be used to filter data. Figure 7.14 depicts the layout of the table, as well as the index. UAE Phone number database

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This findorderhistory() query operation comes with one parameter for filtering that defines the criteria for searching. One criteria is the age of the returned orders. This is simple to set up because the DynamoDB Query’s key condition expression can be used to restrict the range in the kind key. The other criteria for filtering correspond to non-key attributes, and can be achieved with a filter expression which is an Boolean expression. A DynamoDB Query operation only returns those items that meet this filtering expression. For example, to find Orders that are CANCELLED, the OrderHistoryDao-DynamoDb uses a query expression orderStatus = :orderStatus, where :orderStatus is a placeholder parameter. buy UAE Phone number database online

Keyword filter criteria are more difficult to implement. It is used to select customers whose restaurant’s names or menu items correspond to one of the keywords specified. The OrderHistoryDaoDynamoDb enables the keyword search by tokenizing the restaurant name and menu items and storing the set of keywords in a set-valued attribute called keywords. It identifies the items that are in line with the keywords applying a filter expression that makes use of the() function which, for instance, contains(keywords, keyword1) OR contains(keywordskeywords keywords, :keyword2) keyword1, where keyword2 are placeholders for the keyword you have specified. UAE Phone number database


Certain customers will be able to place an abundance of orders. This is why it makes sense for to use the FindOrderHistory() query to make use of pagination. The DynamoDB Query operation has an operation parameter pageSize which defines what the max number of items it can return. When there’s more data than that, the output of the query will have an attribute called Last-EvaluatedKey that is non-null. A DAO is able to retrieve an additional page data when it invokes the query by using an exclusiveStartKey setting to LastEvaluatedKey. UAE Phone number database providers

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As you will observe, DynamoDB doesn’t support position-based pagination. Therefore, Order History Service returns an opaque pagination token to its clients. Clients use this token to seek out another page in the results. UAE Phone number address lists

After having explained the procedure for querying DynamoDB in order to get orders from customers, lets examine how to add and update them. buy UAE Phone number database online

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Updating ORDERS

DynamoDB provides two options for updating and adding items The PutItem() as well as UpdateItem(). Its PutItem() operation creates or replaces an entire item with it’s primary key. In theory, OrderHistoryDaoDynamoDb could use this operation to insert and update orders. The main issue when the use of putItem() is making sure that updates for multiple items on the same item are correctly handled. UAE Phone number database

Take, for instance an instance when two event handlers at the same time try to modify the identical item. Each event handler calls OrderHistoryDaoDynamoDb to load the item from DynamoDB, change it in memory, and update it in DynamoDB using PutItem(). The event handler that handles one event could alter the changes that was made by the other handler. OrderHistoryDaoDynamoDb can prevent lost updates by using DynamoDB’s optimistic locking mechanism. A less complicated and efficient method is to utilize UpdateItem(). UpdateItem() method. UAE Phone number id list

This updateItem() operation changes the each attribute on the object, and creates the item, if needed. Since various event handlers update the different attributes of the item, the use of UpdateItem is logical. This is also more efficient since there’s no requirement to extract the order from the table. UAE Phone number database

One issue that comes with updating the database to respond an event is as we mentioned earlier, the process of identifying and eliminating duplicate events. Let’s take a look at how you can accomplish this using DynamoDB.


All the event handlers of Order History Service are independant. Each of them determines the attributes for the item in the order. Order History Service could, thus, simply avoid the issue of duplicate events. The disadvantage of ignoring the issue is that an Order item can sometimes become out-of-date. This is since an event processor which receives duplicate events will change the attributes of an Order item to their previous values. The order item won’t have the correct attributes until events later on are delivered. UAE Phone number id list

As mentioned earlier One way to stop the data from getting out of date is to identify and eliminate duplicate events. OrderHistoryDaoDynamoDb can detect duplicate events by recording in each item the events that have caused it to be updated. Then, it can use it’s UpdateItem() procedure’s conditional updating mechanism, which will update an item only when an event isn’t duplicate. UAE Phone number database

A conditional update can only be executed if a conditional expression is real. A condition expression determines if an attribute exists or is assigned an exact value. The Order-HistoryDaoDynamoDb DAO can track events received from each aggregate instance using an attribute called <><> whose value is the highest received event ID. A duplicate event occurs when the attribute is present and its value is lower than or equivalent to the ID of the event. The OrderHistoryDaoDynamoDb DAO uses this condi-tion expression: UAE Phone number id list


OR <><> < :eventId

The condition expression will only allow the update only if the attribute doesn’t exist , or the eventID is greater than the event ID that was processed the last time. ID.

For example, suppose an event handler receives a DeliveryPickup event whose ID is 123323-343434 from a Delivery aggregate whose ID is 3949384394-039434903. The name of the tracking attribute is Delivery3949384394-039434903. The event handler will take the event as duplicated when the value of the attribute is higher that or equivalent to 123323 343434. A operation called query() operation that is invoked in the event handler changes the Order item with this expression of condition: UAE Phone number database providers

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OR Delivery3949384394-039434903 < :eventId UAE Phone number address lists

Now that I’ve described the DynamoDB data model and query design, let’s take a look at OrderHistoryDaoDynamoDb, which defines the methods that update and query the

ftgo-order-history table.

The OrderHistoryDaoDynamoDb class

The OrderHistoryDaoDynamoDb class implements methods that read and write items in the ftgo-order-history table. Its update methods are invoked by OrderHistory-EventHandlers, and its query methods are invoked by OrderHistoryQuery API. Let’s look at the various methods that are available, beginning at the addingOrder() procedure. buy UAE Phone number database


AddOrder() method as shown in Listing 7.2 adds an order to the ftgo’s order-history table. It is a method that has two parameters: sourceEvent and order. The order parameter refers to that of the Order to add, which is derived by analyzing the OrderCreated event. The sourceEvent parameter includes the eventId as well as the ID and type of the aggregate that generated the event. It is used to implement conditionsal updates. UAE Phone number database

List 7.2 AddOrder() method is used to add or edits an order

public class OrderHistoryDaoDynamoDb … The key to the
@Override Order item to be updated
public variable. Boolean addOrder(Order order Optional eventSource) {
UpdateItemSpec spec = new UpdateItemSpec()
.withPrimaryKey(“orderId”, order.getOrderId())
The update .withUpdateExpression(“SET orderStatus = :orderStatus, ” +
“creationDate = :cd, consumerId = ;consumerId lineItems =” +
expression the meaning of which buy UAE Phone number database
Updates to the ” lineItems: keywords =:keywords RestaurantName is ” + UAE Phone number database
attribute “:restaurantName”)
.withValueMap(new Maps()
The values of the .add(“:orderStatus”, order.getStatus().toString())
placeholders in .add(“:cd”, order.getCreationDate().getMillis())
the update .add(“:consumerId”, order.getConsumerId())
expression .add(“:lineItems”, mapLineItems(order.getLineItems()))
.add(“:keywords”, mapKeywords(order))
.add(“:restaurantName”, order.getRestaurantName())



return idempotentUpdate(spec, eventSource);


This addOrder() method generates an UpdateSpec that makes up the AWS SDK and describes the update process. When you have created the UpdateSpec it invokes idempotent-Update() which is a helper method that executes the update following the addition of an expres-sion of condition that protects from duplicate updates. buy UAE Phone number database

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NotePickedUp() method, as shown in listing 7.3. notePickedUp() procedure that is shown in figure 7.3 It is called through the handler of the DeliveryPickedUp event. It changes the delivery status of the order item to PICKED_UP. UAE Phone number database

The listing 7.3 NotePickedUp() method alters the status of the order to PICKED_UP

public class OrderHistoryDaoDynamoDb …

@Override UAE Phone number database providers

public void notePickedUp(String orderId, Optional eventSource) { UpdateItemSpec spec = new UpdateItemSpec()

.withPrimaryKey(“orderId”, orderId)

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.withUpdateExpression(“SET #deliveryStatus = :deliveryStatus”)

.withNameMap(Collections.singletonMap(“#deliveryStatus”, UAE Phone number database for sale


.withValueMap(Collections.singletonMap(“:deliveryStatus”, DeliveryStatus.PICKED_UP.toString())) email marketing database UAE Phone number

.withReturnValues(ReturnValue.NONE); idempotentUpdate(spec, eventSource); UAE Phone number database

The method works similarly to addingOrder(). This method generates an UpdateItemSpec, and activates IdempotentUpdate(). Let’s examine the IdempotentUpdate() method.


The following table outlines the IdempotentUpdate() method that is able to update the item by including a conditional expression in the UpdateItemSpec to guard from duplicate update. email marketing database UAE Phone number

7.4 Listing 7.4 The IdempotentUpdate() method is able to ignore duplicate events.

public class OrderHistoryDaoDynamoDb …

private boolean idempotentUpdate(UpdateItemSpec spec, Optional eventSource) { UAE Phone number database

{try You can try it.

table.updateItem( -> es.addDuplicateDetection(spec))


Return true;

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} catch (ConditionalCheckFailedException e) {

Do not make any false claims;


If the sourceEvent is supplied, idempotentUpdate() invokes SourceEvent.add-DuplicateDetection() to add to UpdateItemSpec the condition expression that was described earlier. The idempotentUpdate() method catches and ignores the ConditionalCheckFailedException, which is thrown by updateItem() if the event was a duplicate. email marketing database UAE Phone number

After we’ve looked at the code used to update tables, we can take a look into the method used to query.


The findOrderHistory() method, shown in listing 7.5, retrieves the consumer’s orders by querying the ftgo-order-history table using the ftgo-order-history-by-consumer-id-and-creation-time secondary index. It is a two-part method: the consumerId is the identifier for the customer while filter specifies the criteria for searching. This method generates Query-Spec, which is, just like UpdateSpec forms part of AWS SDK. It takes its parameters it queries the index and then transforms the results to an order history object. UAE Phone number consumer database

Listing 7.5 The findOrderHistory() method locates the orders of a consumer that are matched

public class OrderHistoryDaoDynamoDb …


public OrderHistory findOrderHistory(String consumerId, OrderHistoryFilter filter) { UAE Phone number database
The query must be completed
querySpec spec = new queryspec() returns the order of orders UAE Phone number database providers
of advancing of
.withHashKey(“consumerId”, consumerId)

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.withRangeKeyCondition(new RangeKeyCondition(“creationDate”)

.gt(filter.getSince().getMillis())); UAE Phone number database for sale

filter.getStartKeyToken().ifPresent(token -> The maximum
spec.withExclusiveStartKey(toStartingPrimaryKey(token))); age of the UAE Phone number consumer database
Orders to
Map valuesMap = to create a new HashMap <>(); returns

String filterExpression = Expressions.and( keywordFilterExpression(valuesMap, filter.getKeywords()),

statusFilterExpression(valuesMap, filter.getStatus()));

if (!valuesMap.isEmpty()) Construct a filter expression
spec.withValueMap(valuesMap); and placeholder value map
From the OrderHistoryFilter.
if (StringUtils.isNotBlank(filterExpression)) {

Limit the number of people
of outcomes if
The caller has indicated
A page size.
ItemCollection The result is index.query(spec);

Return to the new OrderHistory( UAE Phone number consumer database, false)








Create an Order using the results of the query.

After constructing the QuerySpec This method runs a query and creates an Order-History that contains the Orders list by analyzing the returned items.

The findOrderHistory() method implements pagination by serializing the value returned by getLastEvaluatedKey() into a JSON token. If a client specifies a start token in OrderHistoryFilter, then findOrderHistory() serializes it and invokes withExclusiveStartKey() to set the start key. UAE Phone number database

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As you will see, you need to tackle a variety of issues when you implement the CQRS view, such as selecting an appropriate database, creating a data model that effectively implements the updates as well as queries. It is also about managing simultaneous updates, and handling duplicate events. The most complex component in the program is called the DAO as it has to effectively handle concurrency and make sure that updates are irresistible. UAE Phone number database free


The implementation of queries to pull data from multiple sources is difficult since the data from each service is confidential.

There are two options to create these kinds of queries using API composition pattern and API composition pattern, and the Command query responsibility segregation (CQRS) pattern.

It is the API composition model, that collects information from multiple sources, provides the most efficient method to implement queries. It should be utilized whenever it is possible. UAE Phone number database free

A drawback to an API structure is the fact that some complicated queries need inefficient joins in memory of massive data sets. UAE Phone number database

The CQRS pattern that implements queries with the view database, is more effective however, it is more difficult to implement.

The CQRS view module has to handle multiple updates, as well as identify and eliminate duplicate events.

CQRS helps to separate the concerns by allowing a particular service to run the ability to return information owned by a different service.

Clients have to deal with the eventuality of the CQRS views. buy UAE Phone number database online

Patterns of APIs that are external to the public

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It is the FTGO application, as well as many other applications, uses an REST API. Its clients include FTGO mobile apps, JavaScript running in the browser, as well as applications created by the partners. In a monolithic structure it is the API that is accessible for clients’ use will be an monolith’s API. However, once the FTGO team has begun to deploy microservices, it’s no longer an API as each service has their own API. Mary as well as her group have to determine which API the FTGO application should be able to expose to its customers. For instance, should customers be aware of the services and submit requests directly to them? UAE Phone number database for sale

The process of creating an API for applications is made more difficult due to the variety of its clients. Different clients usually require different information. Desktop browsers’ UI typically displays more details than mobile applications. Additionally, different clients access the services through different types of networks. Clients inside the firewall make use of a high-performance network, while those outside the firewall utilize an internet connection or mobile networks and will experience lesser performance. Therefore, as you’ll discover that it’s not always a good idea to make sense to provide an API that is a one-size-fits-all. UAE Phone number database
This chapter begins by explaining the various external API design problems. I then discuss some of the other outside API patterns. I discuss an API gateway pattern, then the API gateway pattern first, then the pattern for Back-ends that frontends. Then, I will examine the steps to design and build the API gateway. I look at the various options offered, including available API gateways off the shelf and frameworks to build your own. I explain the concept and development for an API gateway built using an Spring Cloud Gateway frame-work. I also explain how to construct an API gateway with GraphQL the framework that uses graphs to create a query language. UAE Phone number database free

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Design issues with APIs that are external to the design

To explore the different API-related issues we’ll look at one of them: the FTGO application. As Figure 8.1 illustrates, the application’s APIs are utilized by various customers. Four kinds of users use the APIs of the service:

Web-based applications, for instance consumer web applications, which provides the browser-based UI that consumers can use Restaurant web application that implements the browser-based UI for restaurants as well as Admin web app, that provides the internal administrator user interface

JavaScript applications running inside the browser UAE Phone number business database free download

Mobile applications, one specifically for customers and the other for couriers UAE Phone number database

Applications developed by third-party developers

The web-based applications are within the firewall, which means they can access the service via the high-bandwidth, low-latency network. Other clients operate without firewalls, and they can access the services via the internet with a lower bandwidth, but higher latency as well as mobile networks.

One way to approach API design is to allow clients to call the API directly. On the surface, this sounds quite straightforward–after all, that’s how clients invoke the API of a monolithic application. However, this technique is not often employed in microservice architecture due to the following issues:

The APIs for service that are fine-grained will require users to submit multiple requests to get the information they require that is not efficient and can lead to an unsatisfactory user experience. UAE Phone number business database free download

The inability to encapsulate that results from clients having knowledge of the APIs of each service makes it difficult to alter the architecture and APIs.

Services may utilize IPC mechanisms that aren’t a good fit or feasible for clients to utilize, particularly clients that aren’t part of the firewall.

API design issues related to issues with API design for FTGO mobile client UAE Phone number database

Customers use this FTGO Mobile client in order to manage and place their orders. Imagine you’re designing the clients View Order view which shows an order. In chapter 7, you will learn that the information displayed in this view contains basic information about the order, like its status, status of payment as well as the status of the purchase from the point of view of the restaurant as well as delivery information, which includes the location of the order and the estimated delivery time if it is in the process of being delivered. UAE Phone number business database free download

This monolithic edition of FTGO application comes with an API endpoint which returns the order information. The mobile client obtains the information it requires by making a single request. However, in this microservices variant of FTGO application the details of an order are like the ones previously mentioned and are scattered across a variety of services, such as: UAE Phone number database

Order Service–Basic order details including the order details, as well as status

Kitchen Service – The status of the order from the perspective of the restaurant and the estimated date it is ready for pickup

Delivery Service – The order’s delivery status as well as its estimated delivery date and the current location buy UAE Phone number database online

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Accounting Service – The order’s payment status UAE Phone number database for sale

When the client on mobile calls the services directly, it should as Figure 8.2 illustrates, make multiple calls to retrieve the data.
In this case the mobile app serves as an API composer. It calls multiple APIs and then combines the results. While this method seems to be reasonable however, it is plagued by a number of serious issues. UAE Phone number database free download

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Poor user experience due to the client’s multiple requests

The main issue is that the mobile app has to make multiple requests to get the information it wishes to show before the end user. The tense interactions between the application and its services may cause the app to appear unresponsive particularly when it is using the internet or mobile networks. The internet has lower speed and lower latency than a traditional LAN, while mobile network are more prone to issues. The latency of mobile networks (and the internet) is generally 100 times greater than that of a network. UAE Phone number database

The greater latency may not pose a problem in retrieving order information since the mobile app reduces the time delay by processing the requests simultaneously. The response time for all requests is not more than the time of one request. However, in some situations the client might need to run requests sequentially and this can cause a negative user experience. UAE Phone number database free download

Furthermore, a the poor user experience caused by latency in the network isn’t the only problem with an API that is chatty. It also requires mobile developers to write potentially complicated API writing composition codes. This is a distraction from the primary goal of creating a fantastic user experience. Additionally, since each network request requires energy, a Chatty API drains mobile’s battery quicker.


Another disadvantage of the mobile app directly connecting to those services can be due to the absence of the encapsulation. When an application grows and develops, the creators of a service may alter an API in a manner that disrupts existing clients. They could even alter how the system is broken down into different services. Developers can introduce new services or separate or combine existing services. However, if information about the services is integrated into mobile applications it may be difficult to modify the APIs for the services. UAE Phone number database free download

As opposed to updating a server-side app it can take several hours, or possibly days to release the latest version of a mobile app. Apple or Google must be able to approve the update and then make it available to download. It is possible that users will not be able to download the upgrade right away, if ever. You may not be able to convince reluctant users to download the upgrade. The approach of exposing APIs for services to mobile devices can be a significant barrier to the development of those APIs. UAE Phone number database

Services could make use of CLIENT-UNFRIENDLY MECHANISMS

Another problem with a mobile application that calls services directly is that certain service providers might use protocols that can’t be readily accessible to a client. Applications that run without firewalls typically employ protocols like HTTP as well as WebSockets. However, as explained in Chapter 3, developers of services can choose a variety of protocols from, not only HTTP. Certain of the services offered by an application could use gRPC, while others might utilize the AMQP messaging protocol. These protocols work effectively internally, but may not be able to be used by mobile devices. Some aren’t even compatible with firewalls. buy UAE Phone number database online

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API design issues that apply to other types of clients

I decided to use the mobile client as it’s an excellent opportunity to highlight the negatives of cli-ents gaining access to services directly. However, the issues that arise from the openness of services to cli-ents isn’t exclusive to mobile clients. Other kinds of clients particularly those that aren’t protected by firewalls have the same issues. As we’ve mentioned earlier the FTGO applications’ services are used by web-based applications as well as clients that run on browsers, JavaScript applications, as well as third-party applications. Let’s examine the API design and design challenges that these buy UAE Phone number database for marketing clients face. UAE Phone number b2b database

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Traditional server-side web applications which manage HTTP queries from the browser, and then return HTML pages, operate within the firewall, and can access services via the internet. Latency and bandwidth aren’t an issue when it comes to the use of API composition within web applications. Web applications also can utilize non-web-friendly protocols for accessing the APIs. The teams who develop web applications are part the same group and typically work closely with the teams who write the backend software, therefore web applications can easily be updated when the backend services are modified. It is therefore possible for web applications to be able to connect to backend service directly. UAE Phone number database


Modern browsers employ a certain proportion of JavaScript. Even if HTML is created through a server-side web app it is commonplace to use JavaScript running within the browser to call services. For example, all of the FTGO application web appli-cations–Consumer, Restaurant, and Admin–contain JavaScript that invokes the back-end services. The consumer web application is one example. It automatically refreshes the order Details page by using JavaScript which invokes the APIs of the service. UAE Phone number b2b database

On the other side the applications that run on browsers JavaScript applications are simple to update as the APIs for ser-vices are changed. However, JavaScript applications that access the internet’s services are experiencing the same issues with latency issues on networks as mobile apps. This is not the only issue. browser-based UIs particularly those designed that are designed for desktops are generally more advanced and require many more features than mobile apps. It’s probable that Consumer and Restaurant applications, that access services via the internet, will not be able to write APIs for service effectively. UAE Phone number database


FTGO as well as other companies, provides an API for third-party developers. The developers can utilize this API FTGO API to create applications to manage and process orders. Third-party applications are able to access APIs on the internet, and API composition is likely to be inefficient. However, this inefficiency API composition can be a minor issue when compared with the larger issue of creating an API which is utilized by third-party software. This is because third-party developers require an API that’s reliable. UAE Phone number b2b database

Only a handful of organizations can make third-party developers change to a different API. Businesses with an unstable API are at risk of losing developers to competitors. So, it is important to control the development of an API that is utilized by developers from third parties. It is common to have to keep older versions up to some time, and possibly forever.

This is a major burden on an business. It’s not practical to hold the backend developers accountable for long-term backward compatibility. Instead of providing services directly to third party developers, businesses should use an independent API public that’s created by a separate team. In the next section, API gateways are public. API is developed through an architectural component referred to by the name of the API gateway. Let’s take a look at the way an API gateway operates. UAE Phone number b2c database

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Pattern API Gateway

As you’ve already observed, there are a variety of disadvantages to services connecting to services directly. It’s not always practical for clients to execute API creation over internet. Encapsulation isn’t available, which creates a challenge for programmers to alter APIs and decomposition of services. Sometimes, services employ protocols for communication that aren’t appropriate for use outside of firewalls. Therefore, a better option is to make use of API gateways. API gateway. UAE Phone number database

The API gateway an API service that acts as the gateway to the application from outside world. It’s responsible for routing requests, API composition, and other tasks, like authentication. This section focuses on API gateways and the API gateway design pattern. I will discuss its benefits as well as drawbacks. I also discuss the design considerations you need to consider when designing the API gateway. buy UAE Phone number database online

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A brief overview of API gateway pattern buy UAE Phone number database for marketing

Section 8.1.1 discussed the disadvantages of clients, including the FTGO mobile application that makes multiple requests to provide details to users. An alternative is to allow a client to send one inquiry to an API gateway, which is a service which acts as the primary gateway for API requests to an application that is not inside the firewall. This is similar to the Facade design pattern that is part of the object-oriented design. Similar to a facade, an API gateway wraps the internal architecture of the application and offers an API for its clients. It could also be charged with additional responsibilities, like monitoring, authentication, and limit on rate. UAE Phone number database

It is the API gateway that handles requests processing, the composition and routing of API requests and also for the translation of protocols. All API requests from clients outside start with API gateway. API gateway. The gateway forwards certain requests to the right service. The API gateway manages other requests by using an API composition pattern, and also by calling multiple services before gathering the results. It can be able to translate between protocols for clients like HTTP and WebSockets as well as non-client-friendly protocols that are used by the API services. UAE Phone number b2c database


One of the main purposes that the API gateway is to route requests. A API gateway performs API functions through routing request requests towards the appropriate service. When it receives a query it API gateway checks an routing map which specifies the service it will route the request. A routing map could include, for instance, mapping the HTTP method and its path towards an HTTP URL for a particular service. This is similar to the reverse proxy-ing functions that web servers offer, like NGINX. UAE Phone number database


An API gateway usually does more than just reverse proxying. It may also facilitate certain API operations by using API composition. API composition, for instance. FTGO API gateway is an example, as it implements an API operation called the Get Order Details API operation with API composition. As the figure 8.4 illustrates the mobile application sends an API request which retrieves order information from multiple sources.

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The FTGO API gateway is an API with a coarse-grained structure that allows mobile users to access the data they require in one request. For instance, the mobile client can make only one obtainOrderDetails() call to API gateway. UAE Phone number b2c database


An API gateway could also carry out the translation of protocols. It could provide a RESTful API external clients, despite the fact that the applications use various protocols internally, like REST and GRPC. In the event of need for implementation, some API operations is a translation between the external RESTful API and the internal gRPC APIs.

An API gateway can provide a single , one-size-fits-all (OSFA) API. The problem with one API is that clients may require different specifications. For example, a third-party application might need an API operation called the Get Order Details API operation to provide the entire information about the order, whereas mobile clients only require just a portion of the data. One approach to address this issue is to offer clients the option of specifying in their request which fields and objects should be returned by the server. This method is suitable for an open API that is required to support many different applications from third parties, but it doesn’t always give users the necessary control. UAE Phone number database

An alternative is to allow an API gateway to offer each client an individual API. For instance it’s possible that the FTGO API gateway could offer its FTGO mobile app with an API specifically created to meet the needs of its users. It might even offer distinct APIs for Android or iPhone mobile apps. The API gateway can also provide an API available to third-party developers to utilize. In the next post, I’ll discuss the Backends for Frontends pattern which takes the concept of an API-per-client further by creating a distinct API gateway to each of the clients.UAE Phone number customers database


While an API gateway’s primary duties include API composition and routing but it also has the ability to implement what’s termed edge functions. Edge functions are like an application that processes requests in the margins of an application. Examples of edge functions applications could implement are the following: UAE Phone number id list

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Authentication–Verifying the identity of the client making the request. buy UAE Phone number database for marketing

Authorization–Verifying that the client is authorized to perform that particular operation.

Limiting the number of requests per second you receive from an individual cli-ent, or from all clients.

Caching–Cache responses in order to decrease the amount of requests to the service. UAE Phone number customers database

Metrics collection: Collect metrics about API usage to be used for billing analytics. UAE Phone number database

Request logging–Log requests.

There are three possible areas in your application in which you can implement these functions on the edge. The first is to incorporate them in backend service. This could be a good idea for certain purposes like caching, metrics collection and maybe even the autho-rization process. But generally, it’s safer when the application authenticates requests in the edge before they are sent to the servers. UAE Phone number business database

Another alternative is to implement these edges functions as an edge service which is downstream of an API gateway. Edge services are the primary point of contact for clients from outside. They authenticate the requests and then performs other edge processing prior to sending it on to an API gateway. API gateway.

One of the benefits of having an edge-specific service is that it is able to separate the con-cerns. The API gateway concentrates exclusively on API routing, and compose. Another advantage is that it centralized the responsibility for crucial edges, such as authentication. This is especially important in the case of applications that have several API gateways that could be constructed using a variety frameworks and languages. I’ll go into more detail about this in the future. The downside of this method is that it can increase the network’s latency due to the additional hop. Additionally, it increases how complex the app. UAE Phone number database

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In the end it’s usually more convenient to choose the third option, and then implement these edge functions, specifically authorization, within the API gateway it self. One less hop on the network that improves the latency. There are less moving parts, which decreases the complexity. Chapter 11 discusses what happens when it works. API gateway and services work together to provide security.

An API module executes every API operation in two ways. Certain API operations map directly to a single API operation. API modules implement these functions through routing request to relevant Service API function. It could route requests by using an generic routing module that is able to read a configuration file that outlines these routing guidelines. UAE Phone number business database

An API module is a program that implements different more complicated API actions using API com-position. Implementation of the API operation is made up of custom code. Every API operation implementation manages requests by calling multiple services and combining the results.


A crucial question you need to answer is who is accountable for the development and operation of the API gateway as well as its operations? There are many possibilities. One option is for separate teams to handle API gateway development. API gateway. The disadvantage is that it’s very similar to SOA in that there was an Enterprise Service Bus (ESB) team was in charge of the entire ESB development. If an application developer working on mobile app requires access to a specific service, they have to submit an application for access to an API gateway team. API gateway group and then wait until they are able the API. This type of centralized bottleneck within the business is contrary to the ethos of the microservices architecture that encourages loosely coupled autonomous teams. UAE Phone number business database

An alternative, one that has been endorsed by Netflix suggests that the clients’ teams– the web, mobile, and public API teams – to control the API module that provides their API. The API gateway group is accountable for the development of the Common module as well as the operations for the gateway. The ownership model, which is illustrated in figure 8.6 provides the teams with the control over their APIs. UAE Phone number database

If a group needs to modify their API and they need to make sure to upload the modifications to the source repository of their API gateway. In order to work properly for API gateways, the API gateway’s deployment process must be completely automated. If not, the clients’ teams are often stuck by an API gateway to release the latest version. UAE Phone number id list

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One issue concerning the API gateway concerns that the responsibility for it is unclear. Many team members contribute to the source code. A API gateway group is accountable for its operation. Although not as bad as an SOA ESB, this blurring of roles is not in line with the microservices architecture principle of “if you create it you are the owner.” buy UAE Phone number database for marketing

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The solution is to have an API gateway for each client, the so-called Backends for front-ends (BFF) pattern, which was pioneered by Phil Calcado ( and his colleagues at SoundCloud. As as figure 8.7 illustrates every API module can be regarded as a independent API gateway, which is developed and maintained by a single client group. UAE Phone number Profile

Public API Team: The API team operates and owns the API gateway, while the mobile team is the one that operates their own and the list goes on. In theory, various API gateways could be created with different stacks of technology. But this can lead to the duplication of the code to implement common functions for example, the code used to implement edge functions. It is ideal that all API gateways should use the identical technology stack. The common feature includes a library shared by the API gateway team. that is implemented through an API gateway group. UAE Phone number database

Apart from clearly defining responsibilities in addition to clearly defining responsibilities, the BFF pattern offers other advantages. In addition to clearly defining responsibilities, the API modules are separated from each other and this improves the security. A misbehaving API won’t influence other APIs. This also increases observability since different API modules run distinct methods. Another advantage to using the BFF design is the fact that every API is scalable independently. This BFF pattern also helps reduce the time to start since the each API gateway has a smaller, more simple application. UAE Phone number Profile
The benefits of an API Gateway

One of the major benefits of the use of API gateways is that the API gateway is the fact that it provides a capsulization of the its internal structure. Instead of calling particular services or functions, the clients communicate directly to the API gateway. The API gateway supplies clients with a specific API, which decreases the number of trips between the application and client. The API gateway also makes it easier for clients to write code. UAE Phone number database


This API gateway pattern has certain drawbacks. It’s yet another accessible component that needs to be designed, implemented and managed. There’s also the chance it could happen that the API gateway will become a bottleneck in development. Developers have to upgrade the API gateway to allow their APIs to be exposed. It’s crucial that the process to update the API gateway is as light as is possible. In the event that it is not developers will have to wait in line to upgrade the gateway. Even with these limitations in the majority of real-world applications, it is sensible to make use of the API gateway. If needed, you could utilize this Backends for frontends design pattern to allow the teams to design and develop their APIs in a separate manner. UAE Phone number Profile

Netflix is an excellent example for an API gateway.

An excellent example to show an API gateway’s capabilities is an API gateway like the Netflix API. It is a Netflix streaming platform is accessible across a wide range of devices like televisions, Blu-ray players, smartphones and a myriad of other devices. Initially, Netflix attempted to have a one-size-fits-all style API for its streaming service ( why-rest-keeps-me-night/2012/05/15). However, the company quickly realized that it didn’t work because of the variety of devices and the different requirements. Nowadays, Netflix uses an API gateway that creates an individual API for every device. The client device team creates and oversees API implementation. API implementation. UAE Phone number database

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In the initial release of API Gateway every client team implemented their API by using Groovy scripts which handle API composition and routing. Each script called one or more APIs of the service by using Java client libraries that were provided by the teams that provide the services. One thing is for sure this is a good idea and the developers of client applications have created hundreds of scripts. It is true that the Netflix API gateway processes billions of requests every day, and every API call is distributed to the backend of six or seven services. However, Netflix has found this monolithic architecture to be quite difficult to use. UAE Phone number leads

In the end, Netflix has now shifted into an API gateway architecture that is similar to the Backends for frontends design. This new structure lets clients’ teams create API mod-ules with NodeJS. Each API module has in its very own Docker container, however these scripts do not invoke services directly. Instead, they trigger another “API gateway” that exposes the service APIs through Netflix Falcor. Netflix Falcor is an API technology that performs dynamic, declarative API composition, allowing the client to call multiple services in one request. This new technology provides a range of advantages. The API modules are separate from each other improving the reliability and observability, and the API module for clients is independent of the other modules, which makes it capable of scaling. UAE Phone number id list

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API gateway design issues

We’ve now looked at the API gateway design pattern and its advantages and drawbacks We’ll look at a variety of API gateway design challenges. There are many aspects to take into consideration when creating the API gateway: buy UAE Phone number targeted list

Scalability and performance

Maintainable code is written using reactive abstractions of programming UAE Phone number leads

Handling partial failure

Being a responsible citizen within the application’s design UAE Phone number database

We’ll go over each.


An API gateway acts as the front door of the application. Any external requests have to be processed by the gateway. Although the majority of companies aren’t operating on the same scale as Netflix that handles millions of requests every day however, the speed and capacity of the API gateway are usually crucial. One of the key design decisions that determines the performance and scale determines whether an API gateway is either synchronous or asynchronous I/O.

In the model of synchronous I/O every internet connection will be handled with a specific thread. This is a basic programming model that works well. For instance, it’s the foundation of the popular Java EE servlet framework, but this framework also offers the option of making the request by synchronously. One drawback of synchronous I/O is the fact that OS threads can be heavyweight therefore there is an limit to the amount of threads and consequently concurrent connections the API gate-way could have. UAE Phone number leads

The alternative is to employ the Asynchronous (nonblocking) I/O models . This model is where an event loop thread is responsible for distributing I/O events to handlers. There are a myriad of I/O technology that is asynchronous to pick from. In the JVM you can make use of some of these NIO-based frameworks, such for Netty, Vertx, Spring Reactor and JBoss Undertow. Another popular alternative that is not JVM-based is NodeJS which is a platform based using Chrome’s JavaScript engine. UAE Phone number database

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Nonblocking I/O is more flexible because it does not have the burden of having multiple threads. However, the drawback is the fact that an asynchronous callback-based programming model is more complicated. The code is harder to write, comprehend, and even debug. Event handlers have to return promptly to prevent blocking the thread for event loops. UAE Phone number listing

Furthermore, whether or not using nonblocking I/O provides a significant general benefit is contingent on the specifics of an API gateway’s request processing process. Netflix was not pleased with the outcomes when it revised Zuul its edge server, in order to utilize NIO
As you’d imagine the use of NIO decreased the cost of every network connection, because there’s no specific thread to run each. Additionally the Zuul cluster that was running I/O-intensive logic such as request routing had an increase of 25% in throughput, and an increase of 25% in the utilization of CPU. However Zuul’s clus-ter which used CPU-intensive logic such as compression and decryption–did not show any improvements. UAE Phone number database


As previously mentioned, API composition consists of calling multiple backend services. Certain backend service requests rely completely on the client’s parameters. Others may depend on outcomes of other service requests. One option is to use the API endpoint handler to use the API endpoint handler method according to the order determined by dependencies. For example, the below list shows the handler used of the FindOrder() request, which is constructed this way. It invokes each of the four services one after another. UAE Phone number listing

The order information is retrieved by calling backend service in succession


public class OrderDetailsController {


public OrderDetails getOrderDetails(@PathVariable String orderId)  UAE Phone number id list

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OrderInfo orderInfo = orderService.findOrderById(orderId);

TicketInfo ticketInfo = kitchenService


DeliveryInfo deliveryInfo = deliveryService


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.findBillByOrderId(orderId); UAE Phone number listing

OrderDetails orderDetails =

OrderDetails.makeOrderDetails(orderInfo, ticketInfo,

deliveryInfo, billInfo); UAE Phone number database

Return orderDetails


The downside of calling services in a sequential fashion is that the time to respond will be the total of all responses to the services. To minimize response time the composition logic must whenever it is possible, call services simultaneously. In this instance there are no dependencies on the services. All services must be invoked concurrently, which greatly reduces the time to respond. The problem is writing concurrent code that can be maintained. UAE Phone number lists

This is due to the fact that the most common method to write scalable concurrent code is by using callbacks. An event-driven, synchronous I/O is fundamentally dependent on callbacks. Even the server

API-based API composer that calls services simultaneously typically makes use of callbacks. It could execute requests concurrently by calling ExecutorService.submitCallable(). The issue is this approach results in an Future that has an API that is blocked. A more scalable approach is for an API composer to call ExecutorService.submit (Runnable) and for each Runnable to invoke a callback with the outcome of the request. The callback accumulates results and when all are received, it sends back the result back to the customer. UAE Phone number database

The process of writing API code with the conventional callback method that is synchronous quickly takes into callback hell. The code can be confusing complicated, hard to comprehend and prone to error, particularly when the composition is a combination of sequential and parallel requests. An alternative is writing API compose code using a declarative manner employing a reactive approach. Reactive abstractions that work with the JVM include: UAE Phone number lists

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Java 8 CompletableFutures

Project Reactor Monos

RxJava (Reactive Extensions to Java) The Observables were created by Netflix specifically to resolve this issue in its API gateway

Scala Futures

An API gateway based on NodeJS would make use of JavaScript promises, or RxJS which are reactive extensions for JavaScript. Utilizing one of these reactive abstractions allows you to create code that is simple and understandable. In this section, I will show an example of programming using Project Reactor Monos and version 5 of the Spring Framework.


Alongside being flexible In addition to being scalable, an API gateway should also be as reliable. One way to ensure reliability can be to have multiple gateway instances in the load balancer. If one fails, the load balancer will redirect requests to the remaining instances. UAE Phone number lists

Another way to be sure the API gateway is secure is to handle properly failures in requests and those which have unacceptable latency. If an API gateway is able to invoke the service, there’s possibility that the service will be inaccessible or slow. A gateway to APIs may have to be waiting for a long time, possibly for an indefinite amount of time waiting for a response which encapsulates resources and blocks it from communicating an answer to its client. A persistent request to a failing service could even consume a valuable resource, such as threads and cause the API gateway not being able to take on any additional requests. The solution, which is described in the chapter 3 is to instruct to configure an API gateway to employ the Cir-cuit breaker pattern while calling services. UAE Phone number database

Being a good CITIZEN in the field of architecture.

In chapter 3, I discussed the patterns used to discover services as well in Chapter 11 I will discuss patterns for observation. The patterns for discovering services allow the service client, for example, the API gateway to discover the location on the network of an instance of a service to be able to invoke it. The observability patterns permit developers to track the performance of an application and help to fix issues. API gateways, just like other services within the architecture, should use the patterns chosen for the architecture. UAE Phone number quality lists

Making an API Gateway

Let’s look at the steps to set up the concept of an API gateway. As previously mentioned the responsibilities that API gateways are as follows: API gateway is as the following:

Request routing – Routes requests to the services based on criteria like HTTP methods for requesting and the path. The API gateway should be able to route the request using it’s HTTP request method if the application is equipped with either one of or several CQRS queries. As we’ll see in chapter 7 In this type of architecture, the commands as well as queries will be dealt with by sepa-rate providers. UAE Phone number database

API composition–Implements a GET REST endpoint using the API composition pattern, described in chapter 7. The request handler integrates the results of calling multiple API services.

Edge functions–The most notable of these is the authentication. buy UAE Phone number database

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Protocol translation–Translates between client-friendly protocols and the client-unfriendly protocols used by services.

Being a responsible citizen within the application’s design. buy UAE Phone number targeted list

There are two various ways to create an API gateway.

Using an off-the-shelf API gateway product/service–This option requires little or no development but is the least flexible. For instance, an off-the-shelf API gateway will not allow API composition UAE Phone number quality lists

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Develop an own API gateway with either the API gateway platform or web frame-work for the beginning point. This can be the most adaptable way however it does require some work.

Let’s take a look at the options available, beginning with the use of an API gateway that is available off the shelf. solution or product.

Utilizing an API gateway that is off-the-shelf product or service UAE Phone number database

A variety of off-the-self products and services utilize API gateway capabilities. We’ll first take a look at some of the services provided by AWS. In the next section, I’ll talk about the various products can be downloaded, configured and then run your own.


AWS API gateway AWS API gateway, one of the many services offered via Amazon Web Services, is an application for deploying as well as managing APIs. AWS API gateway API AWS API gateway API represents a collection of REST resources that support either one or two HTTP methods. You can configure the API gateway to redirect each (Method resource, Method) to an backend service. A backend service can be one of the AWS Lambda Function, described in chapter 12, the application defined HTTP service and/or the AWS service. If you require, you can modify your API gateway in order to convert the request and response with templates-based mechanisms. It is possible to transform requests and responses using templates. AWS API gateway can also authenticate requests. UAE Phone number quality lists

AWS API gateway AWS API gateway fulfills some of the requirements required for an API gateway, which I mentioned earlier. This gateway for APIs is offered by AWS and therefore you are not accountable for the instal-lation process and operations. You can configure the API gateway then AWS manages everything else including scaling. UAE Phone number database

Unfortunately it’s true that the AWS API gateway has several shortcomings and limitations that make it to fall short of other specifications. It does not allow API composition, which means you’ll have to implement API composition into those backend applications. AWS API gateway AWS API gateway is only able to support HTTP(S) with an heavy focus on JSON. It is only able to support the Server-side discovery pattern, which is described in chapter 3. A typical application uses the AWS Elastic Load Balancing service to distribute load over a group of EC2 instances or ECS containers. However except for API composition The AWS API gateway is a great solution to implement the API gateway design. UAE Phone number quality lists


Another AWS service that provides API gateway-like functionality is the AWS Applica-tion Load Balancer, which is a load balancer for HTTP, HTTPS, WebSocket, and HTTP/2 ( When you configure your Application Load Balancer, you set routing rules to route requests to backend services that must run on AWS instances of EC2. UAE Phone number database

Similar to like the AWS API gateway like the API gateway, the AWS Application Load Balancer also meets certain requirements required for the API gateway. It provides basic routing capabilities. It’s hosted so it’s not your responsibility to install or operation. Unfortunately, it’s quite lim-ited. It doesn’t support HTTP route-based methods. Also, it doesn’t support API encryption or composition. Therefore, AWS Application Load Balancer doesn’t meet the requirements for API composition or authentication AWS Application Load Balancer does not fulfill the requirements of the API Gateway. UAE Phone number quality lists

Utilizing an API Gateway Product

Another option is to utilize an API gateway software like Kong and Traefik . These are open-source packages that you install and manage by yourself. Kong is built on the NGINX HTTP server, while Traefik was written using GoLang. Both of them allow you to configure flexible routing rules that utilize the HTTP method headers, path, and method to choose the backend service. Kong lets you set up plugins to implement features that are considered to be edge, such as authentication. Traefik is able to connect to some service registrations as described in chapter 3. UAE Phone number database

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While these tools provide edge functions and are able to handle capable routing capabilities however, they come with a few drawbacks. They must be installed, configured and run them by yourself. They do not allow API composition. If you’d like to use the API gateway to support API composition, you’ll need to create an API gateway. API gateway. buy UAE Phone number database

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Designing the API for your API

Making API gateways API gateway isn’t difficult at all. It’s basically a website application that redirects request to different services. You can create one with the framework of your choice. There are two major design problems you’ll have to tackle: buy UAE Phone number targeted list

Implementing a method for defining routing rules order to simplify code

Properly implementing properly the HTTP proxying behaviour, and the way HTTP headers are dealt with UAE Phone number quality lists

Therefore, a better start for creating the API gateway to utilize frames-work specifically designed for this use. Its built-in capabilities significantly reduce your code you have to write. UAE Phone number database

We’ll examine Netflix Zuul which is the open source initiative from Netflix and later, we’ll look at our thoughts on the Spring Cloud Gateway, an open source project by Pivotal.

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Netflix developed the Zuul framework to implement edge functions such as routing, rate limiting, and authentication ( Zuul frames-work is based on filters as reusable request interceptors which are similar to servlet filtering and NodeJS Express middleware. Zuul responds to the HTTP request by creating an array of filters which transform the request, call backend services, and then transform the response before sending it back to the user. Although it is possible to use Zuul directly however, making use of Spring Cloud Zuul, an open-source project by Pivotal it is much easier. Spring Cloud Zuul builds on Zuul and through convention-over-configuration makes developing a Zuul-based server remarkably easy.

Zuul handles edge and routing functions. It is possible to extend the functionality of Zuul by using Spring MVC controllers which use API composition. However, one of the major limitations for Zuul is the fact that it is able to only implement route-based routing. It’s for instance, it’s not capable of routing GET /orders to a particular service, and POSTing /orders to an alternative service. Therefore, Zuul doesn’t support the query design as described in Chapter 7. UAE Phone number quality lists


None of the solutions I’ve presented thus far can meet all needs. Actually I was about to give up looking in search of the perfect API gateway framework and begun to develop an API gateway that was based in Spring MVC. But then I discovered the Spring Cloud Gate-way project ( The project is an API gateway framework that is built upon various frameworks, such as Spring Framework 5, Spring Boot 2 as well as Spring Webflux, which is an open-source web framework that is an integral part of Spring Framework 5 and built on Project Reactor. Project Reactor is a reactive NIO framework that is compatible with the JVM that offers the Mono abstraction, which will be used later in this section. UAE Phone number database

The API gateway comprises three packages.

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ApiGatewayMain package defines the main program used by API gateway. API gateway.

One or more API packages — An API program implements an set API endpoints. For instance Orders is one of them. Orders packages implements API endpoints related to Orders.

Proxy package consists of proxy classes utilized by the API packages to call the services.
The OrderConfiguration class specifies the Spring beans that are responsible for routing orders-related requests. A routing rule may match against any mixture of HTTP method, headers and the route. The orderProxyRoutes @Bean identifies rules that match API operations to the backend URLs for services. For instance, it routes paths that begin with /orders towards the Order Service. UAE Phone number quality lists

The orderHandlers @Bean specifies rules that are overridden by the order-ProxyRoutes rules. These rules translate API actions to handling methods that

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constitute an equivalent of the Spring WebFlux equivalent of Spring MVC controller methods. For example, order-Handlers maps the operation GET /orders/ to the OrderHandlers::get-OrderDetails() method. purchase UAE Phone number lists

The OrderHandlers class implements various request handler methods, such as OrderHandlers::getOrderDetails(). This method makes use of API composition to get the details of an order (described previously). The handle methods call backend services by using proxy classes that are remote like OrderService. This class specifies methods to invoke the OrderService. UAE Phone number database
Let’s look at the code, beginning at the order configuration class.


The class OrderConfiguration, which is shown in Listing 8.2 is an @Configuration class in Spring. The class defines Spring @Beans that implement the endpoints for /orders. The orderHandlerRouting and orderProxyRouting @Beans make use of to use the Spring WebFlux routing DSL to determine the routing for the request. The orderHandlers@Bean implements request handlers which carry out API composition. buy UAE Phone number database

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The OrderHandlers class, as shown in the following table is the one that defines the methods used by request handlers to provide custom behavior, such as API composition. GetOrder-Details() method is an example. It performs API composition to get details about an order. This class is embedded with various proxy classes which make calls to the backend service. UAE Phone number database
The OrderHandlers class implements custom request handling algorithm. purchase UAE Phone number lists

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public-class OrderHandlers {public class OrderHandlers

private OrderService orderService; private KitchenService kitchenService; private DeliveryService deliveryService; private AccountingService accountingService; public OrderHandlers(OrderService orderService, KitchenService kitchenService, DeliveryService deliveryService, AccountingService accountingService

GetOrderDetails() method makes use of API composition to retrieve the details of an order. The code is written in a scalableand responsive style that utilizes the Mono abstraction that is offered via Project Reactor. The term Mono that is a more sophisticated version of Java 8 CompletableFuture is the result of an asynchronous procedure which is either a result as well as an error. It provides a powerful API to transform and combine the values generated by the asynchronous operation. You can utilize Monos to write code that is concurrent in a way that’s easy and simple to comprehend. In this instance it’s you can use the getOrderDetails() procedure calls the four services in parallel , and blends the results into An Order-Details object.

This getOrderDetails() method uses an ServerRequest, which refers to Spring’s Web- purchase UAE Phone number lists

The Flux represents an HTTP request as an element, and performs what follows:

It takes the orderId from the path.

It calls the four services asynchronously through their proxy servers that result in Monos. To increase the accessibility the getOrderDetails() examines the results of all the services, with the exception of those of the OrderService to be optional. If the Mono result returned from an optional services includes an exception then the method called onErrorReturn() changes it to an Mono that contains the empty Optional. UAE Phone number database

It is able to combine the results asynchronously by using Mono.when() and results in the result as a Mono The four values are contained in the formula.

The Mono is transformed. Mono into a Mono by calling Order-Details::makeOrderDetails.

It converts the OrderDetails into an ServerResponse that corresponds to an actual Spring WebFlux representation of the JSON/HTTP response.

It is evident as getOrderDetails() utilizes Monos and Monos, it simultaneously invokes the services and blends the results without having to use messy, difficult-to-read callbacks. Let’s look at one of the proxies for service which return the results of an API call wrapped within a Mono.


This class is as shown in the next listing is a remote proxy of the Order Service. It connects to the Order Service using a WebClient that can be described as the Web-Flux Spring responsive HTTP client. UAE Phone number database

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FindOrder() method will retrieve the OrderInfo of an order. It utilizes WebClient to send the HTTP requests towards the Order Service and deserializes the JSON response into an OrderInfo. WebClient provides an API that is reactive, which wraps the result in Mono. FindOrder() method makes use of flatMap() to convert the Mono into a Mono . Like the name implies, this bodyToMono() method returns the body response in the form of a Mono. purchase UAE Phone number lists


The ApiGatewayApplication class, shown in the following listing, implements the API gateway’s main() method. It’s a common Spring Boot primary class. UAE Phone number database

Spring Cloud Gateway is an excellent tool for creating the concept of an API gateway. It allows you to set up basi