As described in the title, I have a class which implements the Queueable interface, for each item it sends an request and I would like to get the response back and use it. Syntax: public class CLASS_NAME implements Queueable {} We cannot monitor the jobs. startTest and Test. Schedulable Interface. 非同期 Apex プロセスを制御するには、 Queueable インターフェースを使用します。. To counter this, I created an Apex Queuable job which does the job of writing the contents into a file. The static resource contains the response body to return. Automated testing of chained Queueable jobs in Salesforce. Queueable Apex is a great new tool but there are a few things to watch out for: The execution of a queued job counts once against the shared limit for asynchronous Apex method. 5. stopTest, you can assert that indeed target record (s) have been modified/created/deleted. stopTest block. Apex is great for building out complex automations that would be difficult or impossible to do with declarative automations such as Flows or Process Builders. 2 100. 3. This limit is for your entire org and is shared with all asynchronous Apex: Batch Apex, Queueable Apex, scheduled Apex, and future methods. For @futures and Queueable there is no concurrent limit, for Batch jobs there can be 100 queued Batch jobs in the flex queue. Each queued job runs when system. Here is the class structure at a high level: Public Parent Class Implements Queuable { public class Child1 Implements Queuable {public void execute (queuableContext con)//do stuff System. My question is: Is there an advantage or difference in putting logic in the Constructor vs the Execute Method? In the following queueable class I am selecting one of the two templates and performing a callout for each of the lead records passed in from the trigger. a Queueable can be called from a Batchable. My current workaround: 使用方法. startTest and Test. stopTest block. Using this way, you can create the chaining between the batches. Apex methods with the future annotation that haven’t yet been executed. Couple things. Database. Apex, future methods, Queueable Apex, and scheduled Apex) per a 24-hour period1,6 org multiplied by 200, whichever is greater Number of synchronous concurrent transactions for long-running transactions 10 that last longer than 5 seconds for each org. This interface is a cool new way to execute asynchronous computations on the Force. sfdc_to_learn sfdc_to_learn. @AdrianLarson When chaining jobs, you can add only one job from an executing job with System. When using queueable jobs it will make the AsyncApexJob which we can monitor like Scheduled jobs. The ID of a queueable Apex job isn’t returned in test context—System. Unlike future method, queueable has only execute. Flows typically take longer to edit than code, do not run efficiently, and may cause problems on bulk updates. March 9, 2016. Step 3 – Click on New to select a new Apex Class. execute (null); Queueable q2 = new MySecondQueueable (q1); q2. So atmost 100 jobs can be added in one go. S. Batchable trailhead challenge which does not apply to this challenge. Using asynchronous automations is increasingly important as the. For example, a developer could build an archiving solution that runs. Queueable インターフェースを実装するには、最初に implements キーワードでクラスを次のように宣言する必要があり. List<AsyncApexJob> batchJobs = [ SELECT ApexClassId FROM AsyncApexJob WHERE JobType = 'BatchApex' AND Status = 'Processing' // OR Status = 'Queued'ADD ANY OTHER CONDITION THAT YOU WANT ]; Using above piece of code you can check. たとえば、最大 5,000 万件のレコードをクリーンアップ. . This solution is for Asynchronous Apex. It gives a Job ID and lets us store complex data patterns. enqueueJob in a single transaction. stopTest() Each test method is allowed to call this method only once. abortJob with an AsyncApexJob ID. Queueable Class: callout1 ; processData ; Again enqueue- newEnqueueClass ; newEnqueueClass : Insert data; future callout [since we cannot have callout after DML]. Join us to learn how to use queueable Apex to build robust asynchronous. For one thing, the queueable execute() method is an instance method, not a static method. But that is a chain and not a queue. This article covers the best way to execute performant HTTP-related code, while allowing for further processing to be done. Join us to learn how to use queueable Apex to build robust asynchronous. Here's what we get back: 15:42:44:004 USER_DEBUG [9]|DEBUG|Account Name. "A single Apex transaction can make a maximum of 100 callouts to an HTTP request or an API call. I have a Queueable job en queued by a custom trigger and the Queueable job makes REST API call to an external system. I have a chained queuable apex class making an HTTP request to an external server. Take control of your asynchronous Apex processes by using the Queueable interface. Dan Appleman solution to call batch job from finish method of another batch job. An Apex trigger can receive a batch of events at once. Queuable Advantage: Queueable can run parallelly and there no limit for chaining. The first iteration passed unit and functional testing, but was found to cause Apex CPU. AllowsCallouts { public void execute. The main differences between @future methods and Queueable Apex jobs are: When you enqueue a new job, you get a job ID that you can actually monitor, like batch jobs or scheduled jobs! You can enqueue a queueable job inside a queueable job (no more “Future method cannot be called from a future or batch method” exceptions). Set up Apex Replay Debugger for debugging more complicated issues such as Queuable Apex or Apex trigger issues in your org:In queueable, which seems to be the silver knight I have wanted but, I'm having a misunderstanding as to how to go about this (most examples I find show the queuable apex class which I understand but, not understanding how. 1. The maximum batch size in a platform event trigger is 2,000 event messages. In this example, we use static resources and a mock interface later on. let’s say there are N jobs, A, B, C and so on. This is also true for Scheduled jobs, Batchable jobs, future methods, sending emails, calculating sharing rows, and almost any other type of asynchronous code or action that may exist in the future. I did went through multiple Q&A posted in the community but still stuck with it. Each queued job runs. Too many queueable jobs added to the queue: 2. from your Queueable. The above verifies that your triggerhandler schedules a queueable but does not execute it because there is no stopTest (). By creating and pushing Salesforce Batch Jobs in Apex Flex Queue, you can submit up to hundreds of jobs in a single queue. Test Queueable Used:Queueable apex provides us a means to create an asynchronous job (An asynchronous job means a piece of work, which is scheduled to run in background, for e. Being able to react to uncatchable Apex errors without having to spend an additional 10% of your net Salesforce cost to become an Event Monitoring customer alone would make this worth it. Queueable Interface methods and Future methods are Asynchronous Apex Processes that add jobs to the job queue and each job runs when system resources become available, so it doesn’t delay the execution of the main Apex logic. The following code sample shows how to test the execution of a queueable job in a test method. Being able to react to uncatchable Apex errors without having to spend an additional 10% of your net Salesforce cost to become an Event Monitoring customer alone would make this worth it. Is there a native and reliable way in Apex to check whether the Platform Event I am about to publish falls within this limit?Step 4: Holding Salesforce Batch Jobs in Apex Flex Queue. You need the List<String> to be an instance property, not a static one. Queuable Apex - chaining jobs vs calling other classes synchronously. I am attempting to create logic that, on Contact record insert or update, will compare the Phone value of the record to another reference object and conditionally populate a checkbox as a result of the comparison. However, once the flex queue is full every attempt to execute another batch will bomb out with a limits violation. It allows you to submit jobs for asynchronous processing with some additional benefits comparing to @future methods. Improve this question. To test future methods, enclose your test code between the startTest () and stopTest () test methods. After each request comes back with a successful response, the next class will fire and make another request to a. So my question as I am enqueuing only one class. This interface enables the way of running your asynchronous jobs or code of job in comparison to the future method. Hi @novumcoder. If you need to process a high volume of jobs, this limitation can be problematic, as it hard caps you at <6k jobs/day on a single chain. 1. That method causes a record to be inserted into the AsyncApexJob object (that's what the jobId you get back from System. set Util. I had to enable the setting that allowed me to upload an apex class while it has future processes schedule, but after the new class was uploaded and. LimitException: Too many SOQL queries: 101". December 13, 2020 · Like; 0 · Dislike; 0; james william 16. このインターフェースにより、ジョブをキューに追加して監視できます。. . As a good dev I went to the docs to solve this problem. Jun 16, 2021 at 13:55. No limit is enforced on the depth of chained jobs, which means that you can chain one job to another job and repeat this process. While in a batch there is a limit of 100 batches; Queueable can be much faster than batch apex if used properly; This can be invoked from future method as well; Batch Advantage: Batch allows to query up to 50 million records in a start method (This is unique)I have a chained queuable apex class making an HTTP request to an external server. Remember this is a shared limit for all batches on your org. Queueable Apex is useful when you need to perform a series of operations that depend on each other. Jun 16, 2021 at 13:55. How should this issue be solved? Any ideas, highly appreciated. 3. Queueable is a hybrid between the limited future methods and the resource-hungry Batchable interface. Couple things. I find this contradictory that you can add up to 50 jobs in one transaction, but you can't start one job from. Originally what I wanted to do was have trigger call a method on the queueable which would update a list of records to update and enqueue a job if one wasn't already enqueued. com platform, given you already know @future, Scheduled Apex Jobs, and Batch Jobs. public class OrderItemFilePostHelper implements System. Need help with Apex Batch job. Among these are complex asynchronous automations including Queueable, Batch, and Schedulable Apex. Here is the class: global class NSStatusOrderCronSC implements Schedulable { global void execute (SchedulableContext sc) { String norder; String IdOpp; List<Opportunity> opList =. This will enable you to add jobs to queue and monitor them. The Apex Batch Job, at the top of its execute () method, sets the variable to true. This works perfectly during our testing. 0. For example, a developer could build an archiving solution that runs. getLimitQueueableJobs () method returns the expected value of 1. isEnqueueable = false; DML the record in the testmethod. 6) No more than 50 method calls per Apex invocation. Apex offers multiple ways for running your Apex code asynchronously. If you can add the complete class of Queueable interface, I can check further if still facing issues. BatchClass (Runs every hour) (Generates a map with "N" records for every batch context, and passes it to Future method in an apex class) ===> 3. @sfdcfox- Thank you for the recommendation, Now with Queuable implementation all the dependency errors are gone. You can use Salesforce Batch apex or a Queuable to split the transactions into at least 4-5 transactions with 40-50 queries each. Finalizer interface, it enables us to attach actions to asynchronous Apex jobs using the Queueable framework. This is expected behavior if you carefully read the documentation on how Test. Parallel callouts in apex. Each Queueable job enqueued and executed represents a separate transaction, which is the unit of limits consumption. In the Integration Procedure, under Procedure Configuration, he expands the. // Create event Event_Name__e event = new Event_Name__e(); // Set. This helps us avoid hitting governor limits while sending the messages by splitting it over multiple executions (the queueable chains itself as needed). Apex, future methods, Queueable Apex, and scheduled Apex) per a 24-hour period1,6 org multiplied by 200, whichever is greater Number of synchronous concurrent transactions for long-running transactions 10 that last longer than 5 seconds for each org. Create a Queueable Apex class that inserts the same. " Is anyone aware if that limit is higher in a future methods or queueable apex? Generally, limits are relaxed in an asynchronous context with apex, but I can't find anything talking about callout limits specifically. Syntax: @future. That limit is 50, or 1 if the current execution is already happening within a Queuable. You should do this minimally, of course, but as often as necessary. I observe the followingSo I tried again by doing it in the queueable apex class. 1 Answer. Thus the callout issues are omitted. Improve this question. A class and method that can be added to the queue to be executed Queueable Class is monitorable and abortable. Interestingly, while Batchable-> Batchable isn't supported, Batchable-> Queueable-> Batchable is, so the Queueable insulates the pair of. Generic Approach to Salesforce Queueable. And what if the count returned is more then 150, is there any way to abort the list of jobs in one go preventing 150 DML exception – ScoRpion. 6. public class SampleQueueble implements Queueable { public final List<String> data; public SampleQueueble (List<String> input) { data = input; } public void. You're not receiving. What is happening here appears to be your process automation downstream. Asynchronous Apex. Take control of your asynchronous Apex processes by using the Queueable interface. Uses a Publish / Subscribe model to decouple code. Usage. The order of events is based on the event replay ID. Those objects can be accessed when the job executes. public class TerritoryAssignmentClass implements Database. Above code will not work when Event is being created from a queueable itself. enqueueJob ()). Interestingly, while Batchable-> Batchable isn't supported, Batchable-> Queueable-> Batchable is, so the Queueable insulates the pair of. Queueable apex can be called from the Future and Batch class. Unlock the power of both Batchable and Queueable Apex with the easily extendable DataProcessor pattern, which I’ll detail in this post. Chaining jobs. Unlike future methods, they can have non-primitive data types such as sObjects and custom Apex Types to be passed. Call System. Queuable Advantage: Queueable can run parallelly and there no limit for chaining. global class AddPrimaryContact implements Queueable { private Contact queueContact; private String contactState; public AddPrimaryContact(){} public AddPrimaryContact(Contact con, String state){ queueContact = con; contactState = state; }Invocable Class can't run call to API method. Apex syntax looks like Java and acts like database stored procedures. Considerations for Batch Apex . Step 2 – On the Quick Find tab, search Apex Classes. Recommend using Queuable Apex instead because one can provide more complex input to it and have better visibility via Apex Jobs in Setup. Share. Once you surpass a chain depth of 4, Salesforce will slow you down to 15 seconds between executions. I'm coding an execute() method for the new "queueable" interface. It's important to note that the Queueable (or future, or batch) doesn't start executing until this transaction, the Anonymous Apex we're running, commits successfully and without a rollback. It could be useful for doing post-Right now if I call the action button without Queueable Apex, from all the parameters I get from the Visualforce page and then perform action on the backend, due to the Apex Triggers I always will get "Error: System. 3. 821 1 7 24. public with sharing class queueableClassTest { static wrapperClass WC; @TestSetup static void makeData () { WC = testDataFactory. Queueable Apex allows you to submit jobs for asynchronous processing similar to future methods with the following additional benefits: Non-primitive types: Your Queueable class can contain member variables of non-primitive data types, such as sObjects or custom Apex types. An Apex trigger processes platform event notifications sequentially in the order they’re received. Nick Nick. Queueable is a completely different framework from future methods, and it gives a lot of benefits over it. Take control of your asynchronous Apex processes by using the Queueable interface. I am implementing Queueable class to return data to the callout as below:The difference between queueable and Batch Apex (which all belong to asynchronous Apex), is that you would use Batch Apex whenever you are processing a larger number of records compared to queueable. cont = cont; } P. class and method implementation must be declared as public or global. Some years ago, thinking about asynchronous processing in Salesforce was sort of painful. Queueable Apex is similar to Future Methods with an extra set of features and capabilities. 69. AsyncException: Database. Earlier I wrote a blog post dedicated to Asynchronous processing in Salesforce. The Queueable interface is there for you to enjoy. Such jobs are listed as Future in the Job Type column, and don’t have values in the Total Batches or Batches Processed columns. 501; asked Nov 27, 2019 at 16:11. let’s say there are N jobs, A, B, C and so on. I found out that the batch update is triggering triggers on the user and one such trigger is using enqueue method. The syntax for a constructor is similar to a method, but it differs from a. 1. In Developer Edition orgs, the limit is 5. Getting Id of your Job:- ID JobId =system. Please find below answers : considering that in every transaction you are up to 100 callouts, it means that every new job I create its a new transaction itself?2 Batch Apex is typically the best type of asynchronous processing when you want to: A Make a callout to a web service when a user updates a record. All asynchronous calls made after the startTest. And @future requires that the method be static. You've put together several things here that don't necessarily go together, before we even look at the code. I recive the error: Too many queueable jobs added to the queue. It is useful when you need to perform operations at a specific time, such as sending an email or updating a record. Create a constructor for the class that accepts as its first. First, to check if the process is done, you can use a simple apex:actionPoller that calls an Apex method every five seconds to query the AsyncApexJob object to check the status. You can create response in such a way that the data is affected in an expected way. This queueable job is queued up using Apex. It required a long time to process and was often used only to handle callouts or things that were slightly longer than a normal transaction could handle. Benefits : Queueable apex supports non-primitives like SObject and custom Apex types. abortJob with the parent CronTrigger ID. These asynchronous apex can be used in. Usage. 1 Answer. Are queuable jobs given precendence over batch jobs. Queueable Apex is a more advanced and enhanced version of the future method with a few added features which are mentioned below. Batch Apex . Interviewer: How Chaining works in Queueable Apex? Interviewee: Chaining allows us to customize the execution order of a set of jobs in a process. The maximum number of asynchronous Apex method executions (batch Apex, future methods, Queueable Apex, and scheduled Apex) per a 24-hour period: 250,000 or the number of user licenses in your org multiplied by 200, whichever is greater You will have to balance it all out. Dave Humm. Batch Apex Chaining :If you need to run a job after some other processing is done first by another job, you can chain queueable jobs. I need something where I get the job ids upfront when I enqueue my jobs so I can later monitor. Process Builder -> Invokable Apex -> Chain of Queueable Apex Callouts. Write unit tests that achieve 100% code coverage for the class. However Queueable is asynchronous which leads me to question sending a UoW into the Queueable class. Write unit tests that achieve 100% code coverage for the class. enqueueJob () call (s) from your for loop in the batch class. g. CSS ErrorQueueable Apex Limits. In Developer Edition orgs, the limit is 5. Among these are complex asynchronous automations including Queueable, Batch, and Schedulable Apex. Those objects can be accessed when the job executes. Future method cannot be called from a future or batch method. I am invoking this job from the finish method. This way, the callout runs on a separate thread. B Schedule a task to run on a weekly basis. governorlimits. Basically, it has nice tools to execute the async job but it requires an. As I understand all the code samples out there, the next job is enqueued after the work of the previous one is done. I want to run the execute method of a Queueable Apex class. It has all the functionalities of the future method along with the power of Batch Apex. . In a real-life scenario, a queueable class will make a callout, get response and update/create/delete a record. For long-running jobs with large data volumes that need to be performed in batches, such as database maintenance jobs. Under the section of "Queueable Apex Limits", second bullet point says - You can add up to 50 jobs to the queue with System. (If there are a lot of Account records being updated then moving this task to async might be a good idea). Allow queueable jobs to have a configurable delay. 2 Answers. public class Queueabletest implements Queueable { private String v1; private Integer v2; // Constructor executes now public. Queueable Apex is a great new tool but there are a few things to watch out for: The execution of a queued job counts once against the shared limit for asynchronous Apex. Email this to. Setting of a parent ID is an example of a task that can be done asynchronously. Sorted by: 8. Queueable apex still executes in test context even if Enqueue Job is not called between Test. enqueueJob () points to), and thus you find yourself in the "pending work, commit or roll back" situation. 1. abortJob) and schedule a new job 20 minutes out. I had to enable the setting that allowed me to upload an apex class while it has future processes schedule, but after the new class was uploaded and. Represents the parameter type of the execute () method in a class that implements the Queueable interface and contains the job ID. Queuable apex basics. Yes, you can call (A queueable class method acts as a future method) only from the Batch class finish method. In Queueable apex, we can chain up to 50 jobs and in developer edition, we can chain up to 5 jobs only whereas in BatchApex 5 concurrent jobs are allowed to run at a time. Testing future methods is a little different than typical Apex testing. enqueueJob returns null in a running test. enqueueJob method, the method returns the ID of the AsyncApexJob record which can be used to identify and. For example, we use a queueable with a list of a custom apex class where that class holds a single outgoing message's information (email template to use, ID(s) of the recipient(s) for the message). You can add only one job from an executing job, which means that only one child job can exist for each parent job. 31 6 6 bronze badges. . edited Feb 1, 2022 at 19:59. 使用される最大の理由は、大量のレコードを処理する必要があるからです。. What is Queueable Apex? Queueable Apex, as a feature in Salesforce, introduces a more robust and flexible way to run asynchronous Apex code. The key difference can be found in the Queueable Apex documentation: Similar to future jobs, queueable jobs don’t process batches, and so the number of processed batches and the number of total batches are always zero. Flows are really only meant for simple logic. Implementing A Timeout / Delay In Apex. The class which implements the Queueable interface are basically called as Queueable apex class. Queueable has some benefits over using @future, the other aysnc "immediate" execution path, but neither has the delay you are looking for. That data is automatically available when the execute method is invoked some time later. I cannot make you use it; I can only tell you why you should and give you incentive to do so. Basically, it is. Apex offers multiple ways for running your Apex code asynchronously. Even if two transactions. Queueable Apex is a more advanced and enhanced version of the future method with a few added features which are mentioned below. enqueueJob(queueable, delay) Adds a job to the Apex job queue that corresponds to the specified queueable class and returns the job ID. As Dan Appleman notes in the latest edition of Advanced Apex, a Queueable can call a Future method, and a Future method can. The system collects all asynchronous calls made after the startTest (). The maximum number of asynchronous Apex method executions (batch Apex, future methods, Queueable Apex, and scheduled Apex) per a 24-hour period 1, 6 250,000 or the number of user licenses in your org multiplied by 200, whichever is greaterQueueable Apex can be used to run processes that will take a long time, such as extensive database operations or external web service callouts. 1 For Batch Apex, method executions include executions of the start, execute, and finish methods. So I am looking to implement Queueable jobs in apex to send 200 emails (1 job) every 30 minutes until all the jobs are done, I am struggling to find any documentation on how this functionality can be added so I figured I would ask the community, if anyone has ever implemented time delays between Queueable jobs. System. The Apex flex queue has the maximum number of 100 jobs, Database. You can use Salesforce Batch apex or a Queuable to split the transactions into at least 4-5 transactions with 40-50 queries each. Again, when using a mock callout, the request isn’t sent to the endpoint. Your logic is slightly flawed. every transaction boundary (specific to the apex jobs or future calls inside test class). Any code that executes after the stopTest method is assigned the original limits that were in effect before startTest was called. Create a Queueable Apex class that inserts Contacts for Accounts. It was probably easier and safer for salesforce to create a new framework/interface, than the modify the existing @future implementation without breaking existing apex code. So make sure you adjust your code accordingly (either to separate into different jobs or do all callouts and then make db changes) [2] Scheduled job can start 20 other queueable jobs and one queueable job can start one other queueable job. Schedulable Interface is. Future method cannot be called from a future or batch method. You can add up to 50 jobs to the queue with System. Public versus private -. enqueueJob (qe); 2. 1. emails list is empty by default, which may be sufficient for synchronous work. If you need to process a high volume of jobs, this limitation can be problematic, as it hard caps you at <6k jobs/day on a single chain. new. I would also move the instantiation to reside solely in the constructor. Sorted by: 1. The issue with starting a batch job in the finish method is that the batch apex class I am using is dynamic and is used by so many different schedulabe interfaces across my org. enqueueJob in a single transaction. I have a chained queuable apex class making an HTTP request to an external server. Apex Code Development (90767) General Development (55147) Visualforce Development (37252) Lightning (18263) APIs and Integration (17147). However, there are limits on how many Queueable you can queue from a single thread. ","In the test class, insert 50 Account records for BillingState "NY" and 50 Account records for BillingState "CA". The transaction is asynchronous of course but its one transaction. After each request comes back with a successful response, the next class will fire and make another request to a different endpoint on the same server. Queuable Apex - chaining jobs vs calling other classes synchronously. QUEUEABLE APEX. stopTest, you can assert that indeed target record (s) have been modified/created/deleted. An Apex trigger processes platform event notifications sequentially in the order they’re received. An Apex transaction is sometimes referred to as an execution context. Let’s say you want to process 1. 1 つのトランザクションで System. Follow edited Dec 6, 2022 at 16:22. Description. Batchable and Queueable Apex are both powerful processing frameworks within Salesforce. Each queueable job gets its own set of governor limits. startTest() and Test. I currently have in place a class which is scheduled to run nightly, the execute() of which looks like (some names changed to protect the innocent) Queueable Apex Simplified. Use Case: Pre-requisite: Create a permission set with API name Sales_User_Permissions. This limitation has been removed now. Those objects can be accessed when the job executes. We did a clean up exercise to consolidate all the logic in one queueable class. In contrast, the Limits. I was able to make a callout to external service inside the Queuable Apex class The challenge is to schedule a job that will call the Queueable apex class: AsyncExecutionExample? Any pointers will help. The maximum number of asynchronous Apex method executions (batch Apex, future methods, Queueable Apex, and scheduled Apex) per a 24-hour period 1, 6 250,000 or the number of user licenses in your org multiplied by 200, whichever is greater Queueable Apex can be used to run processes that will take a long time, such as extensive database operations or external web service callouts. Then after Test. So - Queueable Apex = Future Method + Batch ApexIt. Using Constructors. Governor Limits in Salesforce for the total number of callouts (HTTP requests or web services calls) per transaction. AllowsCallouts to. To use batch Apex, write an Apex class that implements the Salesforce-provided interface Database. Before Transaction Finalizers, you had to query AsyncApexJob ’s ID via SOQL and implement a retry logic in Queueable Apex. I would also move the instantiation to reside solely in the constructor. Moreover Queueable apex supports getContent/getContentAsPDF () method. So make sure you adjust your code accordingly (either to separate into different jobs or do all callouts and then make db changes) [2] Scheduled job can start 20 other queueable jobs and one queueable job can start one other. 1. ) PS. Why we can’t pass sObject in future methods? 39. stopTest() works. // call this method when voucher type is PDF public static void createGiftCardPDF (ResponseWrapperData. You can add only one job from an executing job, which means that only one child job can exist for each parent job. This means it can handle more complex transactions and larger volumes of data.