Please look at the following snippet: https://github.com/viewflow/viewflow/blob/fa48ec8b129171bceaa25c3ef4a7e6385c30ff6f/viewflow/activation.py#L364
I don't understand why ViewActivation.prepare does not invoke self.task.save() after self.task.started = now().
It seems that self.task.save() is invoked in other activations after self.task.started is set.
Is this a feature or a bug?
Background: I am currently building an analytics tool on top of viewflow for understanding the output performance of my team. I am trying to find out how long my users are spending per task by calculating task.finished - task.started.
Viewflow flow build from tasks, each task type is a separate finite state machine with own set of transitions. There is no restriction on what should happen inside a task activation transition. Task could be saved or not, depends on what logic desired at this place.
.prepare calls do not save the task b/c they happen on "HTTP GET" requests, that should be idempotent.
task.started tracked over the GET/POST activation.prepare/activation.done as a hidden form data from {{ activation.management_form }}
Extending task model and corresponding management_form would allow you to track any additional task execution information.
Related
I have two processes I want to juxtapose. The first is a Manual workflow that is well represented by the Process library. The second is a software System that performs the same work, but is better modelled as a state transition system (e.g. s/w component level).
Now in AnyLogic, state models are for agents, that can run through processes with animations (counts), or move across space. What if I want to use a state chart to run an agent through? so I have a System state chart/agent and a Job state chart/agent?
I want Jobs from Population A to go through the Manual process flow chart and Jobs from Population B to go through the System state flow chart, so I can juxtapose the processing costs. I then calculate various delays and resource allocations for each of the Jobs going through and compare them.
Can anyone explain how to setup a state chart as the base process, another agent will go through? Is this even possible?
Please help
Thanks
This will not work as you would like it to, for these reasons:
You can't send an Agent into a flowchart. (Not sure how AnyLogic is handling it internally, maybe a generic token, or no flow at all, just changes to the state).
In AnyLogic there can only be one state active (simple or combined state) per state chart, so you can't represent a population with several members.
Agents can't be in more then one flow at a time, so even if it would be possible to insert an Agent into a statechart, this limitation would also apply.
The conclusion of this is: State charts are suitable for modeling individual behaviour (inside one Agent), whereas process flows can be both used for individual behaviour (inside one Agent, running a dummy Agent through) as well as for groups (multiple Agents running through process).
The normal use case would be to add the state chart to the Agent type running through your process flow (as you already noted in your question), applying the changes caused by the state chart to the individual agent.
I am creating an activity diagram
Admin log in to the web
If validated, it reaches the dashboard
Through dashboard it can manage account, manage product and manages issues
after performing one of above options, it can go back to dashboard or logout from system.
I have used fork/join, is it correct or I should be using decision/merge instead
2ndly, is the procedure of logging out or performing another option available in dashboard correctly defined?
Your activity is having several issues.
First and most severe, it will not do anything because actions (and mostly those - not all model elements in activities) having an "implicit and sematics" for incomming control flows. This means that an action is only executed when an token is offered on ALL incomming control flow actions, otherwise it waits. So as your control flow from validate can not offer an token before Login has been executed and finished, you are having a lock. And nothing is executed. The same applies to Dashboard. To solve this you need to model merge nodes.
The second point is that you only want to execute (according to your description) one of the manage actions. (Btw. names with generic verbs like "manage", "maintain", "do", "perform", etc. are quite bad names for actions, use more specific ones instead). Your model executes, irregardless of the selection in the dashboard action, all manage actions concurrently. Concurrently means in an arbitrary order and does not demand a parallel execution. Thus you should replace the fork with a decision node, where the conditions on the outgoing flows are based on the selection from the dashboard. An decision node can have an arbitrary (but finite) number of outgoing control flows. All the outgoing control flows from the manage actions are merged using a merge node instead of a join node. As the join node would wait for an incommingtoken per incomming control flow.
A minor point, that would be solved when using an UML/SysML tool is that the fork and join nodes are bars and not rectangular frames.
Your AD has 2 flaws. First a fork/join is a solid thick line, but not a hollow rectangle. Second, it's used wrongly. This way you run all Manage actions in parallel and continue when they are all finished. According to your description use a diamond to decide for one of the actions Also use the diamond afterwards to merge the flows and continue to Logout.
I'm trying to apply BDD practices to my organization. I work in a bank where the nightly batch job is a huge orchestration multi-system flow of batch jobs running and passing data between one another.
During our tests, interactive online tests probably make up only 40-50% of test scenarios while the rest are embedded inside the batch job. As an example, the test scenario may be:
Given that my savings account has a balance of $100 as of 10PM
When the nightly batch is run at 11PM
Then at 3AM after the batch run is finished, I should come back and see that I have an additional accrued interest of $0.001.
And the general ledger of the bank should have an additional entry for accrued interest of $0.001.
So as you can see, this is an extremely asynchronous scenario. If I were to use Cucumber to trigger it, I can probably create a step definition to insert the $100 balance into the account by 10PM, but it will not be realistic to use Cucumber to trigger the batch to be run at 11PM as batch jobs are usually executed by operators using their own scheduling tools such as Control-M. And having Cucumber then wait and listen a few hours before verifying the accrued interest, I'm not sure if I'll run into a timeout or not.
This is just one scenario. Batch runs are very expensive for the bank and we always tack on as many scenarios as possible to ride on a single batch run. We also have aging scenarios where we need to run 6 months of batch just to check whether the final interest at the end of a fixed deposit term is correct or not (I definitely cannot make Cucumber wait and listen for that long, can I?)
My question is, is there any example where BDD practices were applied to large batch scenarios such as these? How would one approach this?
Edit to explain why I am not targeting to execute isolated test scenarios where I am in control:
We do isolated scenarios in one of the test levels (we call it Systems Test in my bank) and BDD indeed does work in that context. But eventually, we need to hit a test level that has an entire end-to-end environment, typically in SIT. In this environment, it is a criteria for multiple test scenarios to be run in parallel, none of which have complete control over the environment. Depending on the scope of the project, this environment may run up to 200 applications. So customer channels such as Internet Banking will run transactional scenarios, whiles at the core banking system, scenarios such as interest calculation, automatic transfers etc will be executed. There will also be accounting scenarios where a general ledger system consolidates and balances all the accounts in the environment. To do manual testing in this environment frequently requires at least 30-50 personnel executing transactions and checking on results.
What I am trying to do is to find a way to leverage on a BDD framework to automate test execution and capture the results so that we do not have to manually track them all in the environment.
It sounds to me as if you are not in control over the execution of the scenario.
It is obviously so that waiting for a couple of hours before validating a result is a not a great idea.
Is it possible to extract just the part of the batch that is interesting in this scenario? If that is possible, then I would not expect the execution time to 4 - 6 hours.
If it isn't possible to execute the desired functionality in isolation, then you have a problem regarding test-ability of your system. This is very common and something you really want to address. If the only way to test is to run the entire system, then you are not able to confidently say that it is working properly since all combinations that need testing are hard, sometimes even impossible, to execute.
Unfortunately, there doesn't seem to exist a quick fix. You need to be in a position where you are able to verify small parts of the system in order to verify them fast and reliably. And it doesn't matter if you are using Cucumber or any other tool to for the verification, all tools will have the same issue.
One approach you might consider would be to have a reporting process that queries the results of each batch run. It would then store the results you were interested in (i.e. those from your tests) in to a test analysis database.
I'm assuming that each batch run has a unique identifier. This identifier would be used as the key for the test results.
Here is an example of how it might work:
We know when the batch runs are finished (say this is at 4am). We schedule a reporting job to start after batch run completion (say at 5am) that analyses the test accounts.
The reporting job looks at Account X and Account Y. It records the amount of money in their account in a table alongside the unique identifier for the batch run. This information is stored in a test results database.
A separate process matches up test scenarios with test results. It knows test scenario 29 was tied to batch run ZZ20 and so goes looking in the test results database for the analysis from batch run ZZ20.
In the morning the test engineer checks the results of the run. They see that test scenario 29 failed as there was only £100 in Account X rather than the £100.001 that was expected.
This setup would allow you to synchronously process asynchronous batch runs. It would be challenging to configure though, as you would need to do a lot of automation around reporting and linking test scenarios with test results.
Greetings SO denizens!
I'm trying to architect an overhaul of an existing NodeJS application that has outgrown its original design. The solutions I'm working towards are well beyond my experience.
The system has ~50 unique async tasks defined as various finite state machines which it knows how to perform. Each task has a required set of parameters to begin execution which may be supplied by interactive prompts, a database or from the results of a previously completed async task.
I have a UI where the user may define a directed graph ("the flow"), specifying which tasks they want to run and the order they want to execute them in with additional properties associated with both the vertices and edges such as extra conditionals to evaluate before calling a child task(s). This information is stored in a third normal form PostgreSQL database as a "parent + child + property value" configuration which seems to work fairly well.
Because of the sheer number of permutations, conditionals and absurd number of possible points of failure I'm leaning towards expressing "the flow" as a state machine. I merely have just enough knowledge of graph theory and state machines to implement them but practically zero background.
I think what I'm trying to accomplish is at the flow run time after user input for the root services have been received, is somehow compile the database representation of the graph + properties into a state machine of some variety.
To further complicate the matter in the near future I would like to be able to "pause" a flow, save its state to memory, load it on another worker some time in the future and resume execution.
I think I'm close to a viable solution but if one of you kind souls would take mercy on a blind fool and point me in the right direction I'd be forever in your debt.
I solved similar problem few years ago as my bachelor and diploma thesis. I designed a Cascade, an executable structure which forms growing acyclic oriented graph. You can read about it in my paper "Self-generating Programs – Cascade of the Blocks".
The basic idea is, that each block has inputs and outputs. Initially some blocks are inserted into the cascade and inputs are connected to outputs of other blocks to form an acyclic graph. When a block is executed, it reads its inputs (cascade will pass values from connected outputs) and then the block sets its outputs. It can also insert additional blocks into the cascade and connect its inputs to outputs of already present blocks. This should be equal to your task starting another task and passing some parameters to it. Alternative to setting output to an value is forwarding a value from another output (in your case waiting for a result of some other task, so it is possible to launch helper sub-tasks).
I have a fairly involved download process I want to perform in a background thread. There are some natural dependencies between steps in this process. For example, I need to complete the downloads of both Table A and Table B before setting the relationships between them (I'm using Core Data).
I thought first of putting each dependent step in its own NSOperation, then creating a dependency between the two operations (i.e. download the two tables in one operation, then set the relationship between them in the next, dependent operation). However, each NSOperation requires it's own NSManagedContext, so this is no good. I don't want to save the background context until both tables have been downloaded and their relationships set.
I've therefore concluded this should all occur inside one NSOperation, and that I should use notifications or some other mechanism to call the dependent method when all the conditions for running it have been met.
I'm an iOS beginner, however, so before I venture down this path, I wouldn't mind advice on whether I've reached the right conclusion.
Given your validation requirements, I think it will be easiest inside of one operation, although this could turn into a bit of a hairball as far as code structure goes.
You'll essentially want to make two wire fetches to get the entire dataset you require, then combine the data and parse it at one time into Core Data.
If you're going to use the asynchronous API's this essentially means structuring a class that waits for both operations to complete and then launches another NSOperation or block which does the parse and relationship construction.
Imagine this order of events:
User performs some action (button tap, etc.)
Selector for that action fires two network requests
When both requests have finished (they both notify a common delegate) launch the parse operation
Might look something like this in code:
- (IBAction)someAction:(id)sender {
//fire both network requests
request1.delegate = aDelegate;
request2.delegate = aDelegate;
}
//later, inside the implementation of aDelegate
- (void)requestDidComplete... {
if (request1Finished && request2Finished) {
NSOperation *parse = //init with fetched data
//launch on queue etc.
}
}
There's two major pitfalls that this solution is prone to:
It keeps the entire data set around in memory until both requests are finished
You will have to constantly switch on the specific request that's calling your delegate (for error handling, success, etc.)
Basically, you're implementing operation dependencies on your own, although there might not be a good way around that because of the structure of NSURLConnection.