Overall, between these two EMR-related commands, another way of looking at this topic/question (to me) is transient vs. long-running.
Based on this research, I'm unsure if create_cluster can do anything that run_job_flow can do (but not the other way around). It seems the main thing to configure is just the KeepJobFlowAliveWhenNoSteps property.
Is what I've stated above valid and complete?
Related
I'm building a student schedule generator and I need a way of producing more than one solution. Is there some way to save off feasible scores or scores of Xhard/Ysoft?
I need to be able to output more than one potential schedule, that way the student will have a choice for one schedule over the other if for whatever reason they don't want the "best" schedule (maybe they don't like one of the professors, maybe they don't want an 8am class, whatever)
My original idea was to save off all feasible solutions using the bestSolutionChanged event listener. The problem with this, is that once it finds a 0hard/0soft score, it ignores all scores after that, including scores that are equal.
Ideally I'd like to save off all scores of 0hard/-3soft or better, but just being able to save any feasible scores or force optaplanner to look for a new best score would be useful as well.
This is not a solution, but an analysis of the problem:
Hacking the BestSolutionRecaller is obviously not just a big pain, it's also behaviour we don't want to encourage as it makes upgrading to newer version an even bigger pain. So don't expect us to solve this by adding an easy way to configure that in the solver config any time soon. That being said, a solution for this common problem is clearly needed.
When a new best solution is found, it is planning cloned (see docs for definition) from the working solution (the internal solution in OptaPlanner). This allow us to remember that new best solution as the working solution solution changes. That also means the BestSolutionChangedEvents gets a plannng clone and can safely ship it to another thread, for example to marshal it to a client (presuming any ProblemFactChanges you create do copies instead of alterations), without being corrupted by the solver thread that modifies the working solution.
New best solution imply that workingScore > bestScore. The moment it instead does workingScore >= bestScore, we need far more planning clones (which are a bit CPU expensive), but we could then just send out BestSolutionChangedEvents for that too, if and only if a flag is enabled of course, because most users (unlike yourself) don't want this behaviour.
One proposal is to create a separate BestSolutionChangedOrSameEvent, next to the BestSolutionChangedEvent. This might not be ideal, because we need to be able to detect whether or not someone needs those extra planning clones.
Another proposal is to just have a flag in the <solver> config that switches from > to >= behavior for BestSolutionChangedEvent.
Please create a jira (see "get help" on webpage) and link it it here, or create a support ticket (also see "get help" on webpage).
I know its not best practice but its the most performant solution I have found so far. It monitors an object, and transforms that object in the autorun.
This setup is working excellently for small data sets, but when there are a lot of changes, it gets stuck in the "100 cycles and didn't settle" error.
I was wondering if there was some way to get it to iterate just once / collate all changes and apply them in one hit.
I have tried a number of solutions / workarounds that involve timers, deep object comparison (ie don't run if it hasn't changed) etc, but they either disable the autorun or lead to extremely bad performance.
I guess in summary:
Is there some way to make autorun not execute changes on the same frame?
Is there a better solution for autorun to watch every observable in an object?
Is there a way to limit autorun?
Is there a better solution?
It is hard to say anything useful without some minimal code example of what you are doing. But it sounds like you are reading and modifying the same data in the autorun, which introduces cycles. Consider using reaction which allows you to better separate what data you want to listen react, versus the action you want to take once a change occurs
In the change and swap move selector, I would like to only consider moves that involve entities in conflict as they are more likely to improve the heuristic score.
How should this be done? What classes and interfaces do I have to reuse/extend? I looked at ScoreDirector and PhaseLifecycleListener.
A MoveFilter might do that (if it's not in phase or solver cached as it changes ever step). See the course scheduling example and docs for how to use a filter.
I wouldn't recommend it though, as you still want to move non-conflicting entities at times. You might just want to focus more on those conflicting lectures. So I would keep a vanilla move selector in the mix.
The move filter isn't perfect either - the Guided Local Search feature (not yet available) is a better way to deal with this.
However, given the other question about the model and similar cases I 've seen, I 'd say moves are not your problem. A better model will make all these kinds of move tweaking obsolete.
I'd like to use sails-redis to track all kinds of events.
Therefore I need the ability to increment model attributes in a performant way.
I already found the Model.native function, wich allows me to access the native redis methods.
But since sails-redis is based on Strings and not on Hashes I can not use any native increment methods (so far i know).
Is there any clean and performant way to solve this issue?
The thing sails-redis does is to create a database with CRUD methods by using redis key-value-store based on strings.
Therefore do not see sails-redis as an wrapper for redis. Forget about that. It is just another database which almost has nothing to do with redis.
Use the right tool for the right job!
I you have a job like event tracking where you want to use Redis because of it's speed use node-redis and implement it yourself. sails-redis is just not made for such things.
I simply created a new service and used node-redis. There might be a more elegant way, but mines works and improved performance a hole lot.
https://github.com/balderdashy/sails-redis/issues/34
In a program that I'm responsible for, we want to start keeping track of milestones. These milestones are quite simple and consist of a unique identifier, the project they're assigned to, a description, and a date that they should be accomplished by (or not, if there's no concrete due date).
We use a slightly modified Model-View-Presenter architecture, and currently I'm passing this list around through the presenters, but it seems fairly clunky, so I was wondering:
What's the best way to make this list available to all the presenters/views that need it?
We're using VB.NET 3.5, and I was toying with the idea of making this a shared property of the main presenter, but it does seem like that adds some unnecessary coupling.
I agree with Oded about keeping it as you have it, but if you insist on having it the way you describe, you could consider implementing it (the collection) as a singleton.
Have a read through this article