This is site for trading which is will be blur before the market open.
Now My aim to make a exact timing using algorithm or any other way.
For example, If my market open at 11:00:00. Then how can I make a order at the same exact time.
One approach to this aspect is through api-s provided. Any decent trade platform should provide.
You could do an implementation with php and curl to place orders (and if api do not have a start date and is based on system time then schedule with cron).
Without any api you could try with some testing tools (Selenium with java) and maybe use a scheduler.Since you have to pass trough all clicks till reach place order, maybe it's better to schedule sooner all the action and wait till start time and then simulate place order by click
Related
I'm trying to make a simple app using Flutter, cryptocurrency price tracker. Using this API to retrieve a data. That how it looks:
The problem is, it only retrieves the latest data and do not updates as the price changes every time. It will change only after restarting an app. I was thinking to add a floating refresh button but i seems an old school. SO my aim is to let it update the price by itself,in real time(LIVE) without USER doing something, every time there is a change in price. My question is, what technology is behind this ? How could I implement this ? What should I Google in order to find the required knowledge ? Who could give me the right direction to think and learn. I don't really know the special terminology for this concepts, tried my best to explain the question. Thnx!
How could I implement this ?
Following are the steps that you need to follow.
Create a stateful widget with a Periodic Timer object. setup the timer value, say 10 seconds.
Now you will get a callback for every 10 seconds. So, from that callback method, simply call the API end point to fetch the latest data.
Use setState method to show the latest data on the UI.
Thats all, now your app will refresh the data by its own for every 10 seconds without any user interaction.
You can use web sockets.
https://flutter.dev/docs/cookbook/networking/web-sockets
This will let you push updates to the client without polling in real time.
Building a simple application which restricts usage based on the date. For example, you can only view a page 3 times per day.
However, if I use the device time, users can change their time and then view these pages again.
Is there another best practice method of doing so? Trying to avoid a call to the server. Using react-native. Thanks
Best practice is only use server time.
you can use following lib
https://github.com/artem-russkikh/react-native-clock-sync
This is kinda tricky without hitting the server.
into
Let's assume that the first time they open your app the user date is correct. (I really don't know any other way checking that in an offline way)
That moment we need to save the current timestamp to the localstorage (called AsyncStorafe in RN).
solution
The only way you can really be sure that the timestamp is correct is keep a task that counts every seconds/minute/hours, whatever is logical in your situation.
issue
Doing this in react native won't get you that far, but we are able to make a Java background service for example that we start as soon as the app closes. Here you should keep up with the time and save this when the app launches to a place where it's also accessible from react native (not sure if AsyncStorage is).
Info
Here you can find some information about bavkground tasks in RN: https://hackernoon.com/easy-os-background-tasks-in-react-native-bc4476c48b8a?source=linkShare-cdf0b7d5ccb4-1538965801
The most secure amd easy way of time cheat prevention is by hitting the server vut if that's not a possibility that this may be a interesting way to still check it. Good luck!
My goal is to maintain "real-time" (or as close as possible) information about the email messages sent by a group of users.
My ideal solution would be to periodically query the API for messages by all users in the group. This feature is not (yet?) implemented.
My second choice would be to create subscriptions (https://graph.microsoft.io/en-us/docs/api-reference/v1.0/api/subscription_post_subscriptions) for every member in the group and then request message information after I become aware of an event. The problem is, in practice, I am only allowed to create 20-30 simultaneous subscriptions (Issues to use Webhook for Microsoft Graph API), which might not be enough.
So I'm stuck with polling all the users in a cycle. The main problem with this approach is I can't find any information how many request are "too many", ie I get throttled. I want to maximize the number of requests to minimize the time it takes to get through one cycle.
A solution that comes to mind is to develop an adaptive program that slowly decreases the time between requests until throttled, then abruptly adds some time to it until a nice balance is found and maintained. This seems like a lot of work though. Right now I'm working on the assumption that 1/second is about the highest I can safely go (0.5 seconds on average per round trip, then a cool down of another 0.5 seconds).
What is the best way to deal with an unknown throttling limit in general, and Microsoft Graph in particular?
Edit:
While I think the accepted answer is a good response, it might not be suitable for all cases. For instance, if you don't want to use the 365 API, and you don't mind using beta features, perhaps you might check out this (delta tokens), which seem to be designed for real-time syncing with the data.
The only potential downside with the accepted answer is that you still need a subscription for each user you want to track (I think...), and there are limits on those. Very curious as to how other people tackled this problem.
While still in Preview, you may want to take a look at Outlook Streaming Notifications. These APIs provide a more robust notification model than simple web hooks. You would still need to establish multiple subscriptions but I expect you'll see far less latency.
I have downloaded the JMeter and played around it. It is working fine. I have one quick question. I need help in this.
Using JMeter tool How can I say that given webserver handles efficiently n number of user at the given second or minute.
.
Please help me as soon as possible.
Thank You
Regards
Ganapathy
Answer to that question is the very reason why we do performance testing.
We primarily want to find out how application response time grows as we increase the number of parallel users.
To find out you can start with jMeter Plugins Ultimate Thread Group to gradually add users during a test.
To visualize test results, use Response Times vs Threads graph, which also comes with jMeter Plugins.
But that graph only shows average response time for specific number of users. To include time component use Composite Graph in which you'll include number of threads (users) and response time and you'll be able to see real time how response time changes with number of users.
That's where I'd start.
Try to increase the number of requests (and threads that fire requests) and see how the answer time behaves. Part of the answer is the question which response time is acceptable for you. Also note that this will not be equal to real users as you are firing requests from a single machine and in a manner not comparable to real users requesting real pages.
Read this comparison, it may help you.
I want to simulate our whole checkout process under load. This essentially involves running a number of POSTs in sequence, where the client is storing a unique cookie for each sequence that allows the session to be preserved. Can anyone recommend a software or service that meets these conditions?
This sort of thing could be very easily, effectively and freely accomplished using Apache JMeter. You can either record the journey using JMeter's proxy or simply add the requests manually.
To simulate cookies add a Cookie Manager to the testplan. For any other tokens or session ids that need to be correlated you can use a Regular Expression Extractor.
There are lots of options for this kind of test. Free/open-source tools will require a bit more work on your part but are otherwise free. Tools like ours (Load Tester 5) will get the job done much quicker, but there is a cost for the software. If your organization does not have much experience with load testing and are on a tight schedule, you might want to bring in outside help to help you meet your deadline and learn the process (we offer services as well!).