I am trying to record the time taken between 2 sensors being activated
I am using ladder logic for my university project although struggling with code to record time taken between two events so as to store the information
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I am working on a report to monitor certain things on the Power BI report Server. I was wondering what items others may be monitoring on reports and how do they do it.
Some examples of things I want to monitor:
A. Whether the scheduled data refreshes failed or succeeded.
Would love to be able to get the failure message.
B. What is the average response time of a query.
Is there a way to determine when the report is first opened. I would like to calculate initial load time.
C. What was the longest response time of a query per day.
D. How many times a query took longer than 5 seconds.
I need to provide the business with a report estimating number of users (devices in this case) the system can cope with without extensive delays and errors.
Assuming each device polls-communicates with the server every 5 seconds or so would it be acceptable to multiple the number of concurrent users I stress test with by 5 to get the figure required by the business?
In general what are the best means of answering such a question considering the above factors?
I am guessing that the collision rate (making them concurrent) may well be over the ratio of 5 (the seconds it takes for the device before it asks to communicate with the server).
Any advice?
I am using JMeter to produce concurrent user/device throughput.
Edit as requested to explain further:
From an analytics point of view if each device will attempt to connect and communicate with the server every 5 seconds and we wish to receive a response within the time it is ready to re-communicate (in other words in next 4 seconds), the collision chances literally for other devices running the same software is calculated on the elapsed time between the two calls no?
I am looking for statistical analysis methodology really to find a percent to multiply the concurrent test results to a real environment.
I know it is a general question without a specific / explicit answer but more the methodology, if there is one, of how can one project the number of "active" users the system can cope with from the known "concurrent" users. I would have though that given the frequency of calls is known and that each call takes 300ms in average one could somehow project the actual users (maybe by an industry standard multiplier?)
I am building a sensor network where a large number of sensors report their status to a central hub. The sensors need to report status atleast once every 3 hours, but I want to make sure that the hub does not get innundated with too many reports at any given time. So to mitigate this, I let the hub tell the sensors the 'next report time'.
Now I am looking for any standard algorithms for doing some load balancing of these updates, such that the sensors dont exceed a set interval between reports and the hub can calculate the next report time such that its load (of receiving reports) is evenly divided over the day.
Any help will be appreciated.
If you know how many sensors there are, just divide up every three hour chunk into that many time slots and (either randomly or programmatically as you need), assign one to each sensor.
If you don't, you can still divide up every three hour chunk into some large number of time slots and assign them to sensors. In your assignment algorithm, you just have to make sure that all the slots have one assigned sensor before any of them have two, and all of them have two before any of them have three, etc.
Easiest solution: Is there any reason why the hub cannot poll the sensors according to its own schedule?
Otherwise you may want to devise a system where the hub can decide whether or not to accept a report based on its own load. If a sensor has its connection denied make it wait an random period of time and retry. Over time the sensors should space themselves out more or less optimally.
IIRC some facet of TCP/IP uses a similar method, but I'm drawing a blank as to which.
I would use a base of 90 minutes with a randomized variation over a 30-minute range, so that the intervals are randomly beteween 60 and 120 minutes. Adjust these numbers if you want to get closer to the 3-hour interval but I would personally stay well under it
We have a business requirement to show a cost summary for all our projects in a single table.
In order to tabulate these costs we have to query through all the client tasks, regions, job roles, pay rates, cost tables, deliverables, efforts, and hour records (client tasks are in the same table and tasks and regions are in the same table and deliverables, effort, and hours are stored as monthly totals).
Since I have to query all of this before I go for-looping through everything it hits a large number of scripting lines very quickly. Computationally it's like O(m * n * o * p) and some of our projects have all four variables that go up very quickly. My estimates for how to do this have ranged from 90 million lines of code to 600 billion.
Using batch apex we could break this up by task regions into 200 batches, but that would reduce the computational profile to (600 B / 200 ) = 3 billion lines of code (well above the salesforce limit.
We have been playing around with using informatica to do these massive calculations, but we have several problems including (1) our end users can not wait more than five or so minutes, but just transferring the data (90% of all records if all the projects got updated at once) would take 15 minutes over informatica or the web api (2) we have noticed these massive calculations need to happen in several places (changing a deliverable forecast value, creating an initial forecast, etc).
Is there a governor limit work around that will meet our requirements here (massive volume of data with response in 5 or so minutes? Is force.com a good platform for us to use here?
This is the way I've been doing it for a similar calculation:
An ERD would help, but have you considered doing this in smaller pieces and with reports in salesforce instead of custom code?
By smaller pieces I mean, use roll-up summary fields to get some totals higher in your tree of objects.
Or use apex triggers so as hours are entered the cost * hours is calculated and placed onto the time record, and then rolled-up to the deliverables.
Basically get your values calculated at the time the data is entered instead of having to run your calculations every time.
Then you can simply run a report that says show me all my projects and their total cost or total time because those total costs/times are stored/calculated already.
Roll-up summaries only work with master-detail
Triggers work anytime, but you'll want to account for insert, update as well as delete and undelete! Aggregate Functions will be your friend assuming that the trigger context has fewer than 50,000 records to aggregate - which I'd hope it does b/c if there are more than 50,000 time entries for a single deliverable that's a BIG deliverable :)
Hope that helps a bit?
I want to send my current location to php web service after every 5 min even if my application is runing in background. I try to make this thing but its working good when my application in running state but when i put this application in background it stop sending data so please any buddy tell how can i run my application in background.
By "running in background", do you mean running when under the lock screen? If this is the case, then you need to set PhoneApplicationService.Current.ApplicationIdleDetectionMode = IdleDetectionMode.Disabled;
The post Running a Windows Phone Application under the lock screen by Jaime Rodriguez covers the subject well.
However, if you're talking about running an application that continues to run while the user uses other applications on the device, then this is not possible. In the Mango build of the operating system you can create background agents, but these only run every 30 minutes and only for 15 seconds as described on MSDN.
There is a request on the official UserVoice forum for Windows Phone development to Provide an agent to track routes, but even if adopted, this would not be available for quite some time.
Tracking applications are the bulk of what I do for a living, and the prospect of using WP7 like this is the primary reason I acquired one.
From a power consumption perspective, transmitting data is the single most expensive thing you can do, followed closely by sampling the GPS and accelerometers.
To produce a trace that closely conforms to roads, you need a higher sampling rate. WP7 won't let you sample more than once per second. This is (just barely) fast enough to track a motor vehicle, and at this level of power consumption the battery will last for about an hour assuming you log the data on the phone and don't attempt to transmit it.
You will also find that if you transmit for every sample, your sampling interval will be at least 15 seconds. Running the web call on another thread won't help because it will take more than one second to complete and you will run out of sockets in less than a minute with a one second sample interval.
There are solutions to all of these problems. For example, in a motor vehicle you can connect to vehicle power and run hot. You can batch and burst your data on a background thread.
These, however, are only the basic problems faced by every tracker designer. More interesting are the questions of proximity in space and time, measurement of deviation from a route, how to specify routes and geofences in a time dependent manner, how to associate them into named sets for rule evaluation purposes and how to associate rules with named sets of routes and geofences.
And then there is periodic clustering, which introduces all the calendrical nightmares that are too much for your average developer of desktop software. To apply the speed limit for a school zone you need to know the time zone, daylight savings, two start and two stop times and the start and end dates for school holidays in that region.
If you are just doing this for fun or as some kind of hiking trace then a five minute interval will impose much milder power demands than one second sampling, but I still suggest batch and burst because it means you can track locations that don't have comms.