ssrs processing time spikes - reporting-services

I'm developing a report in ssrs for display in a public location within the company. The report shows up-to-the-minute data on department activity, so is set to refresh every 30 seconds or so.
The problem I'm running into is that once every few hours, the report throws an error (rsErrorReadingNextDataRow) & (rsProcessingAborted). All I have to do is hit refresh in the browser (rendered in a an internet browser) and it reruns and charts along happily for a while.
After looking at the reportserver execution log, it appears that these errors coincide with a phenominal spike in processing time. On average, each time the report refreshes, processing times is 400ms~800ms, but when it spikes it goes to ~90000ms (yes, five zeroes) and then throws this error.
Being new to SSRS I am not sure where to begin looking for the root cause.
Can anyone give me pointers as to where I can start to find out what is causing the processing time to rocket like that? Data retrieval is stable at ~5000ms, and Time rendering is stable at around 200ms. It's only the processing that goes haywire.
Some background on the report and data:
Data is pretty straight forward. It's based on a view that pulls transactions from last 7 weeks. Number or records, therefore ebbs and flows each week ~ 8000 records. When select * from View is run in SSMS, query takes about 5 seconds to run. I'll work on speeding that up after I resolve this processing issue.
No parameters are used, though the view does use getdate() to figure out which records to show from base tables.
No stored procedures are used.
Report itself is comprised of 6 panes within a single tablix, none of which have to draw more than a few dozen marks ('cept one is a map of US states).
The report does have one feature that may be related, though I am not sure how. Report definition filters the dataset based on a mod 3 of the built in execution time variable, rotating the report to show "This Month", "This Week", or "Today" activity. There is an additional mod 3 on execution time which rotates visibility for the panes. The result is that each 30 seconds, a report with different combinations of charts shows up on a rotating time-frame.
Don't know if this could be a cause, but it's the only element of the report that makes it remotely fancy. Everything else about the report is actually rather straightforward/plain.
While I would love to identify and eliminate the spikes, even a mechanism to automatically refresh on error, or refresh on timeout (or something to that effect) would do the trick. I need to be able to launch the report in the morning and have it run unmanned all day without any human interaction, refreshing every 30 seconds for the duration of business hours.

Just a recap of the comments:
it might be possible to push the web page into a frame, then add javascript to the main page to periodically refresh the frame. It wouldn't fix the underlying problem, but it might help.
it might be worth looking at the performance monitoring tools in Sql Server - it might be a database issue (temp table filling up, etc)
You noted that adding a with (nolock) seemed to help locate the problem.

Related

MS Access: Multi-User Application: send msgbox to specific user

I don't know if my idea is possible to solve with MS Access. The requirement:
I have one centralized DATA-database and several Client-Databases. It will be used to maintain a rescue team in our company. Each one has to press a button in his client and in the reception client is visible who is available in case of an emergency.
It even shows who is in which corner of the building the rescue person is.
Now, it's in human nature that in evening People forget to logout. Plan is to define a usual end of work time. The reception client verifies every 5 Minute if someone reaches his end of work time and can set him as out of office.
Problem is, perhaps Mr. X works today not until 17h as usuall - today he is available until 20h.
So, a message should Pop up 15 Min before his end-of work and ask him if he goes by time or not. If he answers to work longer, a flag should remove him from this function today.
Solution is almost 70% developped. Problem is now the little point, how to pop-up the message to the right user. One Idea is to check a message table if there is a message for him.
But, i don't like to make to much LAN traffic... if each client ask every 5 minutes the DATA DB if there is a message for him.
Has some one an idea?
Best regards
Roland
Polling a single table every 5 minutes should generate virtually no load. I've used a similar solution that polls every minute without any trouble on a networked database with ~20 users.
You can, of course, pull in these messages once, since they will fire at a set time, and then just raise them at that time.
You can just have a hidden form that's bound to a specific table, uses a filter on the username, and requery every x seconds, tests if there's a message ready, and then displays it.
Alternatively, you can pull in messages once, and have a hidden form that checks on timer if it's time to raise that message.

Why does SSRS need to recycle the application domain

I'm working with MS Reporting Services 2016. I noticed that the application domain is set by default to recycle every 12 hours. Now the impact on users after a recycle is either slow response from reporting services or a failed report. Both disappear after a refresh of the report, but this is not ideal.
I have come across a SO answer where people suggest that you can turn off the scheduled recycle by setting the configuration attribute RecycleTime to zero.
I have also read that writing a script to manually restart reporting services, which also recycles the app domain. Then a script that simply loads a report at a controlled time to remove the first time load issues. However this all seems like a work around to me and I would rather not have to do this.
My concern is that there must be a logical reason for having the scheduled recycle time, but I cannot find any information explaining this. Does anyone know if there is a negative impact from turning off the scheduled application domain recycle?
The RecycleTime is a function aimed at making sure SSRS isn't consuming RAM it doesn't need and potentially starving the rest of the machine. Disabling the refresh essentially removes the ability to claw back any memory used for a brief period of intensive processing.
If you are confident your machine is suitably resourced you can turn the refresh off or, if not, alternatively schedule the refresh for an out of hours time and define a Cache Refresh Plan to cache any super important reports immediately afterwards to minimise any user impact.
Further reading here: https://www.mssqltips.com/sqlservertip/2735/prevent-sql-server-reporting-services-slow-startup/
I guess I'm possibly over simplifying this, but SSRS was designed to recycle every 12 hours (default) for a reason. If it ain't broke, don't fix it. In my case, I wanted to control when the recycle occurred. I execute a 1 line powershell script from a SQL Agent job at 6:50 am, then generate a subscription report at 7 am, which kick starts SSRS and the users do not see any performance degradation.
restart-service 'ReportServer'
Leaving the SSRS config file setting at 720 minutes lets the recycle occur again at 6:50 pm. Subscription reports generate throughout the night, so if a human gets on SSRS after hours there should be no performance issue because the system is already running.
Are we possibly overthinking it?

Data driven SSRS subscription delayed execution on the first run

I have a weird issue with one of the data driven subscriptions on SSRS.
The subscription is a timed subscription that generates invoices (pdf/excel) and gets triggered by a stored procedure.
The issue we are facing is that the first run always takes 30-60 minutes regardless of how many invoices are being generated. Once the first run has completed the subsequent runs are completed under a minute throughout the day.
There is a second version of the same report that is run manually and it runs fine(ruling out any delays with the data extraction bit).
I have looked at some other questions here but that didnt help identify the problem:
SQL Reporting services: First call is very slow
SSRS report subscription not working sometime
Without knowing more about the query, data, database setup, other process, etc.; it will be quite difficult to say for sure. But if I had to guess, based on your description, it sounds like the query plan cache is lost and is rebuilt on the first run of the day. Without the plan the query can be less efficient. Each subsequent run will use the plan created on the first run, and will therefor run more quickly. There are a number of reasons that could cause the query plan to be wiped from cache. A recompile, other queries using too much memory, not enough system memory to begin with etc.
Hope that helps!

I have SSRS auto report refreshing every minute. I takes long time to refresh and shows loading

I have SSRS line graph which is to be auto refreshed every minute. I takes a long time to refresh and shows loading icon until it is refreshed and the graph becomes blurred.
How to reduce the refreshing time and how to refresh the report in background and not to show the loading icon?
Reducing the report refresh time
In most examples, the bulk of the time taken to refresh a report will be due to the dataset queries running. Therefore you should start by looking at those queries and investigating how they can be optimised to execute as fast as possible. As noted in the comments there are options to cache reports for performance, but given your requirement to refresh the report every minute I am assuming you will want the latest data, not a cached version.
Refreshing the report "in the background"
As far as I am aware, this is not possible.
It would seem a snapshot would be the way to go. You can set up Snapshots under the Processing Options tab when managing the report. With a snapshot, SSRS runs all the queries behind the scenes at a set interval or schedule. Then, when the user accesses a report, the only loading time is for the presentation layer.
That said, if a user tries to access a report while SSRS is running a snapshot, then the user will wait until the snapshot is finished, and thus the loading screen will appear. I would recommend you follow Nathan's advice and work on query optimization.

Subscriptions delayed behind single report running thousands of times

I find it difficult to think I'm the first to run into this so either my searching ability has truly become sad or the solution is so apparent that nobody has asked before. Mox nix, I must ask.
SSRS 2012 which has a few hundred reports on it, over a hundred subscriptions and generally speaking, works fine.
This is a Native box, we have a separate box for the SharePoint version.
The monthly 'statement' report is data-driven and is fed over 100K personIds to process and export to pdf on a file server. The SQL takes .3 seconds, the pdf not much more. There are just so many of them. So when this one runs, all others queue up behind it and wait, often for it to completely finish. Not good. Month end reports are important to a few departments.
My question- can I set the priority of this report somehow (or some other setting) to allow for other reports to process when they are scheduled?
It just boggles my mind that this is even an issue, but it is.
Thanks for any insights-
Craig
There's no way to set an individual report's priority, unfortunately.
I would look at either reducing the number of required executions, if possible, and failing that, you can try manually separating them into batches, and assign a different subscription to each batch. Sub 1 could handle rows 1 - 5000, sub 2 5001 - 10000, and so on. Stagger the execution times and it will allow other subscriptions to slip in 'in between' the batch processing subscriptions.
But really, if you truly need to generate 100k-plus reports, I don't think SSRS is the best option. Have you considered SSIS instead?
Dean Kalanquin has an excellent examination of how subscriptions in SSRS work, if you're looking to see what's happening under the hood :
http://blogs.msdn.com/b/deanka/archive/2009/01/13/diagnosing-and-troubleshooting-subscriptions.aspx