Why data is loading slow for node level data page in production only for the first user?
Asked in an interview-we have a data page of node type scope and it has 10,000 records, there is a change made on sunday evening in production and on monday morning it takes time to load the data for the first user but for second user it works fine can you tell me why is this so?
Areteans Technology Solutions Pvt. Ltd.
IN
@TanyaS58 This is because once the change applied the data page must be flushed to refresh and get the changed/updated data in page. Hence when 1st time the data load on node level page it has to hit DB to get the data so it can take some transaction time for loading data initial for the 1st time. But from the second time as data is already loaded so it will be faster cause data is already updated in data page and no need to load it again from DB.
Hope this clarifies your question.
Cognizant
IN
@AmarTiwari So in this scenario it will be better to flush the data page ?and then it will not be slow to load the data even for the first user?
IQZ Systems LLC
US
@TanyaS58 Also incase multi node environment, each node will have the copy of the Dpage. So whenever the node is restarted and the first user who tries to access data should have to wait, until the node loads the whole data into the Dpage. Second user who tries to access does not need to wait, the cached Dpage will be accessed.
Hope it helps.
Cognizant
IN
@KiruthikaAcan it be due to the refresh strategy configured like Reload if Older Than and maybe that time frame has expired so the contents are reloading again?
Updated: 28 Sep 2023 1:33 EDT
Tata Consultancy Services
IN
Hi @TanyaS58
I think you are still not getting the point.
Process Commander will check first If the data is available/ not available on the clipboard, If the data not available on the clipboard, then Data Page gets the data from the database and places it on the clipboard for the first user. (Technically speaking, it is not first user, first time Data Accesing from the DB/Fisrt time case creation time while data is not available in the ClipBoard.)
From the Second time/Second time case creation/second user onwards, it gets used from the clipboard.
It doesn't matter about load management; Maybe somebody clear flush so that we can't assume that data get auto flushed like that, if the data is not available in the clipboard, DPage will get data from the DB and places in the clipboard.
You can try the clear flush in Dpage. Create one case (using the Node/Requestor level data page), put stop watch for the first time, and create another case and put stop watch, mean while turning on the tracer (you will see first time case creation Dpage will called and from the second case creation time Dpage itself will not be called, i.e., data loading from the clipboard).
Note: The difference between the first and second few seconds is only that, not more than that.
I hope now bit clear on this.
Thanks,
Ashok
Cognizant
IN
@Bhumireddy actually I wanted to know is it also possible due to the refresh strategy? Say for Reload if Older Than and maybe that time frame has expired so the contents are reloading again when the data is accessed first time after the change is made?
Updated: 28 Sep 2023 8:47 EDT
Tata Consultancy Services
IN
Yeah, Based the on the refresh strategy, Data Page automatically flushed. It we didn't defined any timing, So that system automatically flushed every 24 Hour's
We mention Duration Days hours minutes seconds to refresh the data page from servers clipboard.
Reload once per interaction : For interaction that an user makes requesting for Data page , it will be refreshed.
Clear Data Button : When we click on this the data page gets deleted from clipboard.
When we click on this button PRPC internally calls an OOTB activity ‘FlushDeclarativePage”.
Could you please refer below article it gives more deatis
https://academy.pega.com/topic/refresh-strategies-data-pages/v1
https://onestoppega.com/data-modeling/data-page-configuration-usage-execution/
Note: The use of a refresh strategy is optional but strongly recommended for data pages to prevent users from viewing and acting upon stale data.
Thanks,
Ashok