Tuesday, November 10, 2009

Viewstate error : 12031

Few days ago I was asked to look into an issue. In our application we have created dynamic grids to show data from database. This ASPX page was Ajax enabled. Moreover all the rows of the grid were in edit mode ie. the normal controls like textbox,dropdowns etc  were displayed in all the rows. This grid was Paginated. But for the past few days the paging was not working.
I executed the page and found that the page was generating an error 12031  with the following message

Sys.webForms.PageRequestManagerServerErrorException:An unknown error occurred while processing the request on the server .the status code returned from the server was:12031.

On my first round of analysis I found the issue with Viewstate. If the viewstate is large then connection is reset (ERROR_INTERNET_CONNECTION_RESET ). In local machine with less load this problem will not occur but as the load & network latency increases this error will come. Once this error is generated the general events of grid is not triggered. So advised my team to minimize the use of viewstate. It will help in to load the page faster & reduce the network traffic. I can increase the maxRequestlength value to allow more data but ideally i shouldn't increase that.

In the page tested by me a page with grid  with 372 rows generated a viewstate of 4.2 mb. you can disable viewstate using EnableViewState="false" for the individual controls and for the entire page also.

With every post back this much of data is transferred back & fro & this will result in low response time.
The developer was saving all the data into viewstate in page load and from that the data was populated to the grid.
Better solution is to retrieve only the required data from database, minimize the use of  viewstate, Viewstate can be compressed also. About all these I will update in another post.

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