title: Sharepoint Concurrency Issue
body: <p>I am totally new to Sharepoint development (Sharepoint 2013), and could use some help.</p>
  <p>I inherited a console application where I'm getting this message below:</p>
  <p>Your changes conflict with those made concurrently by another user. If you want your changes to be applied, click Back in your Web browser, refresh the page, and resubmit your changes.</p>
  <p>Actually, within the application and another console application (both running as jobs), there are numerous using blocks where they are newing up SPSite and SPWeb, opening the same list, and looping through the entries and posting update. These loop are incredibly slow. So the SPSite and SPWeb stays open for a long time, while additional SPSite/SPWeb are new'ed up to the same list.</p>
  <p>Should I new up only one SPSite and SPWeb per application and use them globally within the application? Should I grab my list objects and assign them to a .NET List and close out the SPSite/SPWeb and then when I'm ready to update the record to temporarily new up a SPSite/SPWeb for the duration of the Update()? These list items are being updated by the other job as well while marching thru the list and posting updates to the same list. Is that an issue?</p>
  <p>In reality, the notion of a Error Log list exists as well. Items are constantly being appended to this list. Would that cause that error message above?</p>
  <p>Would create a Retry loop for the Update() work? Or is the issue of the list item updated by another process prevent a successful update?</p>
  <p>Thanks.</p>