Diagnosing Blocking issues using Blocked Process report

I have an application that is going down as a result of timeouts. During these times we see a massive spike in response times from the database that holds ASP session state.

In an effort to to diagnose the issue I have used SP_CONFIGURE'blocked process threshold',15 and ran a trace to catch any events that are fired. During the next incident the trace capture some blocking events in the Session State database.

I've identified the lead blocker and can see that it's suspended and waiting.

<blocked-process-report><blocked-process> <process id="process53fb4c8" taskpriority="0" logused="0" waitresource="KEY: 10:72057594039238656 (594b17b7493c)" waittime="20631" ownerId="9710782702" transactionname="UPDATE" lasttranstarted="2013-06-27T17:29:38.130" XDES="0xc429df950" lockMode="U" schedulerid="14" kpid="6912" status="suspended" spid="359" sbid="0" ecid="0" priority="0" trancount="2" lastbatchstarted="2013-06-27T17:29:38.130" lastbatchcompleted="2013-06-27T17:29:38.107" clientapp=".Net SqlClient Data Provider" hostname="WEB03" hostpid="7520" loginname="State" isolationlevel="read committed (2)" xactid="9710782702" currentdb="10" lockTimeout="4294967295" clientoption1="536870944" clientoption2="128056"> <executionStack> <frame line="18" stmtstart="1114" stmtend="4494" sqlhandle="0x03000a00210f020741a1be0058a000000100000000000000"/> </executionStack> <inputbuf> Proc [Database Id = 10 Object Id = 117575457] </inputbuf> </process> </blocked-process><blocking-process> <process status="suspended" waittime="1046" spid="217" sbid="0" ecid="0" priority="0" trancount="1" lastbatchstarted="2013-06-27T17:29:29.113" lastbatchcompleted="2013-06-27T17:29:29.010" clientapp=".Net SqlClient Data Provider" hostname="WEB02" hostpid="6236" loginname="CState" isolationlevel="read committed (2)" xactid="9710776428" currentdb="10" lockTimeout="4294967295" clientoption1="536870944" clientoption2="128056"> <executionStack> <frame line="18" stmtstart="1114" stmtend="4494" sqlhandle="0x03000a00210f020741a1be0058a000000100000000000000"/></executionStack> <inputbuf> Proc [Database Id = 10 Object Id = 117575457] </inputbuf> </process> </blocking-process> </blocked-process-report>

I think I need to figure out 1) What the unit of time is for waittime="1046" 2) What resource is the wait on 3) Where to go from here!

Thanks in advance.