Tag Archives: DB2 9.7

Painted into a Corner

I’ve had such good success with DB2 9.7 LUW under 64-bit Linux that I didn’t hesitate to install it on my new development laptop (Windows XP 32-bit, the corp-rat standard).  I immediately upgraded to Fix Pack 2, of course: never install fix level zero of anything.  I created and loaded a few databases and was on my way.

But it didn’t take long to notice some very bad behaviors.  I saw frequent CPU, memory, and I/O spikes, mostly in db2syscs and db2dasstm. On two occasions, all database operations froze without recovering, and db2syscs suddenly became a diehard: I couldn’t kill it from the Service Control Panel, Task Manager, or even pskill.  Windows shutdown then froze, requiring a hard power off.

This sent me on a fact-finding mission.  First stops: the Windows Event Viewer and db2diag.log.  Since I had not changed diagpath, I had to remind myself that instance information files are no longer under SQLLIB (with Windows, they’re now under Documents and Settings\All Users\Application Data\IBM\DB2). I spotted a huge and growing db2diag.log, at diaglevel 3.  It was flooded with messages like:


2010-07-23- I82554H352         LEVEL: Error
PID     : 260                  TID  : 536         PROC : db2dasstm.exe
INSTANCE: DB2                  NODE : 000
EDUID   : 536
FUNCTION: DB2 Tools, DB2 administration server, SchedulerThread_run, probe:5
DATA #1 : String, 50 bytes
Cannot complete scheduler thread’s initialization!


The db2diag flooding would certainly account for the CPU, I/O, and memory spikes, but I’m not sure about the periodic freezes.  But it’s one thing at a time, and couldn’t stop until I had a clean db2diag.

Fortunately, I found a fellow victim who reported the same issue just yesterday.  The root cause was that the DB2 Admin Server (db2dasstm) did not have required authorities on toolsdb.  This was surprising, since I let db2setup create and configure it.  But I’ve been accustomed to chanting the grant dbadm mantra since the introduction of SECADM, so I typed it out.

But in this case, it wouldn’t work. I couldn’t get into toolsdb with an authorization ID that had SECADM in order to do the grant. I tried stepping into it first via SYSADM/SYSADM_GROUP, but no dice. And toolsdb was unique in that SECADM was only granted to some bogus “SYSTEM” ID.  Thank you, db2setup, for painting me into a corner!

To fix it, I had to drop and re-create the toolsdb, following the proper steps to keep DAS happy.  A couple of db2admin stop/starts later and I had a small and steady diag log.

Time will tell if additional problems remain that contributed to the freeze problem (so far, so good), but I learned an important lesson: never let the DB2 installation program create the toolsdb.