Bug 34772

GemStone/S

6.1.6, 6.1.5, 6.1.x, 6.0.x, 5.1.5.1

All

6.2

Risk of stone hang due to stuck spin lock

Spin locks are internal mechanism that synchronize access to the shared pages.  Processes acquire a spin lock, perform an activity, and release it as quickly as possible.  When a process is terminated, if it was holding a spin lock when it was terminate, it is usually, but not always, possible for the shared page cache monitor to clean up the spin lock and continue.  In some cases, the stuck spin lock is not safely recoverable and the stone must shut down.

There are rare cases where the stone may attempt to acquire a spin lock before the shared page cache monitor has a chance to handle it (by either recovering the slot or terminating the system).  In this case the stone may hang, rather than shutting down.

Workaround

You should carefully avoid terminating processes in ways that risk creating a stuck spin locks.  While it is rare for an unrecoverable stuck spin lock to cause the stone to hang rather than shut down, stone shutdown is also an undesireable occurance.

The fix for this bug includes terminating the stone rather than
hanging, and improved log messages.


Last updated: 6/13/08