What does a "potential stuck thread" message mean?

By itself, a potential stuck thread message simply indicates that a task is taking significantly longer than the AMPS engine expects.

AMPS includes a thread monitor that keeps track of how fast AMPS threads are processing the work provided. If a thread does not report progress when expected, AMPS logs a 30-0000 message indicating that the thread has missed an expected check in. This could indicate that an operation is taking longer than expected, or it may indicate that the thread is unable to make progress. AMPS logs these messages proactively, before the slowdown would necessarily cause problems, so that if an issue developers, troubleshooting can determine when the issue started and what thread was affected first.

For example, an operation involving a large file may take an unexpectedly long time on a busy SAN and cause AMPS to report that the thread performing the operation is stuck. Likewise, if an AMPS instance is located on a server with other processes that require large amounts of CPU, network, or storage capacity, AMPS may report a potential stuck thread when AMPS is unable to acquire enough resources to make progress in a timely manner.

Information in the logs previous to the potential stuck thread message can help you diagnose why a thread may be stuck. Inspecting the network usage, memory pressure, and CPU load average on the system running AMPS at the time the messages were generated may also help to troubleshoot the reason for the stuck thread message.

When the problem persists, AMPS may generate a minidump to help 60East diagnose whether the potential stuck thread is a problem in AMPS or a problem with the system. In these cases, providing load information for the system with the minidump and logs can help 60East diagnose the problem.