Database Reference
In-Depth Information
Resource details ( [0x1650015][0x351eac],[TX])
Granted_Q: lp 1657e67440
Convert_Q: lock lp 16112f5ec8
Lock structure details lp 1657e67440
Process details
Lock structure details lp 16112f5ec8
Process details
Figure 11-3. LMD trace file structure
Now, let me explain the details about each of these sessions. The following lines show the starting point for this
resource dump in node 2 after a deadlock detection event. LMD process detecting the deadlock is starting to write
deadlock information:
*** 2012-10-06 15:37:08.013
Global blockers dump start:---------------------------------
DUMP LOCAL BLOCKER/HOLDER: block level 5 res [0x1650015][0x351eac],[TX][ext 0x0,0x0]
Nearly at the same time, the following lines are written to LMD trace files in node 1, indicating that a dump
request was received by the LMD process in node 1 to dump details about resource and lock structures.
*** 2012-10-06 15:37:08.018
ENQUEUE DUMP REQUEST: from 2 spnum 12 on [0x1650015][0x351eac],[TX][ext 0x0,0x0] for reason 3
DUMP LOCAL BLOCKER/HOLDER: block level 5 res [0x1650015][0x351eac],[TX][ext 0x0,0x0]
The first section of the dump file prints the resource details. In this case, the resource is a TX resource; as we
discussed earlier in this chapter, row-level locks are implemented through TX resources. The next three lines show details
about the local instance, directory instance, and master instance. The master instance is the resource master instance.
----------resource 17cfa16ca0----------------------
resname : [0x1650015][0x351eac],[TX][ext 0x0,0x0]
hash mask : x3
Local inst : 1
dir_inst : 1
master_inst : 1
...
The following few lines show existing grants on that resource. Count line indicates number of locks in that mode.
In this example, there is a NULL mode and an exclusive mode lock on this resource. Value block from the resource is
also printed. Generally, value block is not useful for debugging deadlocks though.
 
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