Lockstat Command Output – Locking System Statistics
The Locking System Statistics portion of the sample output is a listing of locking activity for the installation. All values are cumulative from the time ingstart was run for this iteration of the system.
The "Statistics by lock type" portion of the statistics output is described in
Lockstat Command Output – Statistics by Lock Type (see page
Lockstat Command Output – Statistics by Lock Type).
Here is sample output from the Statistics section:
========Fri Apr 13 13:34:06 2010 Locking System Statistics======
Create lock list 49395 Release lock list 49327
Request lock 586295 Re-request lock 457810
Convert lock 68157 Release lock 410846
Escalate 10 Lock wait 27489
Convert wait 2 Convert Deadlock 1
Deadlock Wakeups 2218 Max dlk queue len 10
Deadlock Search 1947 Deadlock 134
Cancel 135 Convert Search 2
Allocate CB 1161478 Deallocate CB 1160861
LBK Highwater 3 LLB Highwater 87
SBK Highwater 5 LKB Highwater 428
RBK Highwater 5 RSB Highwater 420
Max Local dlk srch 3 Dlk locks examined 2361
Max rsrc chain len 5 Max lock chain len 5
Callback Wakeups 0 Callbacks Invoked 0
Callbacks Ignored 0
Statistics by lock type:
Fields are as follows:
Create lock list
Number of times a lock list was created for server, session, or transaction
Release lock list
Number of times a release of a lock list occurred for a server, session, or transaction
Request lock
Number of new lock requests that the locking system processed
Re-request lock
Number of times an implicit lock conversion request was issued on a resource that the lock list already had locked. Implicit lock conversion requests can occur when a request is made on a page for update that was previously requested for read.
Convert lock
Number of times an explicit lock conversion request is made to change a lock mode on a physical lock from one mode to another. These types of requests occur as a result of a physical lock being converted during an existing transaction to lower or higher modes.
Release lock
Number of times a specific logical lock is released, as opposed to a full, partial, or physical lock release.
Escalate
Number of times a partial release occurred to allow lock escalation from page to table level
Lock wait
Number of times a new lock request had to wait to be granted
Convert wait
Number of times an existing lock waited for conversion to a different lock mode
Convert deadlock
Number of times a request for conversion turned into a deadlock
Deadlock Wakeups
Number of times the interval-based deadlock detection thread was awakened
Max dlk queue len
Maximum number of waiting lock lists examined by the deadlock detection thread
Deadlock search
Number of times a deadlock search was initiated
Deadlock
Number of times that deadlock existed
Cancel
Number of times a lock request was canceled due to a time-out or interrupt
Convert search
Number of times a convert deadlock search was initiated. The searches are performed when converting a lock from one mode to another.
Allocate CB
Number of locking control block allocations
Deallocate CB
Number of locking control block deallocations
LBK Highwater
Maximum number of lock list blocks allocated
LLB Highwater
Maximum number of lock lists allocated
SBK Highwater
Maximum number of lock blocks allocated
LKB Highwater
Maximum number of locks allocated
RBK Highwater
Maximum number of resource blocks allocated
RSB Highwater
Maximum number of resources allocated
Max Local dlk srch
Maximum number of locks examined to resolve
Dlk locks examined
Number of locks examined by the deadlock detection thread
Max rsrc chain len
Maximum length of a resource hash chain
Max lock chain len
Maximum length of a lock hash chain
The remaining fields are relevant only when the installation has been configured to run with the Distributed Multi-Cache Management (DMCM) protocol:
Callback Wakeups
Number of times the DMCM callback thread was awakened
Callbacks Invoked
Number of times callback functions were invoked to resolve a blocking cache lock
Callbacks Ignored
Number of blocking cache locks which had already been released by the time the callback function was invoked