Re: held locks after exit

["Benoit Donnette" <bdonnette@linagora.com>]

Well, you've highlighted 4 unreleased locks, a solution quite like using a
sledgehammer to crack a nut but predictably efficient would be to
backtrace() every lock and unlock so as to match them and to identify
which locks haven't been released (but your traces show enough detail to
help us focus the watch on specific db4 code).

If this can help.

> After an otherwise "clean" exit of test058, the smc/db directory showed
> the following, despite the fact that there was no more 9196 pid on the
> system. Is there any facility in db4 to trace locking?
>
> I don't think slapd's own debugging would give the level of detail that
> would be necessary to find a smoking gun, but if I'm just reading stuff
> wrong, I have the testrun directory from this.
>
> ---------- begin output ----------
>
> Default locking region information:
> 138	Last allocated locker ID
> 0x7fffffff	Current maximum unused locker ID
> 9	Number of lock modes
> 1000	Maximum number of locks possible
> 1000	Maximum number of lockers possible
> 1000	Maximum number of lock objects possible
> 20	Number of lock object partitions
> 4	Number of current locks
> 12	Maximum number of locks at any one time
> 3	Maximum number of locks in any one bucket
> 0	Maximum number of locks stolen by for an empty partition
> 0	Maximum number of locks stolen for any one partition
> 9	Number of current lockers
> 15	Maximum number of lockers at any one time
> 4	Number of current lock objects
> 8	Maximum number of lock objects at any one time
> 2	Maximum number of lock objects in any one bucket
> 0	Maximum number of objects stolen by for an empty partition
> 0	Maximum number of objects stolen for any one partition
> 1009	Total number of locks requested
> 1005	Total number of locks released
> 0	Total number of locks upgraded
> 46	Total number of locks downgraded
> 4	Lock requests not available due to conflicts, for which we waited
> 0	Lock requests not available due to conflicts, for which we did not wait
> 0	Number of deadlocks
> 0	Lock timeout value
> 0	Number of locks that have timed out
> 0	Transaction timeout value
> 0	Number of transactions that have timed out
> 488KB	The size of the lock region
> 4	The number of partition locks that required waiting (0%)
> 4	The maximum number of times any partition lock was waited for (0%)
> 0	The number of object queue operations that required waiting (0%)
> 1	The number of locker allocations that required waiting (0%)
> 0	The number of region locks that required waiting (0%)
> 2	Maximum hash bucket length
> =-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=
> Lock REGINFO information:
> Lock	Region type
> 5	Region ID
> __db.005	Region name
> 0xfecf0000	Original region address
> 0xfecf0000	Region address
> 0xfecf00c8	Region primary address
> 0	Region maximum allocation
> 0	Region allocated
> Region allocations: 3006 allocations, 0 failures, 0 frees, 1 longest
> Allocations by power-of-two sizes:
>    1KB	3003
>    2KB	0
>    4KB	0
>    8KB	0
>   16KB	2
>   32KB	0
>   64KB	1
> 128KB	0
> 256KB	0
> 512KB	0
> 1024KB	0
> REGION_JOIN_OK	Region flags
> =-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=
> Lock region parameters:
> 104	Lock region region mutex [0/119 0% 11775/1]
> 1031	locker table size
> 1031	object table size
> 616	obj_off
> 63456	locker_off
> 0	need_dd
> =-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=
> Lock conflict matrix:
> 0	0	0	0	0	0	0	0	0
> 0	0	1	0	1	0	1	0	1
> 0	1	1	1	1	1	1	1	1
> 0	0	0	0	0	0	0	0	0
> 0	1	1	0	0	0	0	1	1
> 0	0	1	0	0	0	0	0	1
> 0	1	1	0	0	0	0	1	1
> 0	0	1	0	1	0	1	0	0
> 0	1	1	0	1	1	1	0	1
> =-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=
> Locks grouped by lockers:
> Locker   Mode      Count Status  ----------------- Object ---------------
>        85 dd= 0 locks held 1    write locks 0    pid/thread 9196/1
>        85 READ          1 HELD    id2entry.bdb              handle
> 0
>        86 dd= 0 locks held 0    write locks 0    pid/thread 9196/1
>        87 dd= 0 locks held 1    write locks 0    pid/thread 9196/1
>        87 READ          1 HELD    dn2id.bdb                 handle
> 0
>        88 dd= 0 locks held 0    write locks 0    pid/thread 9196/1
>        89 dd= 0 locks held 0    write locks 0    pid/thread 9196/1
>        8a dd= 0 locks held 0    write locks 0    pid/thread 9196/1
> 8000013c dd= 0 locks held 0    write locks 0    pid/thread 9196/1
> 8000013d dd= 0 locks held 0    write locks 0    pid/thread 9196/1
> 80000145 dd= 0 locks held 2    write locks 2    pid/thread 9196/1
> 80000145 WRITE         1 HELD    0x39548 len:   5 data: 0000000x0100
> 80000145 WRITE         1 HELD    id2entry.bdb              page          1
> =-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=
> Locks grouped by object:
> Locker   Mode      Count Status  ----------------- Object ---------------
> 80000145 WRITE         1 HELD    0x39548 len:   5 data: 0000000x0100
>
> 80000145 WRITE         1 HELD    id2entry.bdb              page          1
>
>        85 READ          1 HELD    id2entry.bdb              handle
> 0
>
>        87 READ          1 HELD    dn2id.bdb                 handle
> 0
>
>
>
>