Table 1. Resources for which INQUIRE
UOWENQ does not return information
Resource name
Type of resource
ISSSENQP
Sockets used by IPIC communication for an IPCONN.
JOURNALS
CICS journal names used during creation, deletion,
or use of a journal entry. See Log manager waits
for information to help you diagnose problems with the MVS system
logger.
KCADDR
Addresses locked internally by CICS.
KCSTRING
Strings locked internally by CICS.
LOGSTRMS
MVS logstream names used during connection
of streams to the MVS logger. A long wait could indicate a problem
with the logger. See Log manager waits for
information to help you diagnose problems with the MVS system
logger.
To investigate enqueue waits on these resources, you can use the
NQ section of a system dump. (You can use a system dump to investigate
enqueue waits on other types of resource, but you might find the INQUIRE
UOWENQ command more convenient.)
CICS maintains a separate enqueue pool for each type of resource
that can be enqueued upon. To produce a summary of each enqueue pool,
specify 1 on the NQ dump formatting keyword (dump
formatting keywords are described in Summary of system dump formatting keywords and levels). Figure 1 shows an example summary for the transient
data enqueue (TDNQ) pool. Figure 1. Example system dump,
showing summary information for the TDNQ enqueue pool
==NQ: ENQUEUE POOL SUMMARY - TDNQ
Default shunt action: Retain
*Total enqueue requests: 34
*Total requests that have waited: 8
*Total requests failed busy: 6
*Total requests failed locked: 2
*Total requests timed out: 1
*Total enqueues that were retained: 1
*NOTE: These values were reset at 15.44.39 (the last statistics interval collection)
OWNER / WAITER
NQEA Tran Tran Lifetime Hash
Enqueue Name Len Sta Address Id Num Local Uowid Uow Tsk Indx
------------------------------ --- --- -------- ---- ----- ---------------- --- --- ----
Q007TOQ 9 Act 052C4580 TDWR 00356 A8EBC70A53A4BC82 1 0 13
Q002FROMQ 9 Act 053D0880 TDRD 00435 A8EBD91A57D9B7D2 2 0 24
Waiter : 0540BBC0 TDRD 00467 A8EBDAC692BB7C10 0 1 24
Waiter : 0537CE70 TDDL 00512 A8EBDAE6FF0B56F2 1 0 24
Q007FROMQ 9 Act 0540CC80 ENQY 00217 A8EBB7FE23067C44 0 1 51
Waiter : 0538F320 ENQY 00265 A8EBBF0846C00FC0 0 1 51
Waiter : 0518C5C0 ENQY 00322 A8EBC393B90C66D8 0 1 51
Q002TOQ 9 Ret 0520B260 ---- ----- A8EBD82AFDA4CD82 1 0 53
Q009FROMQ 9 Act 0540A140 TDRD 00366 A8EBC84D3FF80250 1 0 62
In the table at the bottom of Figure 1,
each enqueue in the pool appears on a new line. If the enqueue has
waiters, they are displayed in order on subsequent lines. Waiters
are identified by the string Waiter. The meanings
of the table headings are:
Enqueue Name
The string that has been enqueued upon. Normally, up to 30 characters
of the name are displayed; however, the summary reports for file control
and address enqueue pools format the enqueue name differently:
File control uses six enqueue pools for its various types of lock.
Each enqueue contains the address of a control block (for example,
DSNB, FCTE) in its first four bytes. If the enqueue is a record lock, this
is followed by the record identifier.
Depending upon the type
of the data set or file, the remainder of the enqueue name could,
for example, be an RRN in an RRDS, or a record key in a KSDS data set.
In the summary, the remainder of the enqueue name is displayed in
both hex and character formats. This takes up two summary lines instead
of one.
The summary reports for the EXECADDR and KCADDR enqueue pools
display the enqueue name in hexadecimal format. This is because the
enqueue request was made on an address.
IPIC communication can use more than one socket for
an IPCONN when communicating with another system.
For each of these sockets, there is an IPIC session set (ISSS) control
block and an associated enqueue name.
The enqueue name is a character string
that is composed of the first four characters of the IPCONN name followed
by ‘ISSSnnnx’ where nnn is
an index for a particular IPIC session set (ISSS) and x is
the character S or C.
Len
The length of the enqueue name.
Sta
The state that the enqueue is held in. This field contains either:
Act
The enqueue is held in active state—that is, other transactions
are allowed to wait on the enqueue.
Ret
The enqueue is held in retained state—that is, other transactions
are not allowed to wait on the enqueue. Typically, this is because
the enqueue is owned by a shunted unit of work.
NQEA Address
The address of the NQEA corresponding to the enqueue owner or
waiter. The NQEA contains the full enqueue name if it was too large
to display fully.
TranId
The transaction identifier of the enqueue owner or waiter. If
the enqueue is owned by a shunted UOW, this field contains '----'.
TranNum
The task number of the enqueue owner or waiter. If the enqueue
is owned by a shunted UOW, this field contains '-----'.
Local Uowid
The local UOW identifier of the enqueue owner or waiter.
Uow Lifetime
For an enqueue owner, the number of times the enqueue is owned
with UOW lifetime. For an enqueue waiter, whether the waiter has requested
the enqueue for the lifetime of the UOW.
Tsk Lifetime
For an enqueue owner, the number of times the enqueue is owned
with task lifetime. For an enqueue waiter, whether the waiter has requested
the enqueue for the lifetime of the task.