You can use the DSNWDMP statement to specify the dump records
to be used as input, and causes the Db2 dump
formatter (DSNWDPRD) to be invoked, which formats the specified Db2 control blocks.
Format the Db2 control
blocks in a dump by changing the parameters on the DSNWDMP control
statement. The format of this control statement and the options that
can be specified are shown in the following diagram.
ds-options:
sm-options:
st-options:
dm-options:
bm-options:
sh-options:
db-options:
et-options:
di-options:
disys-options:
rs-options:
sp-options:
sq-options:
lo-options:
rm-options:
Separate multiple operands by commas, not blanks. A blank
that follows any operand in the control statement terminates the operand
list, and any subsequent operands are ignored. The following table
lists and explains each of the various keywords that can be specified
in the Db2 control statement
for formatting dumps.
Table 1. Keywords to format SVC dumps that are issued by Db2
Keyword
Explanation
SUBSYS= nnnn
Specifies the site-defined Db2 subsystem name (nnnn).
Range is one to four characters.
If TT is specified without a suboption, format the global trace
table.
If TT=1, display summary lines.
If TT=2, display the TT=1 information, as well as data items.
If TT=3, and DS is also specified, filter information by EB.
AA
Formats significant Db2 control
blocks in all active address spaces for the subsystem.
SA
Formats significant Db2 control
blocks that are associated with a single address space. The control
statement must designate the ASID in hexadecimal (up to four digits).
Apostrophes and leading zeros can be included or omitted (as in DE,
00DE, or '00DE').
LG
Formats a long form of the significant Db2 global control block structures.
Includes all resource manager-specific global information as well
as the system-wide global control blocks.
ALL
Formats all significant Db2 control blocks. Includes the trace table,
control blocks in global storage, and control blocks in all active
address spaces for the subsystem.
Equivalent to specifying TT,
AA, and LG.
SUMDUMP
Specifies the part of the dump data set to be used
as input to the dump formatter.
If SUMDUMP=YES, the input dump data is to be obtained from the
summary portion of the dump data set.
If SUMDUMP=NO, the input dump data is to be obtained from the
non-summary portion of the dump data set.
The DSNWDPRD dump formatter always tries to format the same
control blocks and data structures, regardless of whether input dump
data is obtained from the summary or non-summary portion of the dump
data set.
DS
Specifies the level of detail about agents to report.
If DS=1, display information about only those agents at thread
level that are on the allied agent chain are reported.
If DS=2, display information about all agents on the allied agent
chain are reported.
If DS=3, display information about the system agent chains, plus
all agents on the allied chain are reported. The system agent chains
are needed to obtain details of parallel tasks and DDF tasks.
If DS=4, in addition to the information for DS=3,
the LUWID (Logical Unit of Work ID), XID (Global Transaction ID),
user and accounting information to be displayed for each agent.
LM
Specifies information about IRLM to report.
If LM=1, report TRWA statistics.
If LM=2, if the agent is waiting for an IRLM request, report the
status of the last request.
If LM=3, list the held locks for every agent.
SM
Specifies information about Storage Manager to
report.
If SM=1, display the PHB chains from the GPVT. This information
gives an idea of global storage usage.
If SM=2, in addition to the information for SM=1, display the
SHB chains from each PHB.
If SM=3, display the information for SM=2 for every address space
that is connected to Db2.
If SM=4, in addition to the information for SM=3, display statistics
on the amounts of allocated and free storage in the variable pools.
If SM=5, in addition to the information for SM=4, display a sample
of allocated elements and attempt to determine the module that GETMAINed
the storage.
If SM=6, in addition to the information for SM=5, display free
elements.
PHB
Specifies a PHB address. If SM is specified, the
storage manager information is displayed only for the PHB with this
address.
ST
Specifies information about stack storage.
If ST=1, display the PSW, registers from the SDWA, and save area
trace the abending task, except for a console dump. If the DS option
is also specified, display the high-level SKB and stack storage usage.
If ST=2, in addition to the information for ST=1, display a formatted
save area trace for each stack. The DS option must also be specified.
If ST=3, and the DS option is also specified, in addition to the
information for ST=2, display a formatted display of stack storage.
SMSA
Specifies storage information for only the requested
ASID and for global storage.
DM
Specifies the Data Manager information to report:
If DM=1, format agent DMTR and LKTR traces.
If DM=2, in addition to the information for DM=1, display parent
lock and claim and drain information for agent.
BM
Specifies Buffer Manager information to report:
If BM=1, format agent BBTR trace.
If BM=2, in addition to the information for BM=1, display agent
BBRA information.
If BM=3, format all PBs and PB0. To restrict the amount of information
that is reported, you can filter by buffer pool, DBID, or OBID.
SH
Specifies data sharing information to report:
If SH=1, format agent BBTR trace.
If SH=2, in addition to the information for SH=1, display agent
BBRA information.
If SH=3, in addition to the information for SH=2, display agent
BBRA information.
If SH=4, in addition to the information for SH=3, display agent
BBRA information.
If SH=5, in addition to the information for SH=4, display agent
BBRA information.
DB
Specifies database descriptor information to report:
If DB=1, list the DBDs that are in memory. If DBID is also specified,
list information only for that DBID.
If DB=2, in addition to the information for DB=1, display DBD
section information.
If DB=3, in addition to the information for DB=2, display OBD
information.
If DB=4, format information for the specified DBID and OBID. The
DBID and OBID parameters are required.
If DB=5, in addition to the information for DB=4, display trigger
and referential constraint information. The DBID and OBID parameters
are required.
CT
Specifies the CT address for a specific agent.
Use this parameter with the DM or DB option to narrow the output to
a single agent.
ET
Specifies information about exception states:
If ET=1, list exception states.
If ET=2, in addition to the information for ET=1,
list LPL, GRECP, and WEPR information.
DI
Specifies information about DDF threads to report:
If DI=1, DDF DTM (Distributed Transaction Manager) related information
for the thread.
If DI=2, in addition to the information for DI=1, DDF DC (Data
Communications) related information for the thread.
DISYS
Specifies information about DDF system to report:
If DISYS=1, general DDF system-related information.
TOKEN
Specifies the TOKEN value for a specific thread
to be displayed. Use this option with the DI option and the DS=3 or
DS=4 option. A warning message is displayed if the TOKEN value is
invalid or no threads are associated with the specified TOKEN.
RS
Specifies
the Relational Data Services information to report:
If RS=1, display SQL statement and high-level Relational Data
Services information.
If RS=2, in addition to the information for RS=1, display more
detailed information, including plan and package information and SQLCA
information.
SP
Specifies the stored procedure information to report:
If SP=1, display stored procedure header information.
If SP=2, display run time information about WLM stored procedures.
If SP=3, display detailed information about the stored procedures, including trace information.
SQ
Specifies the status information to report on Db2 internal service tasks in the system services address space (ssnmMSTR), database services address space (ssnmDBM1), and DDF address space (ssnmDIST):
If SQ=1, display the current status of all service tasks.
If SQ=2, in addition to the SQ=1 information, display a list of waiters on the service task queue.
If SQ=3, in addition to the SQ=2 information, display latch information.
LO
Specifies the log manager information to format and report:
If LO=1, display BSDS information.
If LO=2, in addition to the LO=1 information, display active log data set information and active log pairs.
If LO=3, in addition to the LO=2 information, display archive log information.
If LO=4, in addition to the LO=3 information, display archive log reader information.
If LO=5, in addition to the LO=4 information, display log buffer information.
If LO=6, display physical log record information.
If LO=7, display logical log record information.
If LO=8, display help information.
RM
Specifies the resource manager vector table (RMVT) and resource manager function table (RMFT) information to format and report:
If RM=1, display RMVT information.
If RM=2, display RMFT information.
If RM=3, in addition to the RM=2 information, display RMFT information in compressed format.
If RM=4, in addition to the RM=2 information, display RMFT information in full format.
Use the following keyword default values:
If the SUBSYS keyword is specified with SUMDUMP=YES, the SUBSYS
keyword is used only if no summary records are found in the dump data
set. In this case, the SUBSYS keyword is used to locate significant Db2 control blocks within the non-summary
portion of the dump data set.
If none of the following operands are specified on a DSNWDMP control
card, the default is ALL.
AA SA LG
For each set of the following operands, the first operand overrides
the operands that follow it when all operands are used in the same
control statement. This behavior is because the first operand generates
formatted data that includes the formatted data that would be generated
by the operands that follow it.
ALL TT
ALL LG
ALL AA SA
For example, ALL overrides LG if
both operands are specified.
If the DS option is not specified, the output does not contain
formatted agent information.
SUMDUMP information
Because
the formatted control blocks consist of both volatile and static data,
input dump data selection should be based on the state of the control
blocks at a time that is as close as possible to the time of the error.
SUMDUMP=YES
For SVC dumps, the default is to use summary data records as input
to the dump formatter because the summary dump records contain volatile data
that was captured at a time close to the time of the error. Specifying
YES ensures that relevant Db2 diagnostic
information is sent.
SUMDUMP=NO
Because non-summary data is obtained asynchronously to the current
system activity when the dump is generated, volatile data might
have been altered or lost by the time it was placed into the dump
data set.
Use this option if errors occur when you gather dump data
or formatting the summary portion of the dump data set. Appropriate
error messages are issued in these circumstances. In addition, use
this option to format stand-alone or dynamic (z/OS® console) dumps.
DS information
Use the DS option to help
diagnose hangs and waits. The DS option gives you a snapshot of the
activity in Db2 at the time
the dump was taken.
The output that was generated when you specify the DS=1
option looks like the following.
Figure 1. Sample output from DSNWDMP
with DS=1 option
Status of the thread. This value is the same as
the ST and A fields in output from the command -DISPLAY THREAD.
3
Request count. This value is the same as the REQ
field in output from the command -DISPLAY THREAD.
4
The chain that the ACE is on. Possible values
are System Chain, Allied Chain, or Stored Proc.
5
Authorization ID associated with a signed-on connection.
This value is blank if no sign-on took place.
6
Plan name for the agent. This value is the same
as the PLAN field in output from the command -DISPLAY THREAD.
7
Correlation ID for the agent. This value is the
same as the ID field in output from the command -DISPLAY THREAD.
8
Correlation name for the agent.
9
Token that is associated with the thread. This
value is the same as the TOKEN field in output from the command -DISPLAY
THREAD.
10
Address of the execution block.
11
ASID of the primary address space.
12
ASID of the home address space.
13
Address of a spawned execution block, if there
is one.
14
The TCB address, if this is a TCB. This value
is zero if this is an SRB.
15
Whether the agent was suspended by Db2 at the time of the abend.
16
Value in Register 14 the last time that suspend
was requested. This value is valid only if the agent is suspended.
17
Timestamp when the suspend occurred.
Run DSNWDMP with option DS=1 or DS=2 to view allied threads
in Db2. Option DS=2 generates
information about all allied threads, while DS=1 generates only active
threads.
The following output is from DSNWDMP with option DS=2
after a Db2 hang at shutdown.
The details of the first ACE show that a CICS® thread was active at the time of the shutdown,
which is the reason for the hang.
Figure 2. Output from DSNWDMP with DS=2 option
after Db2 hangs at shutdown
Output from DS=3 shows both allied agents and system agents.
Option DS=3 is helpful for diagnosing problems in such areas as CPU
parallelism and the distributed data facility, where the tasks are
related to allied work but appear on the system ACE chain.
The
following output shows DSNWDMP with option DS=3 after a hang in a
parallel task.
Figure 3. Output from DSNWDMP with DS=3 for a
hang involving CPU parallelism
Use the LM option to diagnose
locking problems. The following output was obtained by running DSNWDMP
with options DS=1 and LM=3 to display information about held locks
for an agent at thread level: Figure 4. Output from DSNWDMP with
DS=1 and LM=3 for held lock information
ACE: 05419548 Status: T * Req: 0004 Allied Chain
Short: 7F298820
Authid: USRT001 Plan: TSTA85 Corrid: GT00XA85 Corrname: CICS41 Token: 00000003
EB Primary(Asid) Home(Asid) EBSPAWND TCB/SRB -Status-- R14
054195D8 VC1ADBM1(0067) CICS41F (001C) 00000000 005A9388 Suspended 85539590
IRLM statistics for ACE: 05419548
Suspend count - latch conflict: 0
Suspend count - other conflict: 0
Lock request count: 2
Unlock request count: 1
Query request count: 0
Change request count: 0
Other IRLM requests count: 0
P-Lock Lock requests: 0
P-Lock Change requests: 0
P-Lock Unlock requests: 0
Lock requests sent to XES : 0
Change requests sent to XES : 0
Unlock requests sent to XES : 0
Suspends due to IRLM Global contention : 0
Suspends due to XES Global contention : 0
Suspends due to false contention : 0
Requests denied due to retained lock : 0
Notify messages sent : 0
WU requested a LOCK at 03/21/1997 20:00:47.736272 for resource 0C0000020004001700000000 at state 3
with modify interest.
This is a local resource that is held on this subsystem.
This request is incompatible with a lock on this subsystem and the current states of this resource are:
The local resultant held state is 8
The local modify held state is 8
Resource 0C0000020001005F00000000 is held in state 02 and was granted at 03/21/1997 20:00:47.620534.
Resource 0C000004E3E2E3C1F8F54040 is held in state 04 and was granted at 03/21/1997 20:00:45.712241.
Work unit 0067009505419548 holds 00000002 resource locks.
SQ