-DISPLAY DDF command (Db2)

The DISPLAY DDF command output includes the status and configuration of DDF for the local subsystem or member. It also includes statistics for the connections and threads that are controlled by DDF.

csect-name

The name of the control section that issued the message.

The introduction to the output is followed by the operational status of DDF:

DSNL081I STATUS=status

status

The DDF status, which can be one of the following values:

STARTD

DDF is started.

STARTG

DDF is starting.

STOPDF

DDF was stopped abnormally, for example, by the STOP DDF command with the MODE(FORCE) option.

STOPDQ

DDF was stopped normally or is not yet started. DDF can be stopped normally by using the STOP DDF command with the MODE(QUIESCE) option.

STOPGF

DDF is in the process of stopping abnormally, for example, by the STOP DDF command with the MODE(FORCE) option.

STOPGQ

DDF is in the process of stopping normally, for example, by the STOP DDF command with the MODE(QUIESCE) option

SUSPND

DDF is suspended, for example, by the STOP DDF command with the MODE(SUSPEND) option.

SUSPNG

DDF is in the process of suspending, for example, by the STOP DDF command with the MODE(SUSPEND) option.

NOINIT

DDF is not configured. The value of the DDF subsystem parameter is NO.

Related information

• -STOP DDF command (Db2)
• DDF STARTUP OPTION field (DDF subsystem parameter)

The DDF status information is followed by location information:

DSNL082I LOCATION           LUNAME            GENERICLU
DSNL083I location           luname            genericlu

location

The location name of DDF, as recorded in the bootstrap data set (BSDS). The location name can be specified by one of the following methods:

• The Db2 LOCATION NAME field on the DSNTIPR installation panel
• The LOCATION option in the DDF statement of the DSNJU003 (change log inventory) utility

luname

The DDF LU name, as recorded in the BSDS. The LU name can be specified by one of the following methods:

• The Db2 NETWORK LUNAME field on the DSNTIPR installation panel
• The LUNAME option in the DDF statement of the DSNJU003 (change log inventory) utility

A value of -NONE indicates one of the following situations:

• An LU name is not configured.
• The DDF record in the BSDS already has a value for IPNAME. Therefore, DDF did not activate its Systems Network Architecture (SNA) or Advanced Program to Program Communication (APPC) support.

If an LU name is configured, the luname field contains the fully qualified LU name, which consists of a network ID, a period delimiter, and the LU name. The network ID is determined from VTAM® after DDF is started. A network ID of NONE indicates that DDF is not yet started, or initialization with VTAM failed.

genericlu

The DDF generic LU name, as recorded in the BSDS. The generic LU name can be specified by one of the following methods:

• The Db2 GENERIC LUNAME field on the DSNTIPR installation panel
• The GENERIC option in the DDF statement of the DSNJU003 (change log inventory) utility

A value of -NONE indicates one of the following situations:

• A generic LU name is not configured.
• The DDF record in the BSDS already has a value for IPNAME. Therefore, DDF did not activate its Systems Network Architecture (SNA) or Advanced Program to Program Communication (APPC) support.

If a generic LU name is configured and enabled, the genericlu field contains the fully qualified generic LU name, which consists of a network ID, a period delimiter, and the generic LU name. The network ID is determined from VTAM after DDF is started. A network ID of NONE indicates that the DDF is not yet started, or initialization with VTAM failed.

The location name, LU name, and generic LU name for DDF are also included in message DSNL004I when DDF is started.

Related information

• DB2 LOCATION NAME field
• VTAM LUNAME
• DB2 GENERIC LUNAME field
• DSNJU003 (change log inventory)
• DSNL004I

The location information is followed by information about the TCP/IP port that is associated with DDF:

DSNL084I TCPPORT=tcp-port SECPORT=secure-port RESPORT=resync-port IPNAME=ip-name

tcp-port

The TCP/IP port number for the SQL listener, as recorded in the BSDS. This port number can be specified by one of the following methods:

• The DRDA PORT field on the DSNTIP5 installation panel
• The PORT option in the DDF statement of the DSNJU003 (change log inventory) utility

A value of 0 (zero) indicates that an SQL listener port was not specified, and DDF is not configured to use TCP/IP network protocols.

A value of -NONE indicates that Db2 does not accept connections on this port. One possible reason that Db2 does not accept connections is that the MAXDBAT subsystem parameter is set to 0 (zero). The current MAXDBAT value is listed in the DSNL090I message, which is included as part of the DISPLAY DDF output when the DETAIL option is specified.

secure-port

The TCP/IP port number for the secure SQL listener, as recorded in the BSDS. This port number can be specified by one of the following methods:

• The SECURE PORT field on the DSNTIP5 installation panel
• The SECPORT option in the DDF statement of the DSNJU003 (change log inventory) utility

A value of 0 (zero) indicates both of the following conditions:

• A secure SQL listener port was not specified.
• DDF is not configured to accept secure inbound connections by using the Secure Socket Layer (SSL) protocol through this port number.

If a secure port is not specified, remote connections can still use the TCP/IP port for the SQL listener (tcp-port) and use the SSL protocol on that port. However, DDF does not validate whether the connection uses SSL protocol.

A value of -NONE indicates that Db2 does not accept connections on this port. One possible reason that Db2 does not accept connections is that the MAXDBAT subsystem parameter is set to 0 (zero). The current MAXDBAT value is listed in the DSNL090I message, which is included as part of the DISPLAY DDF output when the DETAIL option is specified.

resync-port

The TCP/IP port number for the two-phase commit resynchronization (resync) listener, as recorded in the BSDS. This port number can be specified by one of the following methods:

• The RESYNC PORT field on the DSNTIP5 installation panel
• The RESPORT option in the DDF statement of the DSNJU003 (change log inventory) utility

A value of 0 (zero) indicates that a resynchronization listener port was not specified, and DDF is not configured to use TCP/IP network protocols.

ip-name

The IPNAME value, as recorded in the BSDS. For a description of the IPNAME value, see the DSNJU003 syntax information.

This value is unique to this DDF.

If this Db2 subsystem is a member of a data sharing group, the IPNAME value is unique to that data sharing group. If all the members of a data sharing group activate only their TCP/IP communications support, all members of that group must be defined with the same IPNAME value.

This TCP/IP port information for DDF is also included in message DSNL004I, which is displayed when DDF is started.

Related information

• TCPIP PORT
• SECURE PORT field
• RESYNC PORT field
• MAX REMOTE ACTIVE field (MAXDBAT subsystem parameter)
• DSNL004I
• DSNJU003 (change log inventory)

The TCP/IP port information is followed by the IP address that is associated with DDF:

DSNL085I IPADDR=ip-address

ip-address

The IP address of DDF.

If the subsystem is a member of a data-sharing group, the IP address is a sysplex-wide IP address. Db2 expects this sysplex-wide IP address to be configured as a distributed dynamic virtual IP address (distributed DVIPA). A distributed DVIPA distributes connections across the group.

A value of -NONE indicates that one or more of the following conditions is true:

• DDF is not configured to use TCP/IP network protocols. See the tcp-port value in message DSNL084I.
• DDF is not started.
• TCP/IP initialization failed.

If both IPv4 and IPv6 addresses are configured, message DSNL085I is displayed twice, once for each protocol type.

If the subsystem is not a member of a data sharing group and the listener ports are defined, DDF obtains its IP address from one of the following places:

• The IP address that is recorded in the BSDS
• The information that is returned by a z/OS UNIX System Services getaddrinfo call

If the subsystem is a member of a data sharing group and the listener ports are defined, DDF obtains the location's sysplex-wide IP address from one of the following places:

• The IP address that is recorded in the BSDS
• The IP address that is bound in the TCP/IP PORT definition statement for the DRDA SQL port

If the IP address is recorded in the BSDS, DDF accepts connections on any address. Otherwise, DDF accepts connections on only the IP addresses that are displayed in messages DSNL085I and DSNL089I.

Related information

• Communicating with data sharing groups
• getaddrinfo (BPX1GAI, BPX4GAI) -- Get the IP address and information for a service name or location
• Starting TCP/IP support

The IP address is followed by the TCP/IP domain name that is associated with DDF:

DSNL086I domain-type DOMAIN=domain-name

domain-type

The type of domain name that is displayed, which can be one of the following values:

SQL

The name that is used by TCP/IP to route requests to the location. The name is associated with the IP address that is displayed in message DSNL085I.

RESYNC

The name that is used by TCP/IP to route requests to DDF. This information is displayed only if DDF is a member of a Db2 data sharing group. This name is associated with the IP address that is displayed in message DSNL089I.

domain-name

The domain name that is associated with the domain type. A value of -NONE indicates that TCP/IP is not configured or that TCP/IP initialization failed.

This domain information is also included in messages DSNL519I and DSNL004I.

Related information

• DSNL519I
• DSNL004I
• Communicating with data sharing groups

If aliases were defined for the DDF location by using the MODIFY DDF command or by using the DSNJU003 (change log inventory) utility, the output includes alias information:

DSNL087I ALIAS           PORT     SECPORT     STATUS
DSNL088I alias           port     secure-port status

alias

An alias name.

You can manage static aliases by using the DSNJU003 (change log inventory) utility. You can manage dynamic aliases by using the MODIFY DDF command and specifying the ALIAS option.

port

The TCP/IP port that is associated with the alias. A 0 (zero) value indicates that a port was not specified for the alias. However, the alias can still be accessed by using other active DRDA SQL ports.

This value is ignored for statically defined location aliases in non-data-sharing environments.

secure-port

The TCP/IP secure port that is associated with the alias. A 0 (zero) value indicates that a secure port was not specified for the alias. However, the alias can still be accessed by using other active DRDA secure SQL ports.

This value is ignored for statically defined location aliases in non-data-sharing environments.

status

The operational status of the alias, which can be one the following values:

STARTG

The alias is starting. The MODIFY DDF command was issued with the ALIAS keyword to start the alias, and the start operation is in progress.

STARTD

The alias is started or ready to start with the alias port. Db2 might be processing existing connections to the alias and is accepting new connection requests to the alias by using the alias port. Otherwise, Db2 starts accepting new connection requests to the alias by using the alias port when the following conditions become true:

• DDF is started.
• The MAXDBAT subsystem parameter is set to a value greater than 0.

STOPG

The alias is stopping. The MODIFY DDF command with the ALIAS keyword was issued to stop an alias, and the stop operation is in progress.

STOPD

The alias is stopped. Db2 does not accept new connection requests to the alias by using the alias port. However, Db2 can still accept requests to the alias by using the group SQL port if DDF is active and listening on it. This value applies to only those aliases that are defined and managed dynamically by the MODIFY DDF command with the ALIAS keyword.

CANCLG

The alias is canceling. The MODIFY DDF command with the ALIAS keyword was issued to cancel an alias, and the cancel operation is in progress.

CANCLD

The alias is canceled. Db2 canceled all existing database access threads (DBATs) that were processing connections to the alias. Db2 does not accept new connection requests to the alias by using the alias port. However, Db2 can still accept requests to the alias by using the group SQL port if DDF is active and listening on it. This value applies to only those aliases that are defined and managed dynamically by the MODIFY DDF command with the ALIAS keyword.

STATIC

The alias is static. Db2 accepts new connection requests when Db2 is available to accept TCP/IP connection requests. This option applies to only those aliases that were created by the DSNJU003 utility. Such aliases cannot be defined or managed dynamically by the MODIFY DDF command.

Related information

• -MODIFY DDF command (Db2)
• DSNJU003 (change log inventory)
• MAX REMOTE ACTIVE field (MAXDBAT subsystem parameter)

If DDF is part of a data sharing group and all of the following conditions are true, the member IP address is displayed:

• DDF is configured to use TCP/IP network protocols. See the tcp-port value in message DSNL084I.
• DDF is started.
• TCP/IP initialization was successful.

DSNL089I MEMBER IPADDR= ip-address 

ip-address

The IP address that is associated with the specific member of the group or with a specific location alias that represents a member or subset of members. This value is the IP address that is returned to a client in the server list for the purposes of workload balancing.

If both IPv4 and IPv6 addresses are configured, message DSNL089I is displayed twice, once for each protocol type.

DDF obtains its member IP address from one of the following places:

• The IP address that is specified on the TCP/IP PORT statement by using the BIND keyword
• The IP address that is recorded in the BSDS
• The information that is returned by a z/OS UNIX System Services getaddrinfo call

Related information

• Communicating with data sharing groups
• getaddrinfo (BPX1GAI, BPX4GAI) -- Get the IP address and information for a service name or location
• Starting TCP/IP support

If the DETAIL option was specified on the DISPLAY DDF command, the output also includes subsystem parameter information that is associated with DDF:

DSNL090I DT=dt  CONDBAT=     condbat MDBAT=   mdbat

dt

The DDF threads value. This value corresponds to the CMTSTAT subsystem parameter.

Deprecated function: The CMTSTAT subsystem parameter is deprecated, which means that it might be removed eventually. Set the CMTSTAT value to INACTIVE. Although, the ACTIVE setting can sometimes provide limited CPU performance advantages, they are generally outweighed by increased use of other system resources and the lack of scalability for distributed application workloads. For the recommended alternatives to the ACTIVE setting, see Enabling KEEPDYNAMIC refresh for DBATs and Enabling high-performance DBATs.

dt can have one of the following values:

A

DDF is configured with DDF THREADS ACTIVE.

I

DDF is configured with DDF THREADS INACTIVE.

condbat

The maximum number of inbound connections. This value corresponds to the CONDBAT subsystem parameter.

mdbat

The maximum number of database access threads (DBATs). This value corresponds to the MAXDBAT subsystem parameter.

This value determines the maximum number of active slots, which means the maximum number of concurrent active DBATs that can potentially execute SQL.

Related information

• DDF THREADS field (CMTSTAT subsystem parameter)
• MAX REMOTE CONNECTED field (CONDBAT subsystem parameter)
• MAX REMOTE ACTIVE field (MAXDBAT subsystem parameter)

If the DETAIL option was specified on the DISPLAY DDF command, the output also includes subsystem parameter information that is associated with DDF:

DSNL091I MCONQN=maxconqn-value MCONQW=maxconqw-value

maxconqn-value

The depth of the queue of connections that are waiting for a DBAT to process the next request. When this value is reached, and the threshold that is specified by the MAXDBAT subsystem parameter is also reached, Db2 closes the oldest waiting client connection.

This value corresponds to the MAXCONQN subsystem parameter.

maxconqw-value

The maximum amount of time that a client connection waits for a thread to process its request. Db2 attempts to close any connection that waits longer than this value.

This value corresponds to the MAXCONQW subsystem parameter.

Related information

• CONN QUEUE MAX DEPTH field (MAXCONQN subsystem parameter)
• CONN QUEUE MAX WAIT field (MAXCONQW subsystem parameter)
• MAX REMOTE ACTIVE field (MAXDBAT subsystem parameter)

If the DETAIL option was specified on the DISPLAY DDF command, the output also includes the following information:

• The number of active, inactive, queued, and disconnected database access threads (DBATs)
• The number of queued and inactive connections

DSNL092I ADBAT=adbat QUEDBAT=quedbat INADBAT=inadbat CONQUED=conqued
DSNL093I DSCDBAT=dscdbat INACONN=inaconn IUDBAT=iudbat

adbat

The current number of DBATs. This number includes DBATs that are actively associated with work for remote connections and disconnected DBATs.

This value increases as new DBATs are created or when inactive DBATs become active. This value decreases as DBATs terminate or become inactive or as disconnected DBATs terminate. When this value reaches or exceeds the MAXDBAT value, newly attached connections or new work on existing inactive connections or threads might be queued. This queueing occurs if no disconnected DBATs are available to service the work.

The MAXDBAT value is shown in message DSNL090I.

quedbat

The cumulative number of the following new work items that had to wait for a DBAT to become available:

• Newly attached connections
• New work on inactive connections
• New work on inactive DBATs
• New or existing work is suspended because it exceeded the exception threshold for the MONITOR THREADS keyword in a monitor profile.

This value is a cumulative counter that is incremented for one of the following reasons:

• The MAXDBAT limit is reached.
• An exception threshold for the MONITOR THREADS keyword in the DSN_PROFILE_ATTRIBUTES table was exceeded. That exception threshold limits the concurrent number of DBATs for certain connections.

This value corresponds to the QDSTQDBT field in IFCID 1. The quedbat counter is reset only when this Db2 subsystem is restarted.

A non-zero value suggests that performance and throughput might be affected. If so, consider increasing the MAXDBAT value.

The MAXDBAT value is shown in message DSNL090I.

inadbat

The current number of inactive DBATs (which were previously called type 1 inactive threads). This value applies only if the dt value in message DSNL090I indicates that DDF INACTIVE support is enabled.

For more information about any DBATs that are included in this number, look at the output from the DISPLAY THREAD command with the TYPE(INACTIVE) option. The DISPLAY THREAD output begins with message DSNV401I.

conqued

The current number of connection requests that are queued and are waiting to be serviced. This value applies only if the dt value in message DSNL090I indicates that DDF INACTIVE support is enabled.

These connections can be newly attached connections or inactive connections for which a new request arrived from the client. The number of inactive connections is shown in message DSNL093I.

These requests cannot be processed when one of the following conditions occur:

• The maximum number of DBATs is reached, and no disconnected DBATs exist to process the request.

  The maximum number of threads is reached when the adbat value is equal to or greater than MAXDBAT value. (The MAXDBAT value is shown in message DSNL090I.) When this situation occurs, processing continues for these queued connections when another active DBAT releases its slot either by terminating or by moving to the inactive state.

• An exception threshold will be exceeded for the MONITOR THREADS keyword in the DSN_PROFILE_ATTRIBUTES table if the connection request is processed.
• DDF is suspended or suspending. See the status value in message DSNL081I. Processing continues when DDF is started.

dscdbat

The current number of disconnected DBATs. This value applies only if the dt value in message DSNL090I indicates that DDF INACTIVE support is enabled.

This value indicates the number of DBAT pool threads. DBAT pool threads are the database access threads that are available to service queued connections requests. The DBATs that are included in this number are also accounted for in the adbat value.

Over time, disconnected DBATs can hold allocation duration locks. An allocation duration lock is a lock that persists across commit boundaries. This type of lock requires the connection to be deallocated or the thread to be enabled if it is inactive. You can release these allocation duration locks by terminating these DBATs. You can terminate disconnected DBATs by using one of the following methods:

• Issue the STOP DDF command with the MODE(SUSPEND) option. Stopping DDF with MODE(SUSPEND) terminates these disconnected DBATs without affecting current or new connections. However, activity on these current or new connections is not processed until DDF is started.
• Change the value of the POOLINAC subsystem parameter. This parameter controls the length of time after which unused disconnected DBATs are to be automatically terminated.

inaconn

The current number of inactive connections (which were previously called type 2 connections). This value applies only if the dt value in message DSNL090I indicates that DDF INACTIVE support is enabled.

This value represents connections with clients where the client last ended a unit of work either by a commit or rollback operation. This operation caused Db2 to change the state of the connection to inactive, which means that the DBAT is separated from the connection. The connection becomes inactive while the DBAT is made available to service new client connections or to service new requests on existing client connections.

This value is not included in the inadbat value. When a new request arrives from the client system on the connection, the connection is then moved to the conqued value.

For more information about any connections that are included in this number, look at the output from the DISPLAY THREAD command with the TYPE(INACTIVE) option. The DISPLAY THREAD output begins with message DSNV401I.

iudbat

The current number of DBATs that are in use and processing client requests. This value applies only if the dt value in message DSNL090I indicates that DDF INACTIVE support is enabled

This value represents the difference between the adbat and dscdbat values.

Related information

• POOL THREAD TIMEOUT field (POOLINAC subsystem parameter)
• -DISPLAY THREAD command (Db2)
• -STOP DDF command (Db2)
• DSNV401I

The output also includes information about connections that were closed if both of the following conditions are true:

• The DETAIL option was specified on the DISPLAY DDF command
• The Db2 subsystem is a member of a data sharing group

DSNL094I WLMHEALTH=health-value CLSDCONQN=number-closed CLSDCONQW=wait-closed

health-value

The health indicator value that was last reported to WLM for the Db2 subsystem. This value is a number from 0 to 100.

number-closed

The number of client connections that were closed because the value of the MAXCONQN subsystem parameter was reached since DDF was last started.

wait-closed

The number of client connections that were closed because the value of the MAXCONQW subsystem parameter was reached since DDF was last started.

Related information

• IWM4HLTH – Setting Server Health Indicator
• CONN QUEUE MAX DEPTH field (MAXCONQN subsystem parameter)
• CONN QUEUE MAX WAIT field (MAXCONQW subsystem parameter)

If the ALIAS and DETAIL options were specified on the DISPLAY DDF command, the output also includes detailed information about the specific location alias:

DSNL096I  ADBAT=active-dbats CONQUED=concurrent-queued TCONS=total-connections

active-dbats

The number of active DBATs that are currently processing requests on behalf of the specified alias.

concurrent-queued

The number of connection requests that are currently queued and waiting to be serviced on behalf of the specified alias.

total-connections

The total number of remote connections that are currently associated with the alias.

The output also includes server list information if the following conditions are true:

• The DETAIL option was specified on the DISPLAY DDF command
• DDF is part of a data sharing group
• DDF is configured to use TCP/IP (If the value of tcp-port in message DSNL084I is NONE, DDF is not configured to use TCP/IP.)

The following server list entry information is displayed for each DDF location or alias that registered to WLM as part of the data sharing group:

DSNL100I  LOCATION SERVER LIST: 
DSNL101I  WT     IPADDR       IPADDR
DSNL102I  weight ipv4-address ipv6-address

Message DSNL102I is repeated for each server list entry.

The server list information is provided to remote clients that are balancing the sysplex workload. The server list information might represent a single member of the data sharing group or a location alias that represents either a single member or a subset of members. This information influences which DDF is sent future work. DDF responds with an updated server list when DDF generates the response to a connection request or a connection reuse request.

weight

The WLM weight for the DDF location or location alias that is identified by the IP addresses. If no value is displayed, WLM indicates that DDF has no capacity and the entry is not included in the server list that is provided to the remote clients.

ipv4-address

The IPv4 address that is used to identify a DDF location or location alias that is registered to WLM. The address is in colon-hexadecimal format. If no IPv4 address is configured, this IP address is not displayed.

ipv6-address

The IPv6 address that is used to identify a DDF location or location alias that is registered to WLM. The address is in colon-hexadecimal format. If no IPv6 address is configured, this IP address is not displayed.

For more information, see .Communicating with data sharing groups

The output also includes a list of the DDF option values:

DSNL105I  CURRENT DDF OPTIONS ARE: 
DSNL106I  option-name = option-value

One instance of message DSNL106I is displayed for each option.

option-name

The DDF option.

option-value

The value of the DDF option.

The DISPLAY GROUP command output includes a DSNL106I message for the ACCTG value of option-name only if the ACCTG(ALLCOMMIT) setting is in effect.

The DISPLAY DDF output ends with the following message:

DSNL099I  csect  DISPLAY DDF REPORT COMPLETE 

csect-name

The name of the control section that issued the message.