Episode 2 DB2 pureScale Installation, Instance Management & Monitoring

DB2 pureScale
DB2 pureScale:
Installation & Instance Management
October 2010
Jessica Rockwood (jessicae@ca.ibm.com)
© 2010 IBM Corporation

Agenda
Easy installation of DB2 pureScale
Starting and stopping the pureScale cluster
Maintaining the pureScale cluster
– Managing the clustered file system
– Growing/shrinking the cluster
DB2 pureScale © 2010 IBM Corporation2
– Growing/shrinking the cluster
– System maintenance
Configuring the cluster caching facilities and buffer pools
Monitoring tools

A system meeting OS, hardware,
software and communications
requirements
– Standard OS image & pre-requisite
components
Typical DB2 ESE installation preparation
System A
/opt
/home/db2inst1
– Local (internal) storage for installation image
– Filesystems on external storage for database
– Ethernet network
– Instance and fenced userid
– Root access for installation
/db2autostoragepaths
/db2logs

Multiple systems meeting OS, hardware,
software and communications
requirements
– Standard OS image & pre-requisite
components
DB2 pureScale installation preparation
System B
/opt
/home/db2sdin1
System D
/opt
/home/db2sdin1
System C
/opt
/home/db2sdin1
System A
/opt
/home/db2sdin1
– Direct SAN connected disk storage with shared
disk space (for instance shared directory,
database data/logs, and tiebreaker disk)
– Ethernet and infiniband network
– Instance and fenced userid with same uid, gid,
home directory on all systems
– Root access for installation
– Ssh passwordless access for root userid
across all systems
/dev/hdisk1
/dev/hdisk2
/dev/hdisk3
…
/home/db2sdin1/home/db2sdin1

Installation & instance setup
DB2 pureScale installation will automatically install:
– DB2 pureScale feature
– Reliable scalable cluster technology (rsct)
– Tivoli System Automation for Multi Platform (SA MP)
– General Parallel File System (GPFS)
Instance setup will automatically:
– Create and configure GPFS cluster and instance shared filesystem on all hosts
– Create and configure SA MP peer domain on all hosts
– If required, create the instance user on all hosts
– Setup instance environment on all hosts ($HOME/sqllib)
– Setup ssh passwordless access between all hosts for the instance user
– Create DB2 pureScale instance and define cluster caching facilities (CFs) and
members

Installation & instance setup options
db2setup utility
– Launched from the install-initiating host (IIH) which is any system that
will be part of the DB2 pureScale cluster
– With a single invocation:
– Installs DB2 pureScale on all hosts in the cluster
– Creates the DB2 pureScale instance with all CFs and members
– Can be run either in GUI mode (as a wizard) or with a response file
– GUI: db2setup –l /tmp/db2setup.log –t
/tmp/db2setup.trc
– Response file: db2setup –r db2dsf.rsp –l
/tmp/db2setup.log –t /tmp/db2setup.trc

db2setup wizard – DB2 Cluster File System

db2setup wizard – Host List

Installation & instance setup options
Manual installation & instance creation
– db2_install utility needs to be run on the install-initiating host (IIH) to
install DB2 pureScale
db2_install –p ese_dsf –b /opt/IBM/db2/V9.8 –t
/tmp/db2_install.trc –l /tmp/db2_install.log
– Create the DB2 pureScale instance with the primary CF and first
– Create the DB2 pureScale instance with the primary CF and first
member (run from host 1 or host 2)
db2icrt –d –instance_shared_dev /dev/hdisk1 -tbdev
/dev/hdisk2 –cf host1:host1_ib -m host2:host2_ib
-u db2sdin1 db2sdin1
– Add the secondary CF
db2iupdt -add –cf host4:host4_ib –d db2sdin1
– Add additional members
db2iupdt –add –m host3:host3_ib –d db2sdin1

Starting and stopping DB2 pureScale
Starting the cluster
– Global DB2 pureScale start will start the CFs first and then the members
db2start
– Individual CF or member start
db2start [member] 0 or db2start [cf] 128
– Note: If starting a member and no CFs are started, the CFs will be started
– Note: If starting a member and no CFs are started, the CFs will be started
before the member is started
Stopping the cluster
– Global DB2 pureScale stop will stop the members first and the CFs
db2stop [force]
– Individual CF or member stop
db2stop [cf|member] [identifier] [force] [quiesce
[timeout_in_min]]

Instance and Host Status
Instance status
DB2 DB2
Single Database View
coralpib132 coralpib133
Clients
> db2start
08/24/2008 00:52:59 0 0 SQL1063N DB2START processing was successful.
08/24/2008 00:53:00 1 0 SQL1063N DB2START processing was successful.
SQL1063N DB2START processing was successful.
> db2instance -list
ID TYPE STATE HOME_HOST CURRENT_HOST ALERT
-- ---- ----- --------- ------------ -----
0 MEMBER STARTED coralpib132 coralpib132 NO
1 MEMBER STARTED coralpib133 coralpib133 NO
128 CF PRIMARY coralpib131 coralpib131 NO
0 coralpib132 0 coralpib132_ib0 - MEMBER
1 coralpib133 0 coralpib133_ib0 - MEMBER
128 coralpib131 0 coralpib131_ib0 - CF
db2nodes.cfg
Host status
CF
Shared Data
coralpib131 HOST_NAME STATE INSTANCE_STOPPED ALERT
--------- ----- ---------------- -----
coralpib131 ACTIVE NO NO
Shared Data

Automatic restart of members and CFs
If a member fails, the cluster services will automatically restart the
member
– If it cannot restart on its home host, cluster services will move the member to
another host for restart light
If a CF fails, the cluster services will automatically restart the CF
– If it is a primary CF that fails, the secondary CF will take over as primary as
– If it is a primary CF that fails, the secondary CF will take over as primary as
long as it was in Peer state
If cluster services cannot automatically restart a member or CF, it
will raise an alert
– Alert state is visible in ALERT column of ‘db2instance –list’ output
– Alerts can be viewed with ‘db2cluster –list –alert’ command
– Alerts must be cleared before cluster services can retry automatic restart using
‘db2cluster –clear –alert’

Managing the clustered file systems
Add disk to an existing filesystem (and optionally
rebalance)
db2cluster –cfs –add –filesystem db2fs1 –disk /dev/hdisk3
db2cluster –cfs –rebalance –filesystem db2fs1
Create a new clustered file system
db2cluster -cfs –create –filesystem db2fs2 –disk
/dev/hdisk3 –mount /db2_logs
Remove a filesystem and its disk
db2cluster -cfs –remove –filesystem db2fs2 –disk
/dev/hdisk3

Managing the clustered file systems
List clustered file systems
db2cluster -cfs -list –filesystem
FILE SYSTEM NAME MOUNT_POINT
-------------------------- -------------------------
db2fs1 /db2sd_20100223191453
List disks in a given clustered file system
db2cluster -cfs -list -filesystem db2fs1 –disk
PATH ON LOCAL HOST OTHER KNOWN PATHS
------------------------- -------------------------
(*) /dev/hdisk2

Growing/shrinking the DB2 pureScale cluster
A maximum of two CFs and 128 members can be
defined in a DB2 pureScale cluster
db2iupdt -add –cf host4:host4_ib db2sdin1
db2iupdt –add –m host3:host3_ib db2sdin1
To shrink the DB2 pureScale cluster by removing
members or removing the secondary CF
db2iupdt –drop –m host3 db2sdin1
db2iupdt –drop –cf host4 db2sdin1

System maintenance in DB2 pureScale
Stop the individual CF or member on the host where maintenance
will be applied
db2stop member 1 quiesce 1
– Note: If the primary CF is stopped, then the secondary CF will take over
Stop the instance on that same host to mark the host as unavailable
Stop the instance on that same host to mark the host as unavailable
for failover
db2stop instance on host3
Apply the system maintenance
Restart the instance on the host and restart DB2 on the host
db2start instance on host3
db2start member 1

Configuring cluster caching facilities (CF)
In the database manager configuration:
CF Server Configuration:
Memory size (4KB) (CF_MEM_SZ) = AUTOMATIC(158720)
Number of worker threads (CF_NUM_WORKERS) = AUTOMATIC(1)
Number of connections (CF_NUM_CONNS) = AUTOMATIC(14)
Diagnostic error capture level (CF_DIAGLEVEL) = 2
Diagnostic data directory path (CF_DIAGPATH) =
Diagnostic data directory path (CF_DIAGPATH) =
In the database configuration:
CF Resource Configuration:
CF database memory size (4KB) (CF_DB_MEM_SZ) = AUTOMATIC(4616448)
Group buffer pool size (4KB) (CF_GBP_SZ) = AUTOMATIC(3673856)
Global lock memory size (4KB) (CF_LOCK_SZ) = AUTOMATIC(692480)
Shared communication area size (4KB) (CF_SCA_SZ) = AUTOMATIC(248320)
Catchup target for secondary CF (mins)(CF_CATCHUP_TRGT) = AUTOMATIC(15)

Configuring buffer pools
Group buffer pool (GBP) is always sized in 4k pages, regardless of
local buffer pools (LBP) page size
– Note that the GBP by default has 20% of memory set aside for managing LBP
page registrations
GBP size is generally larger than a single LBP size
– Making LBP size too large can actually decrease GBP hit ratio, since each LBP
– Making LBP size too large can actually decrease GBP hit ratio, since each LBP
page consumes some GBP memory which can’t then be used for data pages
GBP size = 35-40% of (sum of all LBP sizes)
– e.g. LBP size = 1M 4k pages, 4 members => GBP = ~1.5M pages
– The heavier the write activity of the workload, the more modified pages the
GBP will contain, so the more benefit from a larger GBP.
– This RoT predominantly applies in clusters of 3 or members

Monitoring Overview
Expands on V97 monitoring functionality
Workload table functions – column and XML (_DETAILS suffix)
MON_GET_UNIT_OF_WORK & _DETAILS
MON_GET_CONNECTION & _DETAILS
MON_GET_WORKLOAD & _DETAILS
MON_GET_SERVICE_SUBCLASS & _DETAILS
MON_GET_PKG_CACHE_STMT & _DETAILS
MON_GET_ACTIVITY_DETAILS
Bufferpool table functions - column
Bufferpool table functions - column
MON_GET_TABLEPACE
MON_GET_BUFFERPOOL
Event monitors
Activity
Statistics
Package Cache
pureScale specific table functions
– MON_GET_CF
Useful summary views

Monitoring - Locking
pureScale-specific locking metrics for lock contention across members
Workload metrics
Available in the workload table functions and the event monitors
LOCK_WAITS_GLOBAL, LOCK_WAIT_TIME_GLOBAL
Number of and milliseconds spent in waits for locks held by applications on other members
Are component elements of the existing LOCK_WAITS and LOCK_WAIT_TIME elements
LOCK_TIMEOUTS_GLOBAL
Number of times a timeout occurred while waiting for a lock held by an application on another
Number of times a timeout occurred while waiting for a lock held by an application on another
member
LOCK_ESCALS_MAXLOCKS, LOCK_ESCALS_LOCKLIST, LOCK_ESCALS_GLOBAL
Number of lock escalations occurring due to exceeding the maxlocks, locklist, and cf_lock_sz
database configuration parameters, respectively.
All sum to equal the existing LOCK_ESCALS element
Locking event monitor
No new information, but adapted for cross-member lockwait and timeout events
MON_GET_APPL_LOCK, MON_GET_APPL_LOCKWAIT
Report on current locks on the system
Both adapted to work correctly in pureScale environments
no new columns

Monitoring – Database Objects
Global page statistics
Available in the workload table functions and the event monitor
reclaim_wait_time, spacemappage_reclaim_wait_time
Distinct values describing time spent performing page reclaims from other members.
A reclaim means a page has been updated by another member and must be refreshed on the local
member
A spacemap page is a special data page describing where other pages are located.
Cluster caching facility communication
Available in the workload table functions and the event monitor
cf_waits, cf_wait_time
The number of and milliseconds spent in communications with the Cfs.
Time is from when the connection is opened to when it is closed
Only includes time to send until acknowledgment of receipt, not time to fulfill any request (ie,
lock_wait_time_global)

Monitoring – Group Bufferpool
Monitoring of the group bufferpool activity
Independent of related local bufferpool metrics
Example: One POOL_DATA_L_READS will result in 0 or more POOL_DATA_GBP_L_READS
Workload metrics
Included in the workload and bufferpool table functions, and the event monitors
NOTE: XDA (ie, XML) elements are new for V98 FP3
POOL_DATA_GBP_L_READS, POOL_INDEX_GBP_L_READS, POOL_XDA_GBP_L_READS
Number of requests for the given page type from the group bufferpool (logical reads)
The page in the local bufferpool was either not present or invalid
POOL_DATA_GBP_P_READS, POOL_INDEX_GBP_P_READS, POOL_XDA_GBP_P_READS
Number of times a disk access was required due to the page not being present in the group bufferpool (physical reads)
Less than or equal to the the number of logical reads
POOL_DATA_LBP_PAGES_FOUND, POOL_DATA_LBP_PAGES_FOUND, POOL_DATA_LBP_PAGES_FOUND
Number of times a page was found in the local bufferpool, either valid or invalid.
Always less than or equal to the number of logical reads.
Example: POOL_DATA_LBP_PAGES_FOUND <= POOL_DATA_L_READS
POOL_DATA_GBP_INVALID_PAGES, POOL_DATA_GBP_INVALID_PAGES, POOL_DATA_GBP_INVALID_PAGES
Number of times an invalid page was found in the local bufferpool, requiring a logical read from the group bufferpool
May occur after an otherwise successful group bufferpool logical read
Bufferpool metrics for prefetchers
Included in the bufferpool table functions
Same as above, but with ASYNC qualifier. Example: POOL_ASYNC_DATA_GBP_L_READS
Are components of the non-async total in the bufferpool table functions

Monitoring – Cluster Facilitator
MON_GET_CF table function
Retreives configured, target and current memory information for cluster caching facilities on
the system, in number of 4K pages
Current – the amount of memory currently allocated
Configured – the maximum amount of memory that will be used, per configuration
Target – during a dynamic resize, the amount that will be allocated when it completes
Columns
Columns
HOST_NAME, ID, DB_NAME
CURRENT_CF_LOCK_SIZE, CONFIGURED_CF_GBP_SIZE, TARGET_CF_GBP_SIZE
Group bufferpool memory
CURRENT_CF_LOCK_SIZE, CONFIGURED_CF_LOCK_SIZE, TARGET_CF_LOCK_SIZE
Global lock memory
CURRENT_CF_SCA_SIZE, CONFIGURED_CF_SCA_SIZE, TARGET_CF_SCA_SIZE
Shared communications area memory
CURRENT_CF_MEM_SIZE, CONFIGURED_CF_MEM_SIZE
Total memory usage

Monitoring – Summary and other views
Summary views provide useful statistics based on data returned by the
table functions
List of summary views
MON_PKG_CACHE_SUMMARY, MON_SERVICE_SUBCLASS_SUMMARY,
MON_WORKLOAD_SUMMARY, MON_CONNECTION_SUMMARY, MON_DB_SUMMARY,
MON_BP_UTILIZATION, MON_TBSP_UTILIZATION
Some useful columns
TOTAL_BP_HIT_RATIO_PERCENT, TOTAL_GBP_HIT_RATIO_PERCENT,
CF_WAIT_TIME_PERCENT
ENV_CF_SYS_RESOURCES
Returns cluster caching facility system resource information, in row format
Columns
ID – CF identifier
NAME – Resource name
VALUE – the value of the name resource
DATATYPE – The data type of the value (example: BIGINT)
UNIT – the data unit of the value, if applicable (example: 4K)

Monitoring – Miscellaneous
Write to table event monitors restart automatically in member-down
scenarios
MONREPORT modules will work in pureScale
Unformatted event table formatters
Formats binary data from the event table into consumable information.
EVMON_FORMAT_UE_TO_XML
EVMON_FORMAT_UE_TO_STREAM
EVMON_FORMAT_UE_TO_TABLES
XML Column to Row formatters
Each Metric is presented as a single row of a table
FORMAT_XML_WAIT_TIMES_BY_ROW
FORMAT_XML_COMPONENT_TIMES_BY_ROW
FORMAT_XML_TIMES_BY_ROW
FORMAT_XML_METRICS_BY_ROW

Episode 2 DB2 pureScale Installation, Instance Management & Monitoring

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