IDS Forum

Re: How to avoid blocking checkpoints?

Posted By: Art Kagel
Date: Monday, 15 May 2017, at 2:42 p.m.

In Response To: How to avoid blocking checkpoints? (GUSTAVO ECHENIQUE)

Gustavo:

Are the chunks RAW or COOKED? If cooked then you should have at least 1.5
AIO VPs per active (non-temp) chunk and you only have one. You have seven
CLEANER threads, now many non-temp chunks do you have? You should have at
least one CLEANER per actively modified chunk (those with lots of writes in
onstat -D output). Post your onstat -g iov, onstat -F and onstat -R output.
Maybe we'll see something.

Art

Art S. Kagel, President and Principal Consultant
ASK Database Management
www.askdbmgt.com

Blog: http://informix-myview.blogspot.com/

Disclaimer: Please keep in mind that my own opinions are my own opinions
and do not reflect on the IIUG, nor any other organization with which I am
associated either explicitly, implicitly, or by inference. Neither do
those opinions reflect those of other individuals affiliated with any
entity with which I am affiliated nor those of the entities themselves.

On Mon, May 15, 2017 at 12:01 PM, GUSTAVO ECHENIQUE <
gustavo.echenique@cemdo.com.ar> wrote:

> Dear:
>
> I have a problem with the checkpoints of an IDS 7.31 TD6 engine running on
> a
> Windows 2008 Server R2. The server has an array of 4 disks in RAID 5 for
> the
> data, and 3 arrays more than 2 disks in RAID 1 for the dbspaces temorial,
> for
> the Logdbs, and for the Physical Log, respectively.
>
> When they occur (the checkpoints), sometimes they take a long time
> (between 4
> and 6 minutes).
>
> I have tried changing the size of the physical log, as they say in some IBM
> documents (taking it to 110%) of the total size of Logical Logs, but the
> problem persists.
>
> I transcribe my onconfig to see if any one notice any parameters that have
> to
> be modified .:
>
> ############################################################
> ###############
> # Root Dbspace Configuration
>
> ROOTNAME rootdbs # Root dbspace name
> ROOTPATH C:\IFMXDATA\ol_abril\rootdbs_dat.000
>
> # Path for device containing root dbspace
> ROOTOFFSET 0 # Offset of root dbspace into device (Kbytes)
> ROOTSIZE 122880 # Size of root dbspace (Kbytes)
>
> # Disk Mirroring Configuration Parameters
>
> MIRROR 0 # Mirroring flag (Yes = 1, No = 0)
> MIRRORPATH # Path for device containing mirrored root
> MIRROROFFSET 0 # Offset into mirrored device (Kbytes)
>
> # Physical Log Configuration
>
> PHYSDBS physdbs # Location (dbspace) of physical log
> PHYSFILE 281600 # Physical log file size (Kbytes)
>
> # Logical Log Configuration
>
> LOGFILES 20 # Number of logical log files
> LOGSIZE 51200 # Logical log size (Kbytes)
> LOG_BACKUP_MODE CONT # Logical log backup mode (MANUAL, CONT)
>
> # Diagnostics
>
> MSGPATH C:\Informix\ol_abril.log # System message log file path
> CONSOLE C:\Informix\conol_abril.log # System console message path
> ALARMPROGRAM C:\Informix\etc\no_log.bat # Alarm program path
>
> # System Diagnostic Script.
> # SYSALARMPROGRAM - Full path of the system diagnostic script (e.g.
> # c:\informix\etc\evidence.bat.) Set this parameter
> # if you want a different Diagnostic Script than
> # {INFORMIXDIR}\etc\evidence.bat, which is default.
>
> # System Archive Tape Device
>
> TAPEDEV NUL # Tape device path
> #TAPEDEV \\.\TAPE0 # Tape device path
> TAPEBLK 16 # Tape block size (Kbytes)
> TAPESIZE 10240 # Maximum amount of data to put on tape (Kbytes)
>
> # Log Archive Tape Device
>
> LTAPEDEV NUL # Log tape device path
> #LTAPEDEV \\.\TAPE1 # Log tape device path
> LTAPEBLK 16 # Log tape block size (Kbytes)
> LTAPESIZE 10240 # Max amount of data to put on log tape (Kbytes)
>
> # Optical
>
> STAGEBLOB # Informix Dynamic Server/Optical staging area
> OPTICAL_LIB_PATH # Location of Optical Subsystem driver DLL
>
> # System Configuration
>
> SERVERNUM 0 # Unique id corresponding to a server instance
> DBSERVERNAME ol_abril # Name of default Dynamic Server
> DBSERVERALIASES # List of alternate dbservernames
> NETTYPE soctcp,1,,NET # Override sqlhosts nettype parameters
> DEADLOCK_TIMEOUT 60 # Max time to wait of lock in distributed env.
> RESIDENT 0 # Forced residency flag (Yes = 1, No = 0)
>
> MULTIPROCESSOR 1 # 0 for single-processor, 1 for multi-processor
> NUMCPUVPS 7 # Number of user (cpu) vps
> SINGLE_CPU_VP 0 # If non-zero, limit number of cpu vps to one
>
> NOAGE 0 # Process aging
> AFF_SPROC 0 # Affinity start processor
> AFF_NPROCS 0 # Affinity number of processors
>
> # Shared Memory Parameters
>
> LOCKS 200000 # Maximum number of locks
> BUFFERS 300000 # Maximum number of shared buffers
> NUMAIOVPS 1 # Number of IO vps
> PHYSBUFF 128 # Physical log buffer size (Kbytes)
> LOGBUFF 128 # Logical log buffer size (Kbytes)
> LOGSMAX 20 # Maximum number of logical log files
> CLEANERS 7 # Number of buffer cleaner processes
> SHMBASE 0xc000000 # Shared memory base address
> SHMVIRTSIZE 131072 # initial virtual shared memory segment size
> SHMADD 16384 # Size of new shared memory segments (Kbytes)
> SHMTOTAL 0 # Total shared memory (Kbytes). 0=>unlimited
> CKPTINTVL 300 # Check point interval (in sec)
> LRUS 128 # Number of LRU queues
> LRU_MAX_DIRTY 5 # LRU percent dirty begin cleaning limit
> LRU_MIN_DIRTY 1 # LRU percent dirty end cleaning limit
> LTXHWM 50 # Long transaction high water mark percentage
> LTXEHWM 60 # Long transaction high water mark (exclusive)
> TXTIMEOUT 0x12c # Transaction timeout (in sec)
> STACKSIZE 32 # Stack size (Kbytes)
>
> # System Page Size
> # BUFFSIZE - Dynamic Server no longer supports this configuration
> parameter.
> # To determine the page size used by Dynamic Server on your platform
> # see the last line of output from the command, 'onstat -b'.
>
> # Recovery Variables
> # OFF_RECVRY_THREADS:
> # Number of parallel worker threads during fast recovery or an offline
> restore.
> # ON_RECVRY_THREADS:
> # Number of parallel worker threads during an online restore.
>
> OFF_RECVRY_THREADS 10 # Default number of offline worker threads
> ON_RECVRY_THREADS 1 # Default number of online worker threads
>
> # Data Replication Variables
> # DRAUTO: 0 manual, 1 retain type, 2 reverse type
> DRAUTO 0 # DR automatic switchover
> DRINTERVAL 30 # DR max time between DR buffer flushes (in sec)
> DRTIMEOUT 30 # DR network timeout (in sec)
> DRLOSTFOUND \tmp # DR lost+found file path
>
> # CDR Variables
> CDR_LOGBUFFERS 2048 # size of log reading buffer pool (Kbytes)
> CDR_EVALTHREADS 1,2 # evaluator threads (per-cpu-vp,additional)
> CDR_DSLOCKWAIT 5 # DS lockwait timeout (seconds)
> CDR_QUEUEMEM 4096 # Maximum amount of memory for any CDR queue (Kbytes)
> CDR_LOGDELTA 30 # % of log space allowed in queue memory
> CDR_NUMCONNECT 16 # Expected connections per server
> CDR_NIFRETRY 300 # Connection retry (seconds)
> CDR_NIFCOMPRESS 0 # Link level compression (-1 never, 0 none, 9 max)
>
> # Backup/Restore variables
> BAR_ACT_LOG C:\Informix\bar_ol_abril.log #Path of log file for onbar.exe
> BAR_MAX_BACKUP 0
> BAR_RETRY 1
> BAR_NB_XPORT_COUNT 10
> BAR_XFER_BUF_SIZE 15
> BAR_BSALIB_PATH C:\ISM\2.20\bin\libbsa.dll # Location of ISM XBSA DLL
>
> RESTARTABLE_RESTORE on #To support restartable restore..values on/off
>
> # Informix Storage Manager variables
> ISM_DATA_POOL ISMData
> ISM_LOG_POOL ISMLogs
>
> # Read Ahead Variables
> RA_PAGES 60 # Number of pages to attempt to read ahead
> RA_THRESHOLD 64 # Number of pages left before next group
>
> # DBSPACETEMP:
> # Dynamic Server equivalent of DBTEMP for SE. This is the list of dbspaces
> # that the Dynamic Server SQL Engine will use to create temp tables etc.
> # If specified it must be a colon separated list of dbspaces that exist
> # when the Dynamic Server system is brought online. If not specified, or if
> # all dbspaces specified are invalid, various ad hoc queries will create
> # temporary files in /tmp instead.
>
> DBSPACETEMP
> tmp0,tmp1,tmp2,tmp3,tmp4,tmp5,tmp6,tmp7,tmp8,tmp9,tmp10,
> tmp11,tmp12,tmp13,tmp14,tmp15,tmp16,tmp17,tmp18,tmp19,tmp20,
> tmp21,tmp22,tmp23,tmp24,tmp25,tmp26,tmp27,tmp28,tmp29
>
> # Default temp dbspaces
>
> # DUMP*:
> # The following parameters control the type of diagnostics information
> which
> # is preserved when an unanticipated error condition (assertion failure)
> occurs
> # during Dynamic Server operations.
> # For DUMPSHMEM, DUMPGCORE and DUMPCORE 1 means Yes, 0 means No.
>
> DUMPDIR \tmp # Preserve diagnostics in this directory
> DUMPSHMEM 1 # Dump a copy of shared memory
> DUMPGCORE 0 # Dump a core image using 'gcore'
> DUMPCORE 0 # Dump a core image (Warning:this aborts Dynamic
> DUMPCNT 1 # Number of shared memory or gcore dumps for
>
> # a single user's session
>
> FILLFACTOR 90 # Fill factor for building indexes
>
> # method for Dynamic Server to use when determining current time
> USEOSTIME 0 # 0: use internal time(fast), 1: get time from OS(slow)
>
> # Parallel Database Queries (pdq)
> MAX_PDQPRIORITY 100 # Maximum allowed pdqpriority
> DS_MAX_QUERIES 8 # Maximum number of decision support queries Original(32)
> DS_TOTAL_MEMORY 16384 # Decision support memory (Kbytes) Original(4096)
> DS_MAX_SCANS 1048576 # Maximum number of decision support scans
> DATASKIP off # List of dbspaces to skip
>
> # OPTCOMPIND
> # 0 => Nested loop joins will be preferred (where
> # possible) over sortmerge joins and hash joins.
> # 1 => If the transaction isolation mode is not
> # "repeatable read", optimizer behaves as in (2)
> # below. Otherwise it behaves as in (0) above.
> # 2 => Use costs regardless of the transaction isolation
> # mode. Nested loop joins are not necessarily
> # preferred. Optimizer bases its decision purely
> # on costs.
> OPTCOMPIND 2 # To hint the optimizer
>
> ONDBSPACEDOWN 2 # Dbspace down option: 0 = CONTINUE, 1 = ABORT, 2 = WAIT
> LBU_PRESERVE 0 # Preserve last log for log backup
> OPCACHEMAX 0 # Maximum optical cache size (Kbytes)
>
> # HETERO_COMMIT (Gateway participation in distributed transactions)
> # 1 => Heterogeneous Commit is enabled
> # 0 (or any other value) => Heterogeneous Commit is disabled
> HETERO_COMMIT 0
>
> # Optimization goal: -1 = ALL_ROWS(Default), 0 = FIRST_ROWS
> OPT_GOAL -1
>
> # Optimizer DIRECTIVES ON (1/Default) or OFF (0)
> DIRECTIVES 1
>
> Thank you for your attention.
>
>
> ************************************************************
> *******************
> Forum Note: Use "Reply" to post a response in the discussion forum.
>
>

Messages In This Thread

• How to avoid blocking checkpoints?
  GUSTAVO ECHENIQUE -- Monday, 15 May 2017, at 1:01 p.m.
  • Re: How to avoid blocking checkpoints?
    JACQUES RENAUT -- Monday, 15 May 2017, at 1:47 p.m.
    • Re: How to avoid blocking checkpoints?
      Andreas Legner -- Monday, 15 May 2017, at 5:28 p.m.
  • Re: How to avoid blocking checkpoints?
    Art Kagel -- Monday, 15 May 2017, at 2:42 p.m.
    • Re: How to avoid blocking checkpoints?
      GUSTAVO ECHENIQUE -- Monday, 15 May 2017, at 5:30 p.m.
      • Re: How to avoid blocking checkpoints?
        david@smooth1.co.uk -- Monday, 15 May 2017, at 5:47 p.m.
      • Re: How to avoid blocking checkpoints?
        Art Kagel -- Monday, 15 May 2017, at 5:54 p.m.
  • Re: How to avoid blocking checkpoints?
    GUSTAVO ECHENIQUE -- Wednesday, 17 May 2017, at 5:59 p.m.
    • Re: How to avoid blocking checkpoints?
      ERIC VERCELLETTO -- Saturday, 20 May 2017, at 3:50 a.m.

IDS Forum is maintained by Administrator with WebBBS 5.12.