How do it get writes form the lrus in V10
A DBA on IDS 10.00.UC3 (32-bit, 8GB RAM) saw 'onstat -F' reporting zero LRU and foreground writes, only chunk writes, and wondered which parameters to change to force LRU writes. Respondents explained this is normal: with 800,000 buffers and LRU_MAX_DIRTY at 10-25%, the dirty-buffer threshold (tens of thousands of pages) is never reached between 5-minute checkpoints, since only ~15,500 buffers were flushed per hour. LRU writes only matter if checkpoints are too long; chunk writes are more efficient. Lowering LRU_MAX_DIRTY (and raising LRU_MIN_DIRTY) would trigger them, and 'onstat -R' plus message-log checkpoint durations help monitor. Art Kagel also suggested one ipcshm poll thread per CPU VP. The poster accepted that all-chunk writes were fine.
Auto-generated by DrWatson from the posts below — may be imperfect; read the full thread.
I have a new HP Intel 32 bit chip machine with 2 dual core processors
and 8 Gb of memory.
This machine runs one production database (Mostly OLTP) and a test
database that is same thing but very low transactions
When I run on stat -F I have 0 FG writes and 0 LRU writes and Chuunk
writes of 15558 ( NOte this is after only approx 1 hour of production.
I am running INFORMIX 10.00.UC3 workgroup edition.
I am attaching the onconfig file and output of onstat -d
I think I should be getting LRU writes. If you agree what parameters
should I change to get them?
========================================
#**************************************************************************
#
# Licensed Material - Property Of IBM
#
# "Restricted Materials of IBM"
#
# IBM Informix Dynamic Server
# (c) Copyright IBM Corporation 1996, 2005 All rights reserved.
#
# Title: onconfig.std
# Description: IBM Informix Dynamic Server Configuration Parameters
#
#**************************************************************************
# Root Dbspace Configuration
ROOTNAME rootdbs # Root dbspace nameROOTPATH /dev/cciss/inforaw1 # Path for device containing root dbspace
ROOTOFFSET 0 # Offset of root dbspace into device (Kbytes)
ROOTSIZE 8000000 # 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 rootdbs # Location (dbspace) of physical log
PHYSFILE 40000 # Physical log file size (Kbytes)
# Logical Log Configuration
LOGFILES 13 # Number of logical log files
LOGSIZE 8000 # Logical log size (Kbytes)LOG_BACKUP_MODE CONT # Logical log backup mode (MANUAL, CONT)
# Security
# DBCREATE_PERMISSION:
# By default any user can create a database. Uncomment DBCREATE_PERMISSON to
# limit database creation to a specific user. Add a new DBCREATE_PERMISSION
# line for each permitted user.
#DBCREATE_PERMISSION informix
# IFX_EXTEND_ROLE:
# 0 => Disable use of EXTEND role to control who can register
# external routines. This is the default behaviour.
# 1 => Enable use of EXTEND role to control who can register
# external routines.
IFX_EXTEND_ROLE 0 # To control the usage of EXTEND role.
# Tablespace Tablespace Configuration in Root Dbspace
TBLTBLFIRST 0 # First extent size (Kbytes) (0 = default)
TBLTBLNEXT 0 # Next extent size (Kbytes) (0 = default)
# Diagnostics
MSGPATH /informix10.0.uc3/online1204.log # System message log file path
CONSOLE /dev/console # System console message path
# To automatically backup logical logs, edit alarmprogram.sh and set
# BACKUPLOGS=Y
ALARMPROGRAM /informix10.0.uc3/etc/alarmprogram.sh # Alarm program path
ALRM_ALL_EVENTS 0 # Triggers ALARMPROGRAM for any event occur
TBLSPACE_STATS 1 # Maintain tblspace statistics
# System Archive Tape Device
TAPEDEV /dev/st0 # Tape device path
#TAPEDEV /dev/null # Tape device path
TAPEBLK 64 # Tape block size (Kbytes)
TAPESIZE 47201280 # Maximum amount of data to put on tape (Kbytes)
# Log Archive Tape Device
#LTAPEDEV /dev/tapedev # Log tape device path
LTAPEDEV /dev/null # Log tape device path
LTAPEBLK 32 # Log tape block size (Kbytes)
LTAPESIZE 10240 # Max amount of data to put on log tape (Kbytes)
# Optical
STAGEBLOB # Informix Dynamic Server staging area
# System Configuration
SERVERNUM 0 # Unique id corresponding to a OnLine instance
DBSERVERNAME db3v124_shm # Name of default database server
DBSERVERALIASES db3v124fast # List of alternate dbservernames
DBSERVERALIASES db3v124link # List of alternate dbservernames
NETTYPE soctcp,1,100,NET # Configure poll thread(s) for nettype
NETTYPE ipcshm,1,250,CPU # Configure poll thread(s) for nettype
DEADLOCK_TIMEOUT 600 # Max time to wait of lock in distributed env.
RESIDENT 1 # Forced residency flag (Yes = 1, No = 0)
MULTIPROCESSOR 1 # 0 for single-processor, 1 for multi-processor
NUMCPUVPS 3 # 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 1 # Affinity start processor
AFF_NPROCS 3 # Affinity number of processors
# Shared Memory Parameters
LOCKS 200000 # Maximum number of locks
NUMAIOVPS 16 # Number of IO vps
PHYSBUFF 128 # Physical log buffer size (Kbytes)
LOGBUFF 64 # Logical log buffer size (Kbytes)
CLEANERS 20 # Number of buffer cleaner processes
SHMBASE 0x44000000L # Shared memory base address#SHMVIRTSIZE 8192 # initial virtual shared memory segment size
SHMVIRTSIZE 131072 # initial virtual shared memory segment size
SHMADD 32768 # Size of new shared memory segments (Kbytes)#SHMADD 64000 # Size of new shared memory segments (Kbytes)
SHMTOTAL 0 # Total shared memory (Kbytes). 0=>unlimited
CKPTINTVL 300 # Check point interval (in sec)
TXTIMEOUT 300 # Transaction timeout (in sec)#TXTIMEOUT 60 # Transaction timeout (in sec)
#STACKSIZE 32 # Stack size (Kbytes)
STACKSIZE 128 # Stack size (Kbytes)
# Dynamic Logging
# DYNAMIC_LOGS:
# 2 : server automatically add a new logical log when necessary. (ON)
# 1 : notify DBA to add new logical logs when necessary. (ON)
# 0 : cannot add logical log on the fly. (OFF)
#
# When dynamic logging is on, we can have higher values for LTXHWM/LTXEHWM,
# because the server can add new logical logs during long transaction rollback.
# However, to limit the number of new logical logs being added, LTXHWM/LTXEHWM
# can be set to smaller values.
#
# If dynamic logging is off, LTXHWM/LTXEHWM need to be set to smaller values
# to avoid long transaction rollback hanging the server due to lack of logical
# log space, i.e. 50/60 or lower.
#
# In case of system configured with CDR, the difference between LTXHWM and
# LTXEHWM should be atleast 30% so that we could minimize log overrun issue.
DYNAMIC_LOGS 2
LTXHWM 70
LTXEHWM 80
# System Page Size
# BUFFSIZE - OnLine no longer supports this configuration parameter.
# To determine the page size used by OnLine 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 /informix10.0.uc3/etc/dr.lostfound # DR lost+found file path
DRIDXAUTO 0 # DR automatic index repair. 0=off, 1=on
# CDR Variables
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_NIFC
> -----Original Message-----
> From: ids-bounces@iiug.org [mailto:ids-bounces@iiug.org] On Behalf Of
Bill
> Marshall
> Sent: Wednesday, May 03, 2006 7:21 AM
> To: ids@iiug.org
> Subject: How do it get writes form the lrus in V10 [6648]
>
>
> I have a new HP Intel 32 bit chip machine with 2 dual core processors
> and 8 Gb of memory.
>
> This machine runs one production database (Mostly OLTP) and a test
> database that is same thing but very low transactions
>
> When I run on stat -F I have 0 FG writes and 0 LRU writes and Chuunk
> writes of 15558 ( NOte this is after only approx 1 hour of production.
>
> I am running INFORMIX 10.00.UC3 workgroup edition.
>
> I am attaching the onconfig file and output of onstat -d
>
> I think I should be getting LRU writes. If you agree what parameters
> should I change to get them?
>
> ========================================
>
> # The following parameters are related to the buffer pool
> #BUFFERPOOL
>
default,buffers=800000,lrus=8,lru_min_dirty=20.000000,lru_max_dirty=25.0
00
> 000
> BUFFERPOOL>
default,buffers=800000,lrus=8,lru_min_dirty=0.000010,lru_max_dirty=25.00
00
> 00
> #BUFFERPOOL
>
size=2K,buffers=800000,lrus=8,lru_min_dirty=20.000000,lru_max_dirty=25.0
00
> 000
> BUFFERPOOL>
size=2K,buffers=800000,lrus=8,lru_min_dirty=0.000010,lru_max_dirty=10.00
00
> 00
The database will do LRU writes when the number of dirty buffers exceeds
a percentage set in the onconfig file. It will continue writing until
the percentage of dirty buffers reaches another percentage. The
percentages are set by the above parameters. Is this a Windows machine?
If so, you have two buffer pools, one 4K and one 2K. Each of these
tracks dirty buffers separately.
So you will start seeing LRU writes once your 4K buffer pool reaches 25%
dirty (200,000 4K buffers = 800MB) or once your 2K buffer pool reaches
10% dirty (80,000 2K buffers = 160MB). If this isn't a Windows or AIX
machine your default buffer pool size will be 2K, and I'm not certain
what these parameters will produce, since I believe you can only have
one buffer pool of a given size. 'onstat -R' will tell you.
In any case, you don't necessary want to see LRU writes unless you're
concerned about the length of your checkpoints. If you checkpoints are
short I don't think you really have a problem. Chunk writes are
generally more efficient. If your checkpoints are longer than you want,
you can increase LRU writing by decreasing the lru_max_dirty parameter.
On our production OLTP system (which has far fewer buffers) we have it
set to 1.25% to ensure that checkpoints are always very short (2 seconds
or less). You might also increase the lru_min_dirty (since it's
effectively at 0) so that the LRU writes don't last very long (since
they tend to be less efficient).
All of this comes from my knowledge of 9.4 and reading the docs for
10.0. I don't think it's changed too much.
DC
It looks like you never hit the LRU flush levels before a checkpoint perform
chunk write flushing. Your onstat -F shows ~155000 buffers flushed over the
course of an hour, but you have DEFAULT buffer pool flushing at 25% or 200000
buffers and 2K pool flushing at 10% or 80000 buffers and the checkpoint
interval
is 5 minutes so likely less than 15000 buffers were dirty at each checkpoint on
average. Not enough to trigger the LRU flush logic.
FYI, if you use shared memory connections extensively you should have a poll
thread running in each CPU VP for best responsiveness. However, your nettype
for ipcshm has only one configured while you show 3 CPU VPS.
Art S. Kagel
----- Original Message -----
From: Bill Marshall <ids@iiug.org>
At: 5/03 9:24:31
I have a new HP Intel 32 bit chip machine with 2 dual core processors
and 8 Gb of memory.
This machine runs one production database (Mostly OLTP) and a test
database that is same thing but very low transactions
When I run on stat -F I have 0 FG writes and 0 LRU writes and Chuunk
writes of 15558 ( NOte this is after only approx 1 hour of production.
I am running INFORMIX 10.00.UC3 workgroup edition.
I am attaching the onconfig file and output of onstat -d
I think I should be getting LRU writes. If you agree what parameters
should I change to get them?
========================================
#**************************************************************************
#
# Licensed Material - Property Of IBM
#
# "Restricted Materials of IBM"
#
# IBM Informix Dynamic Server
# (c) Copyright IBM Corporation 1996, 2005 All rights reserved.
#
# Title: onconfig.std
# Description: IBM Informix Dynamic Server Configuration Parameters
#
#**************************************************************************
# Root Dbspace Configuration
ROOTNAME rootdbs # Root dbspace nameROOTPATH /dev/cciss/inforaw1 # Path for device containing root dbspace
ROOTOFFSET 0 # Offset of root dbspace into device (Kbytes)
ROOTSIZE 8000000 # 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 rootdbs # Location (dbspace) of physical log
PHYSFILE 40000 # Physical log file size (Kbytes)
# Logical Log Configuration
LOGFILES 13 # Number of logical log files
LOGSIZE 8000 # Logical log size (Kbytes)LOG_BACKUP_MODE CONT # Logical log backup mode (MANUAL, CONT)
# Security
# DBCREATE_PERMISSION:
# By default any user can create a database. Uncomment DBCREATE_PERMISSON to
# limit database creation to a specific user. Add a new DBCREATE_PERMISSION
# line for each permitted user.
#DBCREATE_PERMISSION informix
# IFX_EXTEND_ROLE:
# 0 => Disable use of EXTEND role to control who can register
# external routines. This is the default behaviour.
# 1 => Enable use of EXTEND role to control who can register
# external routines.
IFX_EXTEND_ROLE 0 # To control the usage of EXTEND role.
# Tablespace Tablespace Configuration in Root Dbspace
TBLTBLFIRST 0 # First extent size (Kbytes) (0 = default)
TBLTBLNEXT 0 # Next extent size (Kbytes) (0 = default)
# Diagnostics
MSGPATH /informix10.0.uc3/online1204.log # System message log file path
CONSOLE /dev/console # System console message path
# To automatically backup logical logs, edit alarmprogram.sh and set
# BACKUPLOGS=Y
ALARMPROGRAM /informix10.0.uc3/etc/alarmprogram.sh # Alarm program path
ALRM_ALL_EVENTS 0 # Triggers ALARMPROGRAM for any event occur
TBLSPACE_STATS 1 # Maintain tblspace statistics
# System Archive Tape Device
TAPEDEV /dev/st0 # Tape device path
#TAPEDEV /dev/null # Tape device path
TAPEBLK 64 # Tape block size (Kbytes)
TAPESIZE 47201280 # Maximum amount of data to put on tape (Kbytes)
# Log Archive Tape Device
#LTAPEDEV /dev/tapedev # Log tape device path
LTAPEDEV /dev/null # Log tape device path
LTAPEBLK 32 # Log tape block size (Kbytes)
LTAPESIZE 10240 # Max amount of data to put on log tape (Kbytes)
# Optical
STAGEBLOB # Informix Dynamic Server staging area
# System Configuration
SERVERNUM 0 # Unique id corresponding to a OnLine instance
DBSERVERNAME db3v124_shm # Name of default database server
DBSERVERALIASES db3v124fast # List of alternate dbservernames
DBSERVERALIASES db3v124link # List of alternate dbservernames
NETTYPE soctcp,1,100,NET # Configure poll thread(s) for nettype
NETTYPE ipcshm,1,250,CPU # Configure poll thread(s) for nettype
DEADLOCK_TIMEOUT 600 # Max time to wait of lock in distributed env.
RESIDENT 1 # Forced residency flag (Yes = 1, No = 0)
MULTIPROCESSOR 1 # 0 for single-processor, 1 for multi-processor
NUMCPUVPS 3 # 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 1 # Affinity start processor
AFF_NPROCS 3 # Affinity number of processors
# Shared Memory Parameters
LOCKS 200000 # Maximum number of locks
NUMAIOVPS 16 # Number of IO vps
PHYSBUFF 128 # Physical log buffer size (Kbytes)
LOGBUFF 64 # Logical log buffer size (Kbytes)
CLEANERS 20 # Number of buffer cleaner processes
SHMBASE 0x44000000L # Shared memory base address#SHMVIRTSIZE 8192 # initial virtual shared memory segment size
SHMVIRTSIZE 131072 # initial virtual shared memory segment size
SHMADD 32768 # Size of new shared memory segments (Kbytes)#SHMADD 64000 # Size of new shared memory segments (Kbytes)
SHMTOTAL 0 # Total shared memory (Kbytes). 0=>unlimited
CKPTINTVL 300 # Check point interval (in sec)
TXTIMEOUT 300 # Transaction timeout (in sec)#TXTIMEOUT 60 # Transaction timeout (in sec)
#STACKSIZE 32 # Stack size (Kbytes)
STACKSIZE 128 # Stack size (Kbytes)
# Dynamic Logging
# DYNAMIC_LOGS:
# 2 : server automatically add a new logical log when necessary. (ON)
# 1 : notify DBA to add new logical logs when necessary. (ON)
# 0 : cannot add logical log on the fly. (OFF)
#
# When dynamic logging is on, we can have higher values for LTXHWM/LTXEHWM,
# because the server can add new logical logs during long transaction
rollback.
# However, to limit the number of new logical logs being added, LTXHWM/LTXEHWM
# can be set to smaller values.
#
# If dynamic logging is off, LTXHWM/LTXEHWM need to be set to smaller values
# to avoid long transaction rollback hanging the server due to lack of logical
# log space, i.e. 50/60 or lower.
#
# In case of system configured with CDR, the difference between LTXHWM and
# LTXEHWM should be atleast 30% so that we could minimize log overrun issue.
DYNAMIC_LOGS 2
LTXHWM 70
LTXEHWM 80
# System Page Size
# BUFFSIZE - OnLine no longer supports this configuration parameter.
# To determine the page size used by OnLine 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.
#
> I think I should be getting LRU writes.
Why ? does checkpoint takes too long to complete ? or checkpoint duration
is affecting transaction response time ?
You can monitor LRU queues using 'onstat -R' and check the checkpoint
duration in message log.
On your HP-UX 32-bit system, default pagesize is 2K.
You configured 800,000 buffers with lru_max_dirty set to 10%.
That means when 80,000 buffers are dirty lru queue start flushing dirty
buffers.
Onstat -F output show that only 15,558 buffers were flushed during
checkpoint.
so there is no way that lru flushing will start.
Regards,
Nilesh
Wednesday, May 03, 2006 8:29 AM
To: ids@iiug.org
cc:
From: "Bill Marshall" <cwm@stober.com>
Subject: How do it get writes form the lrus in V10 [6648]
I have a new HP Intel 32 bit chip machine with 2 dual core processors
and 8 Gb of memory.
This machine runs one production database (Mostly OLTP) and a test
database that is same thing but very low transactions
When I run on stat -F I have 0 FG writes and 0 LRU writes and Chuunk
writes of 15558 ( NOte this is after only approx 1 hour of production.
I am running INFORMIX 10.00.UC3 workgroup edition.
I am attaching the onconfig file and output of onstat -d
I think I should be getting LRU writes. If you agree what parameters
should I change to get them?
========================================
#**************************************************************************
#
# Licensed Material - Property Of IBM
#
# "Restricted Materials of IBM"
#
# IBM Informix Dynamic Server
# (c) Copyright IBM Corporation 1996, 2005 All rights reserved.
#
# Title: onconfig.std
# Description: IBM Informix Dynamic Server Configuration Parameters
#
#**************************************************************************
# Root Dbspace Configuration
ROOTNAME rootdbs # Root dbspace nameROOTPATH /dev/cciss/inforaw1 # Path for device containing root dbspace
ROOTOFFSET 0 # Offset of root dbspace into device (Kbytes)
ROOTSIZE 8000000 # 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 rootdbs # Location (dbspace) of physical log
PHYSFILE 40000 # Physical log file size (Kbytes)
# Logical Log Configuration
LOGFILES 13 # Number of logical log files
LOGSIZE 8000 # Logical log size (Kbytes)LOG_BACKUP_MODE CONT # Logical log backup mode (MANUAL, CONT)
# Security
# DBCREATE_PERMISSION:
# By default any user can create a database. Uncomment DBCREATE_PERMISSON
to
# limit database creation to a specific user. Add a new DBCREATE_PERMISSION
# line for each permitted user.
#DBCREATE_PERMISSION informix
# IFX_EXTEND_ROLE:
# 0 => Disable use of EXTEND role to control who can register
# external routines. This is the default behaviour.
# 1 => Enable use of EXTEND role to control who can register
# external routines.
IFX_EXTEND_ROLE 0 # To control the usage of EXTEND role.
# Tablespace Tablespace Configuration in Root Dbspace
TBLTBLFIRST 0 # First extent size (Kbytes) (0 = default)
TBLTBLNEXT 0 # Next extent size (Kbytes) (0 = default)
# Diagnostics
MSGPATH /informix10.0.uc3/online1204.log # System message log file path
CONSOLE /dev/console # System console message path
# To automatically backup logical logs, edit alarmprogram.sh and set
# BACKUPLOGS=Y
ALARMPROGRAM /informix10.0.uc3/etc/alarmprogram.sh # Alarm program path
ALRM_ALL_EVENTS 0 # Triggers ALARMPROGRAM for any event occur
TBLSPACE_STATS 1 # Maintain tblspace statistics
# System Archive Tape Device
TAPEDEV /dev/st0 # Tape device path
#TAPEDEV /dev/null # Tape device path
TAPEBLK 64 # Tape block size (Kbytes)
TAPESIZE 47201280 # Maximum amount of data to put on tape (Kbytes)
# Log Archive Tape Device
#LTAPEDEV /dev/tapedev # Log tape device path
LTAPEDEV /dev/null # Log tape device path
LTAPEBLK 32 # Log tape block size (Kbytes)
LTAPESIZE 10240 # Max amount of data to put on log tape (Kbytes)
# Optical
STAGEBLOB # Informix Dynamic Server staging area
# System Configuration
SERVERNUM 0 # Unique id corresponding to a OnLine instance
DBSERVERNAME db3v124_shm # Name of default database server
DBSERVERALIASES db3v124fast # List of alternate dbservernames
DBSERVERALIASES db3v124link # List of alternate dbservernames
NETTYPE soctcp,1,100,NET # Configure poll thread(s) for nettype
NETTYPE ipcshm,1,250,CPU # Configure poll thread(s) for nettype
DEADLOCK_TIMEOUT 600 # Max time to wait of lock in distributed env.
RESIDENT 1 # Forced residency flag (Yes = 1, No = 0)
MULTIPROCESSOR 1 # 0 for single-processor, 1 for multi-processor
NUMCPUVPS 3 # 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 1 # Affinity start processor
AFF_NPROCS 3 # Affinity number of processors
# Shared Memory Parameters
LOCKS 200000 # Maximum number of locks
NUMAIOVPS 16 # Number of IO vps
PHYSBUFF 128 # Physical log buffer size (Kbytes)
LOGBUFF 64 # Logical log buffer size (Kbytes)
CLEANERS 20 # Number of buffer cleaner processes
SHMBASE 0x44000000L # Shared memory base address#SHMVIRTSIZE 8192 # initial virtual shared memory segment size
SHMVIRTSIZE 131072 # initial virtual shared memory segment size
SHMADD 32768 # Size of new shared memory segments (Kbytes)#SHMADD 64000 # Size of new shared memory segments (Kbytes)
SHMTOTAL 0 # Total shared memory (Kbytes). 0=>unlimited
CKPTINTVL 300 # Check point interval (in sec)
TXTIMEOUT 300 # Transaction timeout (in sec)#TXTIMEOUT 60 # Transaction timeout (in sec)
#STACKSIZE 32 # Stack size (Kbytes)
STACKSIZE 128 # Stack size (Kbytes)
# Dynamic Logging
# DYNAMIC_LOGS:
# 2 : server automatically add a new logical log when necessary. (ON)
# 1 : notify DBA to add new logical logs when necessary. (ON)
# 0 : cannot add logical log on the fly. (OFF)
#
# When dynamic logging is on, we can have higher values for LTXHWM/LTXEHWM,
# because the server can add new logical logs during long transaction
rollback.
# However, to limit the number of new logical logs being added,
LTXHWM/LTXEHWM
# can be set to smaller values.
#
# If dynamic logging is off, LTXHWM/LTXEHWM need to be set to smaller
values
# to avoid long transaction rollback hanging the server due to lack of
logical
# log space, i.e. 50/60 or lower.
#
# In case of system configured with CDR, the difference between LTXHWM and
# LTXEHWM should be atleast 30% so that we could minimize log overrun
issue.
DYNAMIC_LOGS 2
LTXHWM 70
LTXEHWM 80
# System Page Size
# BUFFSIZE - OnLine no longer supports this configuration parameter.
# To determine the page size used by OnLine on your platform
# see the last line of output from the command, 'onstat -b'.
# Recovery Variables
# OFF_RECVRY_THREADS:
# Number of parallel worker th
Thanks to everyone for our response.
I now understand that having all chuck writes is ok.
Nilesh Ozarkar wrote:
>> I think I should be getting LRU writes.
>>
>
> Why ? does checkpoint takes too long to complete ? or checkpoint duration
> is affecting transaction response time ?
>
> You can monitor LRU queues using 'onstat -R' and check the checkpoint
> duration in message log.
>
> On your HP-UX 32-bit system, default pagesize is 2K.
> You configured 800,000 buffers with lru_max_dirty set to 10%.
> That means when 80,000 buffers are dirty lru queue start flushing dirty
> buffers.
> Onstat -F output show that only 15,558 buffers were flushed during
> checkpoint.
> so there is no way that lru flushing will start.
>
> Regards,
> Nilesh
>
> Wednesday, May 03, 2006 8:29 AM
> To: ids@iiug.org
> cc:
> From: "Bill Marshall" <cwm@stober.com>
> Subject: How do it get writes form the lrus in V10 [6648]
>
> I have a new HP Intel 32 bit chip machine with 2 dual core processors
> and 8 Gb of memory.
>
> This machine runs one production database (Mostly OLTP) and a test
> database that is same thing but very low transactions
>
> When I run on stat -F I have 0 FG writes and 0 LRU writes and Chuunk
> writes of 15558 ( NOte this is after only approx 1 hour of production.
>
> I am running INFORMIX 10.00.UC3 workgroup edition.
>
> I am attaching the onconfig file and output of onstat -d
>
> I think I should be getting LRU writes. If you agree what parameters
> should I change to get them?
>
> ========================================
>
> #**************************************************************************
> #
> # Licensed Material - Property Of IBM
> #
> # "Restricted Materials of IBM"
> #
> # IBM Informix Dynamic Server
> # (c) Copyright IBM Corporation 1996, 2005 All rights reserved.
> #
> # Title: onconfig.std
> # Description: IBM Informix Dynamic Server Configuration Parameters
> #
> #**************************************************************************
>
> # Root Dbspace Configuration
>
> ROOTNAME rootdbs # Root dbspace name> ROOTPATH /dev/cciss/inforaw1 # Path for device containing root dbspace
> ROOTOFFSET 0 # Offset of root dbspace into device (Kbytes)
> ROOTSIZE 8000000 # 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 rootdbs # Location (dbspace) of physical log
> PHYSFILE 40000 # Physical log file size (Kbytes)>
> # Logical Log Configuration
>
> LOGFILES 13 # Number of logical log files
> LOGSIZE 8000 # Logical log size (Kbytes)> LOG_BACKUP_MODE CONT # Logical log backup mode (MANUAL, CONT)
>
> # Security
> # DBCREATE_PERMISSION:
> # By default any user can create a database. Uncomment DBCREATE_PERMISSON
> to
> # limit database creation to a specific user. Add a new DBCREATE_PERMISSION
> # line for each permitted user.
>
> #DBCREATE_PERMISSION informix
>
> # IFX_EXTEND_ROLE:
> # 0 => Disable use of EXTEND role to control who can register
> # external routines. This is the default behaviour.
> # 1 => Enable use of EXTEND role to control who can register
> # external routines.
>
> IFX_EXTEND_ROLE 0 # To control the usage of EXTEND role.>
> # Tablespace Tablespace Configuration in Root Dbspace
>
> TBLTBLFIRST 0 # First extent size (Kbytes) (0 = default)
> TBLTBLNEXT 0 # Next extent size (Kbytes) (0 = default)>
> # Diagnostics
>
> MSGPATH /informix10.0.uc3/online1204.log # System message log file path
> CONSOLE /dev/console # System console message path>
> # To automatically backup logical logs, edit alarmprogram.sh and set
> # BACKUPLOGS=Y
> ALARMPROGRAM /informix10.0.uc3/etc/alarmprogram.sh # Alarm program path
> ALRM_ALL_EVENTS 0 # Triggers ALARMPROGRAM for any event occur
> TBLSPACE_STATS 1 # Maintain tblspace statistics>
> # System Archive Tape Device
>
> TAPEDEV /dev/st0 # Tape device path
> #TAPEDEV /dev/null # Tape device path
> TAPEBLK 64 # Tape block size (Kbytes)
> TAPESIZE 47201280 # Maximum amount of data to put on tape (Kbytes)>
> # Log Archive Tape Device
>
> #LTAPEDEV /dev/tapedev # Log tape device path
> LTAPEDEV /dev/null # Log tape device path
> LTAPEBLK 32 # Log tape block size (Kbytes)
> LTAPESIZE 10240 # Max amount of data to put on log tape (Kbytes)>
> # Optical
>
> STAGEBLOB # Informix Dynamic Server staging area
>
> # System Configuration
>
> SERVERNUM 0 # Unique id corresponding to a OnLine instance
> DBSERVERNAME db3v124_shm # Name of default database server
> DBSERVERALIASES db3v124fast # List of alternate dbservernames
> DBSERVERALIASES db3v124link # List of alternate dbservernames
> NETTYPE soctcp,1,100,NET # Configure poll thread(s) for nettype
> NETTYPE ipcshm,1,250,CPU # Configure poll thread(s) for nettype
> DEADLOCK_TIMEOUT 600 # Max time to wait of lock in distributed env.
> RESIDENT 1 # Forced residency flag (Yes = 1, No = 0)
>
> MULTIPROCESSOR 1 # 0 for single-processor, 1 for multi-processor
> NUMCPUVPS 3 # 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 1 # Affinity start processor
> AFF_NPROCS 3 # Affinity number of processors>
> # Shared Memory Parameters
>
> LOCKS 200000 # Maximum number of locks
> NUMAIOVPS 16 # Number of IO vps
> PHYSBUFF 128 # Physical log buffer size (Kbytes)
> LOGBUFF 64 # Logical log buffer size (Kbytes)
> CLEANERS 20 # Number of buffer cleaner processes
> SHMBASE 0x44000000L # Shared memory base address> #SHMVIRTSIZE 8192 # initial virtual shared memory segment size
> SHMVIRTSIZE 131072 # initial virtual shared memory segment size
> SHMADD 32768 # Size of new shared memory segments (Kbytes)> #SHMADD 64000 # Size of new shared memory segments (Kbytes)
> SHMTOTAL 0 # Total shared memory (Kbytes). 0=>unlimited
> CKPTINTVL 300 # Check point interval (in sec)
> TXTIMEOUT 300 # Transaction timeout (in sec)> #TXTIMEOUT 60 # Transaction timeout (in sec)
> #STACKSIZE 32 # Stack size (Kbytes)
> STACKSIZE 128 # Stack size (Kbytes)>
> # Dynamic Logging
> # DYNAMIC_LOGS:
> # 2 : server automatically add a new logical log when necessary. (ON)
> # 1 : notify DBA to add new logical logs when necessary. (ON)
> # 0 : cannot add logical log on the fly. (OFF)
> #
> # When dynamic logging is on, we can have higher values for LTXHWM/LTXEHWM,
> # because the server can add new logical logs during long transaction
> rollback.
> # However, to limit the number of new logical logs being added,
> LTXHWM/LTXEHWM
> # can be set to smaller values.
> #
> # If dynamic logging is off, LTXHWM/LTXEHWM need to be set to smaller
> values
> # to avoid long transaction rollback hanging the server due to lack of
> logical
> # log space, i.e. 50/60 or lower.
> #
> # In case of system configured with CDR, the difference between LTXHWM a
OK? Maybe. Expected? Definitely. Here's the poop:
Chunk writes minimize system overhead and IO channel abuse by the DB server.
LRU writes minimize checkpoint wait times and maximize server throughput.
For an OLTP system 60-80% LRU writes is about the right balance for a
DSS/reporting server maby reverse that to about 60% Chunk writes and for a DW
server 100% Chunk writes. During bulk data loads you definitely want to retune
towards Chunk writes regardless of the server's day-to-day specialization.
Art S. Kagel
----- Original Message -----
From: Bill Marshall <ids@iiug.org>
At: 5/04 15:44:48
Thanks to everyone for our response.
I now understand that having all chuck writes is ok.
Nilesh Ozarkar wrote:
>> I think I should be getting LRU writes.
>>
>
> Why ? does checkpoint takes too long to complete ? or checkpoint duration
> is affecting transaction response time ?
>
> You can monitor LRU queues using 'onstat -R' and check the checkpoint
> duration in message log.
>
> On your HP-UX 32-bit system, default pagesize is 2K.
> You configured 800,000 buffers with lru_max_dirty set to 10%.
> That means when 80,000 buffers are dirty lru queue start flushing dirty
> buffers.
> Onstat -F output show that only 15,558 buffers were flushed during
> checkpoint.
> so there is no way that lru flushing will start.
>
> Regards,
> Nilesh
>
> Wednesday, May 03, 2006 8:29 AM
> To: ids@iiug.org
> cc:
> From: "Bill Marshall" <cwm@stober.com>
> Subject: How do it get writes form the lrus in V10 [6648]
>
> I have a new HP Intel 32 bit chip machine with 2 dual core processors
> and 8 Gb of memory.
>
> This machine runs one production database (Mostly OLTP) and a test
> database that is same thing but very low transactions
>
> When I run on stat -F I have 0 FG writes and 0 LRU writes and Chuunk
> writes of 15558 ( NOte this is after only approx 1 hour of production.
>
> I am running INFORMIX 10.00.UC3 workgroup edition.
>
> I am attaching the onconfig file and output of onstat -d
>
> I think I should be getting LRU writes. If you agree what parameters
> should I change to get them?
>
> ========================================
>
> #**************************************************************************
> #
> # Licensed Material - Property Of IBM
> #
> # "Restricted Materials of IBM"
> #
> # IBM Informix Dynamic Server
> # (c) Copyright IBM Corporation 1996, 2005 All rights reserved.
> #
> # Title: onconfig.std
> # Description: IBM Informix Dynamic Server Configuration Parameters
> #
> #**************************************************************************
>
> # Root Dbspace Configuration
>
> ROOTNAME rootdbs # Root dbspace name> ROOTPATH /dev/cciss/inforaw1 # Path for device containing root dbspace
> ROOTOFFSET 0 # Offset of root dbspace into device (Kbytes)
> ROOTSIZE 8000000 # 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 rootdbs # Location (dbspace) of physical log
> PHYSFILE 40000 # Physical log file size (Kbytes)>
> # Logical Log Configuration
>
> LOGFILES 13 # Number of logical log files
> LOGSIZE 8000 # Logical log size (Kbytes)> LOG_BACKUP_MODE CONT # Logical log backup mode (MANUAL, CONT)
>
> # Security
> # DBCREATE_PERMISSION:
> # By default any user can create a database. Uncomment DBCREATE_PERMISSON
> to
> # limit database creation to a specific user. Add a new DBCREATE_PERMISSION
> # line for each permitted user.
>
> #DBCREATE_PERMISSION informix
>
> # IFX_EXTEND_ROLE:
> # 0 => Disable use of EXTEND role to control who can register
> # external routines. This is the default behaviour.
> # 1 => Enable use of EXTEND role to control who can register
> # external routines.
>
> IFX_EXTEND_ROLE 0 # To control the usage of EXTEND role.>
> # Tablespace Tablespace Configuration in Root Dbspace
>
> TBLTBLFIRST 0 # First extent size (Kbytes) (0 = default)
> TBLTBLNEXT 0 # Next extent size (Kbytes) (0 = default)>
> # Diagnostics
>
> MSGPATH /informix10.0.uc3/online1204.log # System message log file path
> CONSOLE /dev/console # System console message path>
> # To automatically backup logical logs, edit alarmprogram.sh and set
> # BACKUPLOGS=Y
> ALARMPROGRAM /informix10.0.uc3/etc/alarmprogram.sh # Alarm program path
> ALRM_ALL_EVENTS 0 # Triggers ALARMPROGRAM for any event occur
> TBLSPACE_STATS 1 # Maintain tblspace statistics>
> # System Archive Tape Device
>
> TAPEDEV /dev/st0 # Tape device path
> #TAPEDEV /dev/null # Tape device path
> TAPEBLK 64 # Tape block size (Kbytes)
> TAPESIZE 47201280 # Maximum amount of data to put on tape (Kbytes)>
> # Log Archive Tape Device
>
> #LTAPEDEV /dev/tapedev # Log tape device path
> LTAPEDEV /dev/null # Log tape device path
> LTAPEBLK 32 # Log tape block size (Kbytes)
> LTAPESIZE 10240 # Max amount of data to put on log tape (Kbytes)>
> # Optical
>
> STAGEBLOB # Informix Dynamic Server staging area
>
> # System Configuration
>
> SERVERNUM 0 # Unique id corresponding to a OnLine instance
> DBSERVERNAME db3v124_shm # Name of default database server
> DBSERVERALIASES db3v124fast # List of alternate dbservernames
> DBSERVERALIASES db3v124link # List of alternate dbservernames
> NETTYPE soctcp,1,100,NET # Configure poll thread(s) for nettype
> NETTYPE ipcshm,1,250,CPU # Configure poll thread(s) for nettype
> DEADLOCK_TIMEOUT 600 # Max time to wait of lock in distributed env.
> RESIDENT 1 # Forced residency flag (Yes = 1, No = 0)
>
> MULTIPROCESSOR 1 # 0 for single-processor, 1 for multi-processor
> NUMCPUVPS 3 # 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 1 # Affinity start processor
> AFF_NPROCS 3 # Affinity number of processors>
> # Shared Memory Parameters
>
> LOCKS 200000 # Maximum number of locks
> NUMAIOVPS 16 # Number of IO vps
> PHYSBUFF 128 # Physical log buffer size (Kbytes)
> LOGBUFF 64 # Logical log buffer size (Kbytes)
> CLEANERS 20 # Number of buffer cleaner processes
> SHMBASE 0x44000000L # Shared memory base address> #SHMVIRTSIZE 8192 # initial virtual shared memory segment size
> SHMVIRTSIZE 131072 # initial virtual shared memory segment size
> SHMADD 32768 # Size of new shared memory segments (Kbytes)> #SHMADD 64000 # Size of new shared memory segments (Kbytes)
> SHMTOTAL 0 # Total shared memory (Kbytes). 0=>unlimited
> CKPTINTVL 300 # Check point interval (in sec)
> TXTIMEOUT 300 # Transaction timeout (in sec)> #TXTIMEOUT 60 # Transaction timeout (in sec)
> #STACKSIZE 32 # Stack size (Kbytes)
> STACKSIZE 128 # Stack size (Kbytes)>
> # Dynamic Logging
> # DYNAMIC_LOGS:
> # 2 : server automatically add a new logical log when necessary. (ON)
> # 1 : notify DBA to add new logical logs when necessary. (ON)
Related threads
- IDS 10 table-level restore
- Informix Development Webinar December 11, 2007
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- Migrate from HP PA-RISC to HP ITANIUM by ontape