Confirm that SHMMAX kernel parameter is set datastore size

Question

Hi,
I'm getting below exception when i'm trying to create datastore. The error is complaining about failure to create shared memory segment.
I did go through the T-10 documentation and various post on this forum, and have made sure that the OS and the DSN settings are as per the recommended values. The values meets(or rather exceeds) the minimum values.
The values are based on below formulas:
kernel.shmmax (in bytes) = Should be >= PermSize + TempSize + LogBufMB +~50MB overhead
kernel.shmall (in pages) = Should be >= ceil ( SHMMAX / PAGE_SIZE)
SwapTotal (in KB) = Swap space should generally be at least 1.5x total physical memory size. It should be sufficient to allow allocation of a large enough shared memory segment
TempSize (in MB) = Should be >= 40 MB + ceiling( PermSize / 8 MB)
I have pasted below following things. Please, can any one help me resolve this issue.
- exception in ttmessg.log
- output of cat /etc/sysctl.conf
- sys.odbc.ini datastore configuration
- cat /proc/meminfo
- Swap space
- output of ttstatus
- output of ttversion
[oracle@ttnode1 info]$ ttdaemonadmin -stop
TimesTen Daemon stopped.
[oracle@ttnode1 info]$ ttdaemonadmin -start
TimesTen Daemon startup OK.
[oracle@ttnode1 info]$ ttisql "dsn=tt"
Copyright (c) 1996-2011, Oracle. All rights reserved.
Type ? or "help" for help, type "exit" to quit ttIsql.
connect "dsn=tt";
*836: Cannot create data store shared-memory segment, error 22*
The command failed.
Done
The exception in ttmesg.log
[oracle@ttnode1 info]$ tail -f ttmesg.log
2013-01-14 17:42:49.98 Warn: : 6533: TimesTen Daemon Release 11.2.2.4.0.tt started.
2013-01-14 17:42:59.45 Err : : 6533: TT14000: TimesTen daemon internal error: Error 22 creating shared segment, KEY 0x0200778b
2013-01-14 17:42:59.45 Err : : 6533: -- OS reports invalid shared segment size
2013-01-14 17:42:59.45 Err : : 6533: -- Confirm that SHMMAX kernel parameter is set > datastore size
2013-01-14 17:45:32.67 Warn: : 6533: request id check 'MKB9+MF7V7DybTjglCEC/10d5/N7FCEFtayvZF4a9xQ=' failed (-5)
2013-01-14 17:47:18.45 Warn: : 6533: request id check 'u6GF7bBtmRQCXKYMAWa7LhwCv1GtIG8HXdW0GLRLHEU=' failed (-5)
2013-01-14 17:47:41.62 Warn: : 6533: request id check 'nNAzUc/plNUStN85qP9htbsz/E5psODMEeRYLmE/n50=' failed (-5)
2013-01-14 23:15:34.58 Warn: : 8590: TimesTen Daemon Release 11.2.2.4.0.tt started.
2013-01-14 23:15:43.44 Err : : 8590: TT14000: TimesTen daemon internal error: Error 22 creating shared segment, KEY 0x02008294
2013-01-14 23:15:43.44 Err : : 8590: -- OS reports invalid shared segment size
2013-01-14 23:15:43.44 Err : : 8590: -- Confirm that SHMMAX kernel parameter is set > datastore size
2013-01-14 23:16:11.23 Warn: : 8590: request id check 'v4TJ+ZyP3KRvGxfkguLgxNyRUdtfw/MMFrvR2tWMUBk=' failed (-5)
2013-01-14 23:18:01.34 Warn: : 8590: request id check 'p4DVyvW75Fjlo3dQ5f8OFbk4qpolqj8gFyQhqfW4ekQ=' failed (-5)
2013-01-14 23:19:50.28 Warn: : 8590: request id check 'DPQ8gSYcljQtkuvx6ccI5a5OGcjXklItV4Mj3Cf0DmA=' failed (-5)
2013-01-14 23:41:01.97 Warn: : 8820: TimesTen Daemon Release 11.2.2.4.0.tt started.
*2013-01-14 23:41:10.10 Err : : 8820: TT14000: TimesTen daemon internal error: Error 22 creating shared segment, KEY 0x02008294*
*2013-01-14 23:41:10.10 Err : : 8820: -- OS reports invalid shared segment size*
*2013-01-14 23:41:10.10 Err : : 8820: -- Confirm that SHMMAX kernel parameter is set > datastore size*
2013-01-14 23:42:20.31 Warn: : 8820: request id check 'sHRtjK5AUKI/RYPN6Mf6ivOPeGVFysbXT4eU9dfBZPw=' failed (-5)
2013-01-14 23:43:24.14 Warn: : 8905: TimesTen Daemon Release 11.2.2.4.0.tt started.
2013-01-14 23:43:29.64 Err : : 8905: TT14000: TimesTen daemon internal error: Error 22 creating shared segment, KEY 0x02008294
2013-01-14 23:43:29.64 Err : : 8905: -- OS reports invalid shared segment size
2013-01-14 23:43:29.64 Err : : 8905: -- Confirm that SHMMAX kernel parameter is set > datastore size
Here is the OS setting.
*[oracle@ttnode1 ~]$ cat /etc/sysctl.conf*
# Kernel sysctl configuration file for Red Hat Linux
# For binary values, 0 is disabled, 1 is enabled. See sysctl(8) and
# sysctl.conf(5) for more details.
# Controls IP packet forwarding
net.ipv4.ip_forward = 0
# Controls source route verification
net.ipv4.conf.default.rp_filter = 1
# Do not accept source routing
net.ipv4.conf.default.accept_source_route = 0
# Controls the System Request debugging functionality of the kernel
kernel.sysrq = 0
# Controls whether core dumps will append the PID to the core filename
# Useful for debugging multi-threaded applications
kernel.core_uses_pid = 1
# Controls the use of TCP syncookies
net.ipv4.tcp_syncookies = 1
# Controls the maximum size of a message, in bytes
kernel.msgmnb = 65536
# Controls the default maxmimum size of a mesage queue
kernel.msgmax = 65536
# Controls the maximum shared segment size, in bytes
kernel.shmmax = 68719476736
# Controls the maximum number of shared memory segments, in pages
kernel.shmall = 4294967296
Here's the DSN setting
* Datastore configuration in sys.odbc.ini file*
*[oracle@ttnode1 info]$ grep -v ^# sys.odbc.ini | sed '/^ *$/d'
[ODBC Data Sources]
TT=TimesTen 11.2.2 Driver
[TT]
Driver=/home/oracle/TimesTen/tt/lib/libtten.so
DataStore=/home/oracle/TimesTen/tt/info/DStore/itt_11224
DatabaseCharacterSet=AL32UTF8
PermSize=128
TempSize=96
ReplicationApplyOrdering=0
ReplicationParallelism=4
LogBufParallelism=4
LogBufMB=32
LogFileSize=32
LogFlushMethod=2
*[ice@ttnode1 ~]$ cat /proc/meminfo*
MemTotal: 3865624 kB
MemFree: 2287936 kB
Buffers: 9744 kB
Cached: 189340 kB
SwapCached: 62588 kB
Active: 739244 kB
Inactive: 796816 kB
HighTotal: 0 kB
HighFree: 0 kB
LowTotal: 3865624 kB
LowFree: 2287936 kB
SwapTotal: 2031608 kB
SwapFree: 1755480 kB
Dirty: 316 kB
Writeback: 0 kB
AnonPages: 1310800 kB
Mapped: 24260 kB
Slab: 12952 kB
PageTables: 8712 kB
NFS_Unstable: 0 kB
Bounce: 0 kB
CommitLimit: 3964420 kB
Committed_AS: 2886040 kB
VmallocTotal: 34359738367 kB
VmallocUsed: 1616 kB
VmallocChunk: 34359736599 kB
HugePages_Total: 0
HugePages_Free: 0
HugePages_Rsvd: 0
Hugepagesize: 2048 kB
*[ice@ttnode1 ~]$ grep SwapTotal /proc/meminfo*
SwapTotal: 4128752 kB
Earlier the swap space was 2031608 KB, but snice it shuold be 1.5 times the physical memory, i bumped it up to its current value
*[oracle@ttnode1 info]$ ttstatus*
TimesTen status report as of Mon Jan 14 17:47:32 2013
Daemon pid 6533 port 53398 instance tt
TimesTen server pid 6550 started on port 53399
Accessible by group oinstall
End of report
*[oracle@ttnode1 info]$ ttversion*
TimesTen Release 11.2.2.4.0 (64 bit Linux/x86_64) (tt:53398) 2012-09-24T08:28:05Z
Instance admin: oracle
Instance home directory: /homankse/oracle/TimesTen/tt
Group owner: oinstall
Daemon home directory: /home/oracle/TimesTen/tt/info
Thanks,
Ved

Answer 1

Hi,
On continuing my debugging steps, if checked the limits for IPC facility.
ipcs -m -l
------ Shared Memory Limits --------
max number of segments = 4096
max seg size (kbytes) = 32768
max total shared memory (kbytes) = 8388608
min seg size (bytes) = 1
This says that "max number of segments = 4096", where as the kernel parameter is defined as "kernel.shmall = 4294967296".
Am i correct in understanding that "max number of segments" is same as "kernel.shmall" and the values should be same.
Also, it says that "max seg size (kbytes) = 32768" ie around 32MB, where as the kernel parameter is defined as "kernel.shmmax = 68719476736" i.e around 64BG.
and since, the DSN is requesting to create shared memory segment of 128MB, which is greater that 32MB(as per max seg size (kbytes) = 32768), Timesten is throwing the error.
Thanks everyone for helping me out.
_ved