An example of Oracle Optimization Based on Solaris

I. High cluster wait time problems in RAC

1. Set the LMS process to FX 60. Do not adjust the number of lms processes too much.

Note: process priority can be set after Solaris 10 Update 10 and Solaris 11. You can view the/etc/release Version. For example, Oracle Solaris 10 1/13 indicates Solaris 10 Update 11. For details, refer to: Oracle Solaris 10 Update version and its history.

Oracle Solaris 10 1/06 (Update 1) U1
Oracle Solaris 10 6/06 (Update 2) U2
Oracle Solaris 10 11/06 (Update 3) U3
Oracle Solaris 10 8/07 (Update 4) U4
Oracle Solaris 10 5/08 (Update 5) U5
Oracle Solaris 10 10/08 (Update 6) U6
Oracle Solaris 10 5/09 (Update 7) U7
Oracle Solaris 10 10/09 (Update 8) U8
Oracle Solaris 10 9/10 (Update 9) U9
Oracle Solaris 10 8/11 (Update 10) U10
Oracle Solaris 10 1/13 (Update 11) U11

2. UDP parameters:

In/etc/system
Set ip: ip_squeue_bind = 0

2. In large systems, startup is slow and sga loading is slow.

1. to accelerate the loading of sga memory, you can increase the mode of concurrent loading of memory: (Note: The default value is a maximum of 16 concurrency, and the following is changed to 32 concurrency), modify the parameters in/etc/system:
Set vmtask_ntasks_max = 0x20
2. Or directly modify it online:
Echo "vmtask_ntasks_max/W 0x20" |/bin/mdb-kw
In the test environment, on the T3-4 machine, load the slave g sga, if the default 16 concurrency, it takes 60 seconds, if you use 64 concurrency, it only takes about 20 seconds.

3. log file sync

Log file sync waits a lot, but log file parallel write does not have much waiting time.

You can use prstat-p-v to check the cpu usage of lgwr, such as the ratio of % sys, such as the latency of LAT.

1. Reduce the number of processes for each semaphore:
# Projadd-U oracle-K "process. max-sem-nsems = (priv, 64, deny)" user. oracle
# Projmod-a-K "process. max-sem-nsems = (priv, 64, deny)" user. oracle
# Prctl-n process. max-sem-nsems-r-v 64-I process <PID>
2. Increase the lgwr process priority to FX 60
# Priocntl-c FX-m 60-p 60-s '/usr/bin/pgrep-f ora_lgwr'
3. Use the cpu exclusively for lgwr
# Create Processor Set
# Psrset-c 56-63
# Turn off all but one CPU in the processor set
# Psradm-f 57-63
# Bind the lgwr to the processor set
# Psrset-B 1 'pgrep-f ora_lgwr'
# Mark the CPU as non-interruptible
# Psrset-f 56

4. db file sequential/parallel read too high.

1. Use processor sets to exclusively occupy the CPU.
2. Confirm that IO is evenly distributed on each available controllers/channels/ports.
3. In the SAN environment, consider using multi-path MPXIO
4. Use Database Smart Flash Cache:
-Db_flash_cache_file = <+ flashdg/FlashCacheFile>
-Db_flash_cache_size = <flash pool size>