The following tuning considerations are based on the tuning of various test deployments. Because each deployment is unique, you might need further customization and interactive testing to satisfy your specific requirements.
It is highly recommended that you apply the latest Access Manager 7 2005Q4 patch, available for both Solaris SPARC and Solaris x86 systems. You can request this patch from your Sun Microsystems technical representative.
The Access Manager 7 2005Q4 patch resets the LDAP connection values in the /etc/opt/SUNWam/config/serverconfig.xml file to their default values. Therefore, be sure to apply this patch before you run the amtune-identity script.
For Solaris SPARC systems with CMT processor with CoolThreads technology, in the /etc/opt/SUNWam/config/AMConfig.properties file, it is recommended that you add the following properties at the end of the file:
where value depends on the number of cores in a Sun Fire T1000 or T2000 server. For example, for 8 cores, set value to 8, or for 6 cores, set value to 6.
To tune for maximum performance on Linux systems, you need to make tuning adjustments to the following items:
If you are running Application Server 8.1 on Red Hat Linux, the stack size of the threads created by the Red Hat OS for Application Server is 10 Mbytes, which can cause JVM resource problems (CR 6223676). To prevent these problems, set the Red Hat OS operating stack size to a lesser value such as 2048 or even 256 Kbytes, by executing the ulimit command before you start Application Server. Execute the ulimit command on the same console that you will use to start Application Server. For example:
ulimit -s 256
You might need to increase the number of file descriptors from the default. Having a higher number of file descriptors ensures that the server can open sockets under high load and not abort requests coming in from clients. Start by checking system limits for file descriptors with this command:
cat /proc/sys/fs/file-max 8192
The current limit shown is 8192. To increase it to 65535, use the following command (as root):
echo "65535" > /proc/sys/fs/file-max
To make this value to survive a system reboot, add it to /etc/sysctl.conf and specify the maximum number of open files permitted:
fs.file-max = 65535
Note: The parameter is not proc.sys.fs.file-max, as you might expect.
To list the available parameters that can be modified using sysctl:
To load new values from the sysctl.conf file:
sysctl -p /etc/sysctl.conf
To check and modify limits per shell, use the following command:
The output will look something like this:
cputime unlimited filesize unlimit datasize unlimited stacksize 8192 kbytes coredumpsize 0 kbytes memoryuse unlimited descriptors 1024 memorylocked unlimited maxproc 8146 openfiles 1024
The openfiles and descriptors show a limit of 1024. To increase the limit to 65535 for all users, edit /etc/security/limits.conf as root, and modify or add the nofile setting (number of file) entries:
* soft nofile 65535 * hard nofile 65535
The asterisk (*) is a wildcard that identifies all users. You could also specify a user ID instead.
Then edit /etc/pam.d/login and add the line:
session required /lib/security/pam_limits.so
On Red Hat Linux , you also need to edit /etc/pam.d/sshd and add the following line:
session required /lib/security/pam_limits.so
On many systems, this procedure will be sufficient. Log in as a regular user and try it before doing the remaining steps. The remaining steps might not be required, depending on how pluggable authentication modules (PAM) and secure shell (SSH) are configured.
To change virtual memory settings, add the following to /etc/rc.local:
echo 100 1200 128 512 15 5000 500 1884 2 > /proc/sys/vm/bdflush
For more information, view the man pages for bdflush.
To ensure that the network interface is operating in full duplex mode, add the following entry into /etc/rc.local:
mii-tool -F 100baseTx-FD eth0
where eth0 is the name of the network interface card (NIC).
To tune disk I/O performance for a non-SCSI disk, follow these steps:
Test the disk speed with this command:
/sbin/hdparm -t /dev/hdX
Enable direct memory access (DMA) with this command:
/sbin/hdparm -d1 /dev/hdX
Check the speed again using the hdparm command. Given that DMA is not enabled by default, the transfer rate might have improved considerably. In order to do this at every reboot, add the /sbin/hdparm -d1 /dev/hdX line to /etc/conf.d/local.start, /etc/init.d/rc.local, or whatever the startup script is called.
To tune the TCP/IP settings, follow these steps:
Add the following entry to /etc/rc.local:
echo 30 > /proc/sys/net/ipv4/tcp_fin_timeout echo 60000 > /proc/sys/net/ipv4/tcp_keepalive_time echo 15000 > /proc/sys/net/ipv4/tcp_keepalive_intvl echo 0 > /proc/sys/net/ipv4/tcp_window_scaling
Add the following to /etc/sysctl.conf:
# Disables packet forwarding net.ipv4.ip_forward = 0 # Enables source route verification net.ipv4.conf.default.rp_filter = 1 # Disables the magic-sysrq key kernel.sysrq = 0 net.ipv4.ip_local_port_range = 1204 65000 net.core.rmem_max = 262140 net.core.rmem_default = 262140 net.ipv4.tcp_rmem = 4096 131072 262140 net.ipv4.tcp_wmem = 4096 131072 262140 net.ipv4.tcp_sack = 0 net.ipv4.tcp_timestamps = 0 net.ipv4.tcp_window_scaling = 0 net.ipv4.tcp_keepalive_time = 60000 net.ipv4.tcp_keepalive_intvl = 15000 net.ipv4.tcp_fin_timeout = 30
Add the following as the last entry in /etc/rc.local:
sysctl -p /etc/sysctl.conf
Reboot the system.
Use this command to increase the size of the transmit buffer:
tcp_recv_hiwat ndd /dev/tcp 8129 32768
Consider making the following changes in the WebSphere Administrative Console:
For more information, see the “IBM WebSphere V5.1 Performance, Scalability, and High Availability WebSphere Handbook Series” at:
Add the JVM tuning parameters shown below, by following these links in the console:
Servers>Application Servers>server1>Process Definition>Java Virtual Machine
Add “-server” as the first parameter in the “Generic JVM arguments” box. Then, add the following entries after the other existing parameters:
-XX:NewSize=336M -XX:MaxNewSize=336M -XX:+DisableExplicitGC -XX:+UseParNewGC -XX:+UseConcMarkSweepGC -XX:+CMSPermGenSweepingEnabled -XX:+UseCMSCompactAtFullCollection -XX:CMSFullGCsBeforeCompaction=0 -XX:+CMSClassUnloadingEnabled -XX:SoftRefLRUPolicyMSPerMB=0 -XX:+PrintClassHistogram -XX:+PrintGCTimeStamps -Xloggc:/opt/WebSphere/AppServer/logs/server1/gc.log -XX:-CMSParallelRemarkEnabled
Make sure that servlet caching is enabled by checking the checkbox next to “Enable servlet caching” by following these links in the console:
Application Servers>server1>Web Container>Configuration: Servlet caching
Allow the thread pool to grow beyond the maximum thread pool size set by checking the checkbox next to “Allow thread allocation beyond maximum thread size” by following these links:
Application Servers>server1>Web Container>Thread Pool Is Growable
Consider making the following changes:
For BEA WebLogic Server 8.1 SP4, to avoid the java.lang.OutofMemoryError reported by the WebLogic JVM 1.4.2_05, add the following JVM GC (garbage collection) parameter in the startWebLogic.sh JAVA_OPTIONS:
Set this parameter in addition to the other heap size and GC parameters that have been added for JVM 1.4.2 and 1.5.0 for Application Server 8.1 and Web Server 6.1.
For example, if Access Manager is installed in the default user_projects location (/usr/local/bea/user_projects/domains/mydomain/startWebLogic.sh):
JAVA_OPTIONS="-XX:+DisableExplicitGC -XX:+UseParNewGC -XX:+UseConcMarkSweepGC -XX:+CMSPermGenSweepingEnabled -XX:+UseCMSCompactAtFullCollection -XX:CMSFullGCsBeforeCompaction=0 -XX:+CMSClassUnloadingEnabled -XX:-CMSParallelRemarkEnabled -XX:SoftRefLRUPolicyMSPerMB=0 -XX:+PrintClassHistogram -XX:+PrintGCTimeStamps -Xloggc:/usr/local/bea/user_projects/domains/mydomain/myserver/gc.log"
Modify the commonEnv.sh script in the /usr/local/bea/weblogic81/common/bin directory for heap size increases in the section where $PRODUCTION_MODE" = "true" (which should be set to true, before running Access Manager in /usr/local/bea/user_projects/domains/mydomain/startWebLogic.sh):
# Set up JVM options base on value of JAVA_VENDOR if [ "$PRODUCTION_MODE" = "true" ]; then case $JAVA_VENDOR in BEA) JAVA_VM=-jrockit MEM_ARGS="-Xms128m -Xmx256m" ;; HP) JAVA_VM=-server MEM_ARGS="-Xms32m -Xmx200m -XX:MaxPermSize=128m" ;; IBM) JAVA_VM= MEM_ARGS="-Xms32m -Xmx200m" ;; Sun) JAVA_VM=-server MEM_ARGS="-Xms2688M -Xmx2688M -XX:NewSize=336M -XX:MaxNewSize=336M" # MEM_ARGS="-Xms32m -Xmx200m -XX:MaxPermSize=128m"
Set the Execute Queue Thread count to be more than the number of CPUs. For example, consider using a value that is twice the number of CPUs. Set this value in either the console or in the /usr/local/bea/user_projects/domains/mydomain/config.xml file:
<ExecuteQueueName="MyExecute Queue" ThreadCount="8" ThreadsIncrease="4"/>
For more information, see “Modifying the Default Thread Count” in “WebLogic Server Performance and Tuning” at:
A guideline for setting Connection Backlog Buffering is 8192 for a server with 4 Gbytes of physical memory (which is equivalent to the ConnectionQueue size tuning set in the Sun Java System Web Server 6.1 magnus.conf file).
For more information, see “Tuning Connection Backlog Buffering” in the “WebLogic Server Performance and Tuning” document at: