Tuesday, December 7, 2010
Monday, December 6, 2010
heap dumps Out Of Memory
Out Of Memory
If you receive OOM error in the SystemOut.log.
First you take a thread dump, heap dump.
take 3 dumps each with wait time of 1 min.
analyze the dumps and you will know what, where and how you received the OOM.
Also check if you have recieved any other error message like Thread hung , ConnectionWait time...
Also is there any other process that using lot of system resorce?
Check the Top and Sar -a command. it will give you memory usage on the system.
enable Verbose GC, for better memory management.
If you receive OOM error in the SystemOut.log.
First you take a thread dump, heap dump.
take 3 dumps each with wait time of 1 min.
analyze the dumps and you will know what, where and how you received the OOM.
Also check if you have recieved any other error message like Thread hung , ConnectionWait time...
Also is there any other process that using lot of system resorce?
Check the Top and Sar -a command. it will give you memory usage on the system.
enable Verbose GC, for better memory management.
heap dumps
To enable automated heap dump generation support, perform the following steps in the administrative console: (heap dump will generated upon receiving the out.of.memory exceptios)
1. Click Servers > Application servers in the administrative console navigation tree.
2. Click server_name >Runtime Performance Advisor Configuration.
3. Click the Runtime tab.
4. Select the Enable automatic heap dump collection check box.
5. Click OK.
Generating Manually
use kill -3 PID on unix/linux machines.
Invoke the generateHeapDump operation on a JVM MBean, for example,
* Finding JVM objectName:
<wsadmin> set objectName [$AdminControl queryNames WebSphere:type=JVM,process=<servername>,
* Invoking the generateHeapDump operation on JVM MBean:
<wsadmin> $AdminControl invoke $objectName generateHeapDump
heap dumps can be found under profile_root\profile-name with naming heapdump.<date>..<timestamp><pid>.phd
Use HeapAnalyzer or MDD4J for analyzing heap dumps
1. Click Servers > Application servers in the administrative console navigation tree.
2. Click server_name >Runtime Performance Advisor Configuration.
3. Click the Runtime tab.
4. Select the Enable automatic heap dump collection check box.
5. Click OK.
Generating Manually
use kill -3 PID on unix/linux machines.
Invoke the generateHeapDump operation on a JVM MBean, for example,
* Finding JVM objectName:
<wsadmin> set objectName [$AdminControl queryNames WebSphere:type=JVM,process=<servername>,
* Invoking the generateHeapDump operation on JVM MBean:
<wsadmin> $AdminControl invoke $objectName generateHeapDump
heap dumps can be found under profile_root\profile-name with naming heapdump.<date>..<timestamp><pid>.phd
Use HeapAnalyzer or MDD4J for analyzing heap dumps
Migrating to a Version 6.1 application server using the Migration wizard
http://publib.boulder.ibm.com/infocenter/wasinfo/v6r1/index.jsp?topic=/com.ibm.websphere.express.doc/info/exp/ae/tmig_wizto61sas.html
transfer a file from one system to another remote system
how to check remote server? and how to transfer a file from one system to another remote system?
To check the remote server .. u can just
ping ipaddress
To test a perticular port
Telnet ipaddress portno
---------------------
To transfer a file from one unix machine to another unix machine u can use
scp command
scp < files to transfer > remoter server ipaddress:/dir
you can see the help to provide the varios option in scp command
if you want to transfer file from windows to unix u can use the winscp utility
To check the remote server .. u can just
ping ipaddress
To test a perticular port
Telnet ipaddress portno
---------------------
To transfer a file from one unix machine to another unix machine u can use
scp command
scp < files to transfer > remoter server ipaddress:/dir
you can see the help to provide the varios option in scp command
if you want to transfer file from windows to unix u can use the winscp utility
Configuring SSL for WebSphere and IBM Http Server
http://josephamrithraj.wordpress.com/2010/09/01/configuring-ssl-for-websphere-and-ibm-http-server-part1of2/
http://josephamrithraj.wordpress.com/2010/11/10/configuring-ssl-for-websphere-and-ibm-http-server-part2of2/
http://publib.boulder.ibm.com/infocenter/iseries/v5r3/index.jsp?topic=%2Frzatz%2F51%2Fsec%2Fsecjsswa.htm
http://www.redbooks.ibm.com/redbooks/pdfs/sg246316.pdf
http://josephamrithraj.wordpress.com/2010/11/10/configuring-ssl-for-websphere-and-ibm-http-server-part2of2/
http://publib.boulder.ibm.com/infocenter/iseries/v5r3/index.jsp?topic=%2Frzatz%2F51%2Fsec%2Fsecjsswa.htm
http://www.redbooks.ibm.com/redbooks/pdfs/sg246316.pdf
Performace Issue
Scenario1: We have servers in US and Indian users are saying there is a performance issue accessing the servers in US, now how do you resolve and what log files you will look into?
Performance issue can be due to many reasons
1) Network
2) Webserver
3) Appserver
4) DB
5) Hardware
The common steps to troubleshoot are to identify where is the performance issue
1) Try to access the url from ur system to identity if is not specif to the users
2) Try ping to the webserver to see if there is any network latency
3) See the access & error logs of webservers
4) check the appservers logs like systemout and systemerr to see if there are any OOM and hung threads ( if yes troubleshoot it accordingly
5) Check the plugin log to see if there are too many users accessing and there are few connection confiured between the webserver and appserver
6) Check the connections to the DB .. is it maxed out
7) check the cpu and memory utilisation of the system
Scenario2: If you have to federate a Application Server to DMGR in US, how will you do it, what parameters to look for?
Federation will be same whereever they are located but there are some checklist
1) Most imp -- ensure that the firewall ports ( all the 8-10 ports) between the dmgr and the appsever are opened bothways .. otherwise u will not be able to federate it
2)Ensure that the DMGR is running
3) appropriate permissions are given
4) once above is validated then execute the ./addNode.sh dmgr_ip port -user adfdf -password 34324
Performance issue can be due to many reasons
1) Network
2) Webserver
3) Appserver
4) DB
5) Hardware
The common steps to troubleshoot are to identify where is the performance issue
1) Try to access the url from ur system to identity if is not specif to the users
2) Try ping to the webserver to see if there is any network latency
3) See the access & error logs of webservers
4) check the appservers logs like systemout and systemerr to see if there are any OOM and hung threads ( if yes troubleshoot it accordingly
5) Check the plugin log to see if there are too many users accessing and there are few connection confiured between the webserver and appserver
6) Check the connections to the DB .. is it maxed out
7) check the cpu and memory utilisation of the system
Scenario2: If you have to federate a Application Server to DMGR in US, how will you do it, what parameters to look for?
Federation will be same whereever they are located but there are some checklist
1) Most imp -- ensure that the firewall ports ( all the 8-10 ports) between the dmgr and the appsever are opened bothways .. otherwise u will not be able to federate it
2)Ensure that the DMGR is running
3) appropriate permissions are given
4) once above is validated then execute the ./addNode.sh dmgr_ip port -user adfdf -password 34324
Wednesday, December 1, 2010
Websphere Administrator/Senior Websphere Administrator job details
Experience with administering WebSphere Application Server Network Deployment (ND) 5.x and 6.x.
? Experience with WAS ND Installation and application deployment.
. Experience in Performance Tuning of Websphere application
? Experience with the SunOne (iPlanet), Apache web servers.
. Proficient in Solaris or Linux or other unix variants.
? Experience with scripting (shell, Jython, JACL)
? Excellent communication (written and oral)
? Excellent documentation skills.
? J2EE Framework knowledge.
. Ability to work in 24X7 model.
? Experience with troubleshooting production applications.
Desired:
? Exposure to load balancing tools (BigIP, WAS plug-ins) and Siteminder.
? Understanding of applications integrated into a DMZ.
? Desired experience working in on high volume systems
? Desired experience working with remote and multi-site deployments
Roles & Responsibilities:
? Code installations ? Application code deployments in all environments
. Troubleshooting Production / Staging & Development applications.
? Documentation
? Change process support ? Opening/closing tickets, tracking
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