There are many reasons that could lead to the users experiencing slowness, by understanding the root cause of the system slowness, we will be able to troubleshoot effectively. In order to resolve the problems effectively, it is extremely important for the users to provide the details. To some users, slow means if a page is loaded more than 2 seconds, while slowness could mean 20 seconds for the same page to be loaded. Instead of using qualitative words (big , small, slow, fast, good, not good), we will use quantitative words while communicating with the engineers who is going to help you in seconds, minutes, hours, date / time etc. Also, in order to be specific, we are going to indicate which page is slow, and which page (function / screen / module) takes how many seconds to load, and how many seconds to generate a certain report. And if we are generating the report, we will indicate exactly which date range, which branches / company, what category filter or settings we use to generate the reports. All this information is essential for us to help you identify the root cause quickly, and resolve the problems effectively.
Possible Root Cause of the System Slowness, Detection, and Solutions
| No | Possible Root Cause | Troubleshooting Guide | Solutions |
|---|---|---|---|
| 1 | Client Device
| The fastest way to check if the slowness is caused by the client device, is to access the same website / functions with multiple other devices. If Accessibility from other devices are normal, then the probability of slowness caused by the slowness in the device itself is almost certain. Regardless of whether it is mobile or desktop devices, see below for more steps to identify the root cause:
Apart from System Performance monitoring, it is never alien to our technical support team that some of the client devices that have been infected by Virus is known to perform badly. Usually, when we detected high CPU usage, and high Network Bandwidth, we would also be recommending the users to install anti-virus software to detect the potential security threat to the devices. Another possibility is the web browser. When it comes to web-browser usage, settings, the following areas could be checked:
| Depends on the root cause from the troubleshooting of the client device, users could upgrade the RAM, Processor, or perform anti-virus scanning accordingly. At the time of reading, the following guide may be out-dated, but google is your best friends, there are plenty of resources available online to resolve the problems that you are having with optimizing your devices.
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| 2 | Client Local Area Network | When devices are not connected directly to the internet, it is possible it goes thru routers, switches, proxy servers and other possible network routes to access the Wavelet EMP on the cloud. There are a few ways to check and detect if the problems are caused by the Local Area Network:
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| 3 | Client Internet Connectivity | On the client side, for easier troubleshoot. Please ask customer to use right tools such as Teamviewer. Top 3 reasons from client side
| Troubleshoot Internet connection problems |
| 4 | Public Internet | If you are connected from "Public Internet", you might experienced having difficulties of accessing URL which causes by:
| Refer to this wiki for solutions |
| 5 | Data Center Network | Always refer to complete server list https://docs.google.com/spreadsheets/d/1nfHlOJYQhhxe_aMSOLJd6zC1cL9dptmPPf8t7zMwllE/edit#gid=0
| Need to ask from data center
AWS confluences: http://intranet.wavelet.asia/projects/cloud-amazon/wiki/Launching_new_EMP_instance_on_Amazon /wiki/spaces/WU/pages/36798614 /wiki/spaces/WU/pages/22839391 /wiki/spaces/WU/pages/28803771 Azure confluences: /wiki/spaces/WU/pages/11567303
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| 6 | Server Network | For AWS server network, you may click the instance -> monitoring. Refer to network in and network out graph and observer
| If the network out too high, use netstat to observe which IP that causing high network out. kill and chmod the process will help |
| 7 | Server Operating Systems | Server Operating Systems : Ubuntu, Centos, Amazon Linux AMI | Useful LINUX command http://www.tecmint.com/useful-linux-commands-for-system-administrators/ The different between Ubuntu and Centos Ubuntu : apt-get Centos : yum |
| 8 | Server Application Server | Refer to Ubuntu and EMP installation guide to back to basic /wiki/spaces/WU/pages/11568251 Basic Checking for server slow http://intranet.wavelet.asia/projects/tech/wiki/Trouble_Shoot_Server_Slow__Unresponsive http://intranet.wavelet.asia/projects/tech/wiki/Server_Slow_Issue Missing run.sh and shutdown.sh Auto add run.sh and shutdown.sh using rc.local script
Out of memory error http://intranet.wavelet.asia/projects/tech/wiki/Out_of_memory_error_--_javalangOutOfMemoryError
| as root Check running process using these command and observe showlog : Output the running server log top : List processes running on the system free -m : check RAM size ps aux|grep jboss : Process status of jboss jboss-stop : to stop server /etc/init.d/postgresql-9.2.4 restart : to restart postgres jboss-start : to start server reboot : to reboot the server
Useful wiki http://intranet.wavelet.asia/projects/tech/wiki/JBoss_ http://intranet.wavelet.asia/projects/tech/wiki/JBoss_configurations http://intranet.wavelet.asia/projects/tech/wiki/Connection_Pool_size |
| 9 | Server Database Server | If you are not able to connect to the wsemp database, most probably your postgres has not started yet. run command as root, /etc/init.d/postgresql-9.2.4 start and try psql command | common error is when postgres cannot start as postmasterpid has invalid data |
| 10 | Server Hard Disk | Run this command df -h If the usage is more thatn 90%, you need to clear up some data by finding it using command find / -type f -size +20M -exec ls -lh {} \; | awk '{ print $NF ": " $5 }'Note: Don't delete anything inside /var/lib/pgsql/data, we stored database inside that folder. It's normal for that folder have big size | In same cases, HDD 100% caused by /var/log/cups/ |
| 11 | Wavelet EMP Itself | Modules is missing Menu toolbar missing after reboot (occurring in 2.1.20150911 or later revision) System Patches (null pointer exception) ( check server log) and get help from programmer to debug the null pointer exception
| Check the server log using vim command vim /usr/java/jboss/server/default/log/server.log |
| 12 | Usage of EMP | Heavy usage of EMP from customer : Need to find out which report and who is generating and communicate with customer about the usage of report. The usage of query checking running process would be useful to find out the specific report
| To check Queries to check running processes http://intranet.wavelet.asia/projects/tech/wiki/Queries_to_check_running_processes
If jboss-stop doesn't run anything use ps aux|grep java kill -9 2304
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