Yesterday's implementant feedback: After starting WebLogic, you cannot enter the console, IE display blank page, and even the login interface is not!
Others remote login server access, indeed, see WebLogic's related files, depressed, no error, the problem is the hardest problem. Since the system is running, you cannot restart the service. Best can't feel that only the Internet is found to find relevant information. Later I found the following article:
After starting WebLogic, you cannot enter the console and application.
This is an abnormal weird problem. It is also the most strangely solved problem I have encountered. Our system is in the trial operation stage, and occasionally there will be no way to log in. At the same time, WebLogic's console cannot land. . However, view the process in the operating system, WebLogic's process is still, the application's background output, and the WEBLOGIC's log file output has no error message.
At the beginning, the system has problems, we will restart the system and can always solve the problem. Occasionally, the phenomenon of restarting twice can solve the problem. I also contacted the engineers of BEA. They provide a variety of solutions. For example, when there is a problem, use the Telnet IP Port whether it can be connected to the app, such as using Kill -3, print DUMP Information, send them to see reasons, etc., etc., eventually failed to solve this problem. The longest once caused our application for 2 hours.
Later, there was no such problem for some time. However, a sudden problem suddenly again, and this time, it was basically reached a whole day, the system could not access it. We use the method of rebuilding WebLogic Domain and Server to modify the way to log in to the port. Every time I persist, I will have problems again. More serious is that after rebooting WebLogic, the system can not access it immediately. I even thought that it was not a problem with WebLogic software, almost wanted to use WebSphere to replace it.
Later, we use VPN's way to let BEA engineers land in the system to view the reasons, but their 800 engineers have not found the reason, depressed and I am. When the Guangzhou Pre-sales engineer happens to view the system, there is a connection between more than 70 states to SYN_RCVD in the system. This contacts malicious DOS attacks. (Http://www-900.ibm.com/developerworks/cn/security/se-ddos/index.shtml)
After testing, this is the cause. NetStat -an | GREP SYN | WC -L The number of times each display is only greater than 70, the system is basically unacceptable. Later, we filled this problem through two firewalls (a connection to internal networks, an access to internal network).
This problem plagues me for a long time and tested various methods. It is mainly written here, mainly to explain two problems. First: When excluding the system failure, we must first take into account the problem of network and viruses. Second: When we exclude system problems, we have not used all network connections to disconnecting the server, this machine access system, if this approach is used, problems can be found earlier. Third: This problem that does not have any wrong prompts is the most difficult to find, everyone should be careful.
The above black body is taken from Java free people
After reading this, the heart is a lot, if so, the restart system should be fine. However, you must strengthen the security settings of the server.
