Question one:
Just enter the home page, or refresh, the magic of love has been going round in circles.
Investigation method:
(A), the request is not sent to the server
1, the load machine problem (cpu, disks, memory)
2, network problems
(B), the request sent to the server, the server may be a problem during the processing or return
1, the application server cpu, disk, memory, network
2, the database server cpu, disk, memory, network
3, database connection pool queue
4, application code issues
5, sql statement execution is slow, inefficient
6, JVM stack overflow, frequently gc
7, middleware thread pool queue
The investigation process:
1, can request access to the original page tomcat, and the beginning of the page you can see the data, sends a request proof load is no problem.
2, the load machine can ping ping server, view the network is no problem.
3, tcp server, ip connection
2, top, free to view application server and database server cpu, disk and memory is no problem.
3, ping, view the network is no problem.
4, the database connection pool to see if there is idle: Show Status like 'Threads%' ;
Whether 5, and other middleware monitoring tomcat connection pool is full, direct look at the monitor tomcat.
6, see the sql statement execution time: show profiles;
7, JVM, see gc situation: # jstat -gcutil 8071 3000
View thread stack problem jstack 8071> 1.log