httpclient 的性能问题总结

1、Too many open files

java.net.SocketException: Too many open files
at java.net.Socket.createImpl(Unknown Source)
at java.net.Socket.connect(Unknown Source)
at org.apache.http.conn.scheme.PlainSocketFactory.connectSocket(PlainSocketFactory.java:123)

严重: Endpoint ServerSocket[addr=0.0.0.0/0.0.0.0,port=0,localport=80] ignored exception: java.net.SocketException: Too many open files
java.net.SocketException: Too many open files
at java.net.PlainSocketImpl.socketAccept(Native Method)

网络中查询有说是linux的文件打开数超过了默认的1024个文件，具体查看linux下面的文件打开最大值的命令ulimit -a，出现信息如下：

core file size          (blocks, -c) 0
data seg size           (kbytes, -d) unlimited
scheduling priority             (-e) 0
file size               (blocks, -f) unlimited
pending signals                 (-i) 69631
max locked memory       (kbytes, -l) 32
max memory size         (kbytes, -m) unlimited
open files                      (-n) 1024
pipe size            (512 bytes, -p) 8
POSIX message queues     (bytes, -q) 819200
real-time priority              (-r) 0
stack size              (kbytes, -s) 10240
cpu time               (seconds, -t) unlimited
max user processes              (-u) 69631
virtual memory          (kbytes, -v) unlimited
file locks                      (-x) unlimited

其中open files                      (-n) 1024 默认为1024，网络中有说解决方法是加大文件打开的最大值，ulimit -n 8192，此命令未测试；

但是由于Httpclient引起的。当并发访问量过大的时候，这个方法只是治标不治本的。所有还是解决Httpclient远程请求所造成Socket没有释放,HttpClient本身存在这个问题。

     HttpClient client = new HttpClient();
        client.getParams().setBooleanParameter("http.protocol.expect-continue", false);
        PostMethod post = new PostMethod(Config.getValue("msg_url"));
        post.addRequestHeader("Connection", "close");

 

2、多线程

 

HttpClient client = new HttpClient(); client 不能设置成公用静态的变量来重复使用