The application at the time of visit between 503 ServiceUnavailable frequent;

Modify appach2 parameters and so on, the problem still exists;

Later on the server side curl background simulation access and occasionally succeed, fail occasionally, unstable;

Then use Telnet IP PORT, the same server sample appear unstable and connected to the success and failure;

During the network and application has not been change, consult, need from which several aspects of screening

Among them:
Routetrace information is as follows:

SJKTK8808PDWFMPXYDMZSV1: ~ # traceroute 10.17.7.185
Traceroute to 10.17.7.185 (10.17.7.185), 30 hops Max, 40 byte packets using UDP
Unable to look up 10.9.216.1: Temporary failure in the name resolution
1 10.9.216.1 4.726 ms 4.221 ms 3.860 ms
Unable to look up 172.16.4.2: Temporary failure in the name resolution
2 * 172.16.4.2 1.505 ms 1.381 ms
Unable to look up 172.16.100.157: Temporary failure in the name resolution
Unable to look up 172.16.100.53: Temporary failure in the name resolution
3 172.16.100.157 0.762 ms 0.807 ms 172.16.100.53 3.548 ms
Unable to look up 172.16.100.2: Temporary failure in the name resolution
4 172.16.100.2 1.006 ms 0.895 ms 0.947 ms
Unable to look up 172.16.100.226: Temporary failure in the name resolution
5 172.16.100.226 8.040 ms 8.252 ms 8.426 ms