workman strace busy进程

追踪结果如下：

rt_sigreturn({mask=[]}) = 45
11:17:51.166205 recvfrom(6, 0x7f8dbea58018, 655350, 0, NULL, NULL) = ? ERESTARTSYS (To be restarted if SA_RESTART is set)
11:17:52.166381 --- SIGUSR2 {si_signo=SIGUSR2, si_code=SI_USER, si_pid=18243, si_uid=0} ---
11:17:52.166429 rt_sigreturn({mask=[]}) = 45
11:17:52.166525 recvfrom(6, 0x7f8dbea58018, 655350, 0, NULL, NULL) = ? ERESTARTSYS (To be restarted if SA_RESTART is set)
11:17:53.169452 --- SIGUSR2 {si_signo=SIGUSR2, si_code=SI_USER, si_pid=18243, si_uid=0} ---
11:17:53.169524 rt_sigreturn({mask=[]}) = 45
11:17:53.169612 recvfrom(6, 0x7f8dbea58018, 655350, 0, NULL, NULL) = ? ERESTARTSYS (To be restarted if SA_RESTART is set)
11:17:54.169915 --- SIGUSR2 {si_signo=SIGUSR2, si_code=SI_USER, si_pid=18243, si_uid=0} ---
11:17:54.169967 rt_sigreturn({mask=[]}) = 45
11:17:54.170040 recvfrom(6, 0x7f8dbea58018, 655350, 0, NULL, NULL) = ? ERESTARTSYS (To be restarted if SA_RESTART is set)
11:17:55.167907 --- SIGUSR2 {si_signo=SIGUSR2, si_code=SI_USER, si_pid=18243, si_uid=0} ---
11:17:55.168112 rt_sigreturn({mask=[]}) = 45
11:17:55.168265 recvfrom(6, 0x7f8dbea58018, 655350, 0, NULL, NULL) = ? ERESTARTSYS (To be restarted if SA_RESTART is set)
11:17:56.170834 --- SIGUSR2 {si_signo=SIGUSR2, si_code=SI_USER, si_pid=18243, si_uid=0} ---
11:17:56.170961 rt_sigreturn({mask=[]}) = 45
11:17:56.171059 recvfrom(6, 0x7f8dbea58018, 655350, 0, NULL, NULL) = ? ERESTARTSYS (To be restarted if SA_RESTART is set)
11:17:57.171275 --- SIGUSR2 {si_signo=SIGUSR2, si_code=SI_USER, si_pid=18243, si_uid=0} ---
11:17:57.171352 rt_sigreturn({mask=[]}) = 45
11:17:57.171414 recvfrom(6, 0x7f8dbea58018, 655350, 0, NULL, NULL) = ? ERESTARTSYS (To be restarted if SA_RESTART is set)
11:17:58.172128 --- SIGUSR2 {si_signo=SIGUSR2, si_code=SI_USER, si_pid=18243, si_uid=0} ---
11:17:58.172193 rt_sigreturn({mask=[]}) = 45
11:17:58.172242 recvfrom(6, 0x7f8dbea58018, 655350, 0, NULL, NULL) = ? ERESTARTSYS (To be restarted if SA_RESTART is set)
11:17:59.172539 --- SIGUSR2 {si_signo=SIGUSR2, si_code=SI_USER, si_pid=18243, si_uid=0} ---
11:17:59.172634 rt_sigreturn({mask=[]}) = 45
11:17:59.172709 recvfrom(6, 0x7f8dbea58018, 655350, 0, NULL, NULL) = ? ERESTARTSYS (To be restarted if SA_RESTART is set)
11:18:00.172508 --- SIGUSR2 {si_signo=SIGUSR2, si_code=SI_USER, si_pid=18243, si_uid=0} 

请问下，这是什么问题？
利用lsof -nPp -pid的话，显示最后一步是访问别的服务器的3306端口来着