Nginx502错误原因和解决方法总结
第一篇：Nginx 502错误原因和解决方法总结
Nginx 502错误原因和解决方法总结
【来源：小鸟云计算】
Ps.小鸟云，国内专业的云计算服务商
一.前沿
不管你是做运维还是做开发，哪怕你是游客，时不时会遇到502 Bad Gateway或504 Gateway Time-out。出现这页面，把服务重启下，再实在不行重启下服务器，问题就解决了，但是，这问题还是会困扰着你。夜黑风高正酣睡时，一个电话响起，让你重启服务或IISRESET，肯定是极大不爽，本文总结502与504故障分析与解决方法。
take up什么意思二.状态码解释
502 Bad Gateway：作为网关或者代理工作的服务器尝试执行请求时，从上游服务器接收到无效的响应。
504 Gateway Time-out：作为网关或者代理工作的服务器尝试执行请求时，未能及时从上游服务器（URI标识出的服务器，例如HTTP、FTP、LDAP）或者辅助服务器（例如DNS）收到响应。
三.502 Bad Gateway原因分析
将请求提交给网关如php-fpm执行，但是由于某些原因没有执行完毕导致php-fpm进程终止执行。说到此，这个问题就很明了了，与网关服务如php-fpm的配置有关了。f配置文件中有两个参数就需要你考虑到，分别是max_children和request_terminate_timeout。arrive是什么意思
max_children最大子进程数，在高并发请求下，达到php-fpm最大响应数，后续的请求就会出现502错误的。可以通过netstat命令来查看当前连接数。
request_terminate_timeout设置单个请求的超时终止时间。还应该注意到php.ini中的max_cir
execution_time参数。当请求终止时，也会出现502错误的。
当积累了大量的php请求，你重启php-fpm释放资源，但一两分钟不到，502又再次呈现，这是什么原因导致的呢？ 这时还应该考虑到数据库，查看下数据库进程是否有大量的locked进程，数据库死锁导致超时，前端终止了继续请求，但是SQL语句还在等待释放锁，这时就要重启数据库服务了或kill掉死锁SQL进程了。
对于长时间的请求可以考虑使用异步方式，可以参阅《关于PHP实现异步操作的研究》。
四.504 Gateway Time-out原因分析
504错误一般是与f配置有关了。主要与以下几个参数有关：fastcgi_connect_timeout、fastcgi_nd_timeout、fastcgi_read_timeout、fastcgi_buffer_size、fastcgi_buffers、fastcgi_busy_buffers_size、fastcgi_temp_file_write_size、fastcgi_intercept_errors。特别是前三个超时时间。如果fastcgi缓冲区太小会导致fastcgi进程被挂起从而演变为504错误。
五.小结
总而言之，502错误主要从四个方向入手： 1.max_quest_terminate_timeout、max_execution_time 3.数据库
2010年高考英语
4.网关服务是否启动如php-fpm 504错误主要查看f关于网关如fastcgi的配置。
第二篇：BUSYBOX编译错误及解决方法总结
编译busybox的组合：important是什么意思
busybox-1.0.0 arm-linux-gcc-2.95.3(AT91rm9200开发板)
经典参考：
移植基本过程：
在[build options]中选择[Build busybox as a static binary] 主要是C库的连接方式，安装目录等。5.make 6.创建rootfs目录 7.make installdialogbox>贿赂英文
编译过程可能出现以下错误，解决方法如下：
可能会出现的错误：
1.出现如下错误
CC miscutils/taskt.o miscutils/taskt.c:17: error: par error before '*' token miscutils/taskt.c:18: warning: function declaration isn't a prototype miscutils/taskt.c: In function `__from_cput':
miscutils/taskt.c:22: error: `CPU_SETSIZE' undeclared(first u in this function)
miscutils/taskt.c:22: error:(Each undeclared identifier is reported only once miscutils/taskt.c:22: error: for each function it appears in.)miscutils/taskt.c:26: warning: implicit declaration of function `CPU_ISSET' miscutils/taskt.c:26: error: `mask' undeclared(first u in this function)miscutils/taskt.c: In function `taskt_main': miscutils/taskt.c:47: error: `cpu_t_t' undeclared(first u in this function)
miscutils/taskt.c:47: error: par error before “mask” miscutils/taskt.c:68: warning: implicit declaration of function `CPU_ZERO' miscutils/taskt.c:68: error: `new_mask' und
eclared(first u in this function)
miscutils/taskt.c:69: error: `CPU_SETSIZE' undeclared(first u in this function)miscutils/taskt.c:71: warning: implicit declaration of function `CPU_SET'
miscutils/taskt.c:78: error: `mask' undeclared(first u in this function)
make[1]: *** [miscutils/taskt.o] Error 1
make: *** [miscutils] Error 2
make menuconfig 找到[Miscellaneous Utilities],去掉[task t]
2.如下错误：
伊恩 萨默海尔德time.c libbb/time.c:20: error: “CLOCK_MONOTONIC” undeclared(first u in this function)make menuconfig
去掉Busybox Settings->Busybox Library Tuning->[]U clock_gettie(CLOCK_MONOTONIC)syscall
insurance是什么意思
anniversary3.出现如下错误：
In file included from /usr/local/arm/2.95.3/lib/gcc-lib/arm-linux/2.95.3/../../../../arm-linux/sys-include/linux/fs.h:12，from /usr/local/arm/2.95.3/lib/gcc-lib/arm-linux/2.95.3/../../../../arm-linux/sys-include/linux/capability.h:17，from /usr/local/arm/2.95.3/lib/gcc-lib/arm-linux/2.95.3/../../../../arm-linux/sys-include/linux/binfmts.h:5，from /usr/local/arm/2.95.3/lib/gcc-lib/arm-linux/2.95.3/../../../../arm-linux/sys-include/linux/sched.h:9，from /usr/local/arm/2.95.3/lib/gcc-lib/arm-linux/2.95.3/../../../../arm-linux/sys-include/net/inetpeer.h:14，from /usr/local/arm/2.95.3/lib/gcc-lib/arm-linux/2.95.3/../../../../arm-linux/sys-include/net/route.h:28，from /busybox-1.01/networking/route.c:42: /usr/local/arm/2.95.3/lib/gcc-lib/arm-linux/2.95.3/../../../../arm-linux/sys-include/linux/wait.h:4: warning: `WNOHANG' redefined /usr/local/arm/2.95.3/lib/gcc-lib/arm-linux/2.95.3/../../../../arm-linux/include/bits/waitflags.h:26: warning: this is the location of the previous definition /usr/local/arm/2.95.3/lib/gcc-lib/arm-linux/2.95.3/../../../../arm-linux/sys-include/linux/wait.h:
5: warning: `WUNTRACED' redefined /usr/local/arm/2.95.3/lib/gcc-lib/arm-linux/2.95.3/../../../../arm-linux/include/bits/waitflags.h:27: warning: this is the location of the previous definition In file included from /usr/local/arm/2.95.3/lib/gcc-lib/arm-linux/2.95.3/../../../../arm-linux/sys-include/linux/sched.h:77，from /usr/local/arm/2.95.3/lib/gcc-lib/arm-linux/2.95.3/../../../../arm-linux/sys-include/net/inetpeer.h:14，from /usr/local/arm/2.95.3/lib/gcc-lib/arm-linux/2.95.3/../../../../arm-linux/sys-include/net/route.h:28，from /busybox-1.01/networking/route.c:42: /usr/local/arm/2.95.3/lib/gcc-lib/arm-linux/2.95.3/../../../../arm-linux/sys-include/linux/time.h:108: warning: `FD_SET' redefined /usr/local/arm/2.95.3/lib/gcc-lib/arm-linux/2.95.3/../../../../arm-linux/include/sys/lect.h:83: warning: this is the location of the previous definition /usr/local/arm/2.95.3/lib/gcc-lib/arm-linux/2.95.3/../../../../arm-linux/sys-include/linux/time.h:109: warning: `FD_CLR' redefined /usr/local/arm/2.95.3/lib/gcc-lib/arm-linux/2.95.3/../../../../arm-linux/include/sys/lect.h:84: warning: this is the location of the previous definition /usr/local/arm/2.95.3/lib/gcc-lib/arm-linux/2.95.3/../../../../arm-linux/sys-include/linux/time.h:110: warning: `FD_ISSET' redefine
d /usr/local/arm/2.95.3/lib/gcc-lib/arm-linux/2.95.3/../../../../arm-linux/include/sys/lect.h:85: warning: this is the location of the previous definition /usr/local/arm/2.95.3/lib/gcc-lib/arm-linux/2.95.3/../../../../arm-linux/sys-include/linux/time.h:111: warning: `FD_ZERO' redefined /usr/local/arm/2.95.3/lib/gcc-lib/arm-linux/2.95.3/../../../../arm-linux/include/sys/lect.h:86: warning: this is the location of the previous definition In file included from /busybox-1.01/networking/route.c:42: /usr/local/arm/2.95.3/lib/gcc-lib/arm-linux/2.95.3/../../../../arm-linux/sys-include/net/route.h:34: warning: #warning This file is not suppod to be ud outside of kernel.…… ……
In file included from /usr/local/arm/2.95.3/lib/gcc-lib/arm-linux/2.95.3/../../../../arm-linux/include/netdb.h:38，from /busybox-1.01/include/libbb.h:36，from /busybox-1.01/include/busybox.h:54，from /busybox-1.01/networking/route.c:44: /usr/local/arm/2.95.3/lib/gcc-lib/arm-linux/2.95.3/../../../../arm-linux/include/bits/siginfo.h:34: redefinition of `union sigval' /usr/local/arm/2.95.3/lib/gcc-lib/arm-linux/2.95.3/../../../../arm-linux/include/bits/siginfo.h:37: warning: redefinition of `sig
val_t' /usr/local/arm/2.95.3/lib/gcc-lib/arm-linux/2.95.3/../../../../arm-linux/sys-include/asm/siginfo.h:11: warning: `sigval_t' previously declared here /usr/local/arm/2.95.3/lib/gcc-lib/arm-linux/2.95.3/../../../../arm-linux/include/bits/siginfo.h:274: redefinition of `struct sigevent' /usr/local/arm/2.95.3/lib/gcc-lib/arm-linux/2.95.3/../../../../arm-linux/include/bits/siginfo.h:289: warning: redefinition of `sigevent_t' /usr/local/arm/2.95.3/lib/gcc-lib/arm-linux/2.95.3/../../../../arm-linux/sys-include/asm/siginfo.h:211: warning: `sigevent_t' previously declared here /usr/local/arm/2.95.3/lib/gcc-lib/arm-linux/2.95.3/../../../../arm-linux/include/bits/siginfo.h:298: par error before `0' In file included from /busybox-1.01/include/busybox.h:54，from /busybox-1.01/networking/route.c:44: /busybox-1.01/include/libbb.h:112: warning: declaration of `flags' shadows global declaration /busybox-1.01/include/libbb.h:113: warning: declaration of `flags' shadows global declaration /busybox-1.01/include/libbb.h:135: warning: declaration of `flags' shadows global declaration /busybox-1.01/include/libbb.h:251: warning: declaration of `flags' shado
ws global declaration /busybox-1.01/include/libbb.h:256: redefinition of `struct sysinfo' /busybox-1.01/include/libbb.h:272: warning: declaration of `info' shadows global declaration /busybox-1.01/include/libbb.h:309: warning: declaration of `flags' shadows global declaration /busybox-1.01/include/libbb.h:440: warning: declaration of `flags' shadows global declaration /busybox-1.01/networking/route.c:475: warning: declaration of `flags' shadows global declaration /busybox-1.01/networking/route.c: In function `t_flags': /busybox-1.01/networking/route.c:476: warning: declaration of `flags' shadows global declaration /busybox-1.01/networking/route.c: In function `displayroutes': /busybox-1.01/networking/route.c:490: warning: declaration of `flags' shadows global declaration make: *** [/busybox-1.01/networking/route.o] Error 1 去掉Busybox Settings->NetWork device-->[]route
